As specifi ed in Title 14 of the Code of Federal Regulations
(14 CFR) part 91, no person may operate an aircraft in
controlled airspace under IFR unless that person has fi led an
IFR fl ight plan. Flight plans may be submitted to the nearest
AFSS or air traffi c control tower (ATCT) either in person,
by telephone (1-800-WX-BRIEF), by computer (using the
direct user access terminal system (DUATS)), or by radio
if no other means are available. Pilots should fi le IFR fl ight
plans at least 30 minutes prior to estimated time of departure
to preclude possible delay in receiving a departure clearance
from ATC. The AIM provides guidance for completing
and fi ling FAA Form 7233-1, Flight Plan. These forms are
available at fl ight service stations (FSSs), and are generally
found in fl ight planning rooms at airport terminal buildings.
Filing in Flight
IFR fl ight plans may be fi led from the air under various
conditions, including:
1. A fl ight outside controlled airspace before proceeding
into IFR conditions in controlled airspace.
2. A VFR fl ight expecting IFR weather conditions en
route in controlled airspace.
In either of these situations, the fl ight plan may be fi led with
the nearest AFSS or directly with the ARTCC. A pilot who
fi les with the AFSS submits the information normally entered
during preflight filing, except for “point of departure,”
together with present position and altitude. AFSS then
relays this information to the ARTCC. The ARTCC will
then clear the pilot from present position or from a specifi ed
navigation fi x.
10-3
Figure 10-1. Flight Plan Form.
A pilot who fi les directly with the ARTCC reports present
position and altitude, and submits only the flight plan
information normally relayed from the AFSS to the ARTCC.
Be aware that traffi c saturation frequently prevents ARTCC
personnel from accepting fl ight plans by radio. In such
cases, a pilot is advised to contact the nearest AFSS to fi le
the fl ight plan.
Cancelling IFR Flight Plans
An IFR fl ight plan may be cancelled any time a pilot is
operating in VFR conditions outside Class A airspace by
stating “cancel my IFR fl ight plan” to the controller or air-toground
station. After cancelling an IFR fl ight plan, the pilot
should change to the appropriate air-to-ground frequency,
transponder code as directed, and VFR altitude/fl ight level.
ATC separation and information services (including radar
services, where applicable) are discontinued when an IFR
fl ight plan is cancelled. If VFR radar advisory service is
desired, a pilot must specifi cally request it. Be aware that
other procedures may apply when cancelling an IFR fl ight
plan within areas such as Class C or Class B airspace.
When operating on an IFR fl ight plan to an airport with
an operating control tower, a flight plan is cancelled
automatically upon landing. If operating on an IFR fl ight
plan to an airport without an operating control tower, the
pilot is responsible for cancelling the fl ight plan. This can
be done by telephone after landing if there is no operating
FSS or other means of direct communications with ATC.
When there is no FSS or air-to-ground communications are
not possible below a certain altitude, a pilot may cancel an
IFR fl ight plan while still airborne and able to communicate
with ATC by radio. If using this procedure, be certain the
remainder of the fl ight can be conducted under VFR. It is
essential that IFR fl ight plans be cancelled expeditiously. This
allows other IFR traffi c to utilize the airspace.
Clearances
An ATC clearance allows an aircraft to proceed under
specifi ed traffi c conditions within controlled airspace for the
purpose of providing separation between known aircraft.
Examples
A fl ight fi led for a short distance at a relatively low altitude
in an area of low traffi c density might receive a clearance
as follows:
“Cessna 1230 Alpha, cleared to Doeville airport direct,
cruise 5,000.”
10-4
The term “cruise” in this clearance means a pilot is authorized
to fl y at any altitude from the minimum IFR altitude up to and
including 5,000 feet, and may level off at any altitude within
this block of airspace. A climb or descent within the block may
be made at the pilot’s discretion. However, once a pilot reports
leaving an altitude within the block, the pilot may not return to
that altitude without further ATC clearance.
When ATC issues a cruise clearance in conjunction with an
unpublished route, an appropriate crossing altitude will be
specifi ed to ensure terrain clearance until the aircraft reaches a
fi x, point, or route where the altitude information is available.
The crossing altitude ensures IFR obstruction clearance to
the point at which the aircraft enters a segment of a published
route or IAP.
Once a fl ight plan is fi led, ATC will issue the clearance with
appropriate instructions, such as the following:
“Cessna 1230 Alpha is cleared to Skyline airport via
the Crossville 055 radial, Victor 18, maintain 5,000.
Clearance void if not off by 1330.”
Or a more complex clearance, such as:
“Cessna 1230 Alpha is cleared to Wichita Mid-continent
airport via Victor 77, left turn after takeoff, proceed
direct to the Oklahoma City VORTAC. Hold west on
the Oklahoma City 277 radial, climb to 5,000 in holding
pattern before proceeding on course. Maintain 5,000 to
CASHION intersection. Climb to and maintain 7,000.
Departure control frequency will be 121.05, Squawk
0412.”
Clearance delivery may issue the following “abbreviated
clearance” which includes a departure procedure (DP):
“Cessna 1230 Alpha, cleared to La Guardia as fi led,
RINGOES 8 departure Phillipsburg transition, maintain
8,000. Departure control frequency will be 120.4,
Squawk 0700.”
This clearance may be readily copied in shorthand as follows:
“CAF RNGO8 PSB M80 DPC 120.4 SQ 0700.”
The information contained in this DP clearance is abbreviated
using clearance shorthand (see appendix 1). The pilot should
know the locations of the specifi ed navigation facilities, together
with the route and point-to-point time, before accepting the
clearance.
The DP enables a pilot to study and understand the details
of a departure before fi ling an IFR fl ight plan. It provides
the information necessary to set up communication and
navigation equipment and be ready for departure before
requesting an IFR clearance.
Once the clearance is accepted, a pilot is required to comply
with ATC instructions. A clearance different from that issued
may be requested if the pilot considers another course of action
more practicable or if aircraft equipment limitations or other
considerations make acceptance of the clearance inadvisable.
A pilot should also request clarifi cation or amendment, as
appropriate, any time a clearance is not fully understood
or considered unacceptable for safety of fl ight. The pilot is
responsible for requesting an amended clearance if ATC issues
a clearance that would cause a pilot to deviate from a rule or
regulation or would place the aircraft in jeopardy.
Clearance Separations
ATC will provide the pilot on an IFR clearance with separation
from other IFR traffi c. This separation is provided:
1. Vertically—by assignment of different altitudes.
2. Longitudinally—by controlling time separation between
aircraft on the same course.
3. Laterally—by assignment of different fl ight paths.
4. By radar—including all of the above.
ATC does not provide separation for an aircraft operating:
1. Outside controlled airspace.
2. On an IFR clearance:
a) With “VFR-On-Top” authorized instead of a
specifi c assigned altitude.
b) Specifying climb or descent in “VFR conditions.”
c) At any time in VFR conditions, since uncontrolled
VFR flights may be operating in the same
airspace.
In addition to heading and altitude assignments, ATC will
occasionally issue speed adjustments to maintain the required
separations. For example:
“Cessna 30 Alpha, slow to 100 knots.”
A pilot who receives speed adjustments is expected to maintain
that speed plus or minus 10 knots. If for any reason the pilot
is not able to accept a speed restriction, the pilot should advise
ATC.
At times, ATC may also employ visual separation techniques
to keep aircraft safely separated. A pilot who obtains visual
contact with another aircraft may be asked to maintain visual
separation or to follow the aircraft. For example:
10-5
“Cessna 30 Alpha, maintain visual separation with that
traffi c, climb and maintain 7,000.”
The pilot’s acceptance of instructions to maintain visual
separation or to follow another aircraft is an acknowledgment
that the aircraft will be maneuvered as necessary, to maintain
safe separation. It is also an acknowledgment that the pilot
accepts the responsibility for wake turbulence avoidance.
In the absence of radar contact, ATC will rely on position
reports to assist in maintaining proper separation. Using the data
transmitted by the pilot, the controller follows the progress of
each fl ight. ATC must correlate the pilots’ reports to provide
separation; therefore, the accuracy of each pilot’s report can
affect the progress and safety of every other aircraft operating
in the area on an IFR fl ight plan.
Departure Procedures (DPs)
Instrument departure procedures are preplanned instrument
flight rule (IFR) procedures, which provide obstruction
clearance from the terminal area to the appropriate en route
structure and provide the pilot with a way to depart the airport
and transition to the en route structure safely. Pilots operating
under 14 CFR part 91 are strongly encouraged to fi le and fl y a
DP when one is available.
There are two types of DPs, Obstacle Departure Procedures
(ODP), printed either textually or graphically, and Standard
Instrument Departures (SID), always printed graphically. All
DPs, either textual or graphic, may be designed using either
conventional or RNAV criteria. RNAV procedures will have
RNAV printed in the title, e.g., SHEAD TWO DEPARTURE
(RNAV).
Obstacle Departure Procedures (ODP)
ODPs provide obstruction clearance via the least onerous route
from the terminal area to the appropriate en route structure. ODPs
are recommended for obstruction clearance and may be fl own
without ATC clearance unless an alternate departure procedure
(SID or radar vector) has been specifi cally assigned by ATC.
Graphic ODPs will have (OBSTACLE) printed in the procedure
title, e.g., GEYSR THREE DEPARTURE (OBSTACLE),
CROWN ONE DEPARTURE (RNAV)(OBSTACLE).
Standard Instrument Departures
Standard Instrument Departures (SID) are air traffi c control
(ATC) procedures printed for pilot/controller use in graphic
form to provide obstruction clearance and a transition from
the terminal area to the appropriate en route structure. SIDs
are primarily designed for system enhancement and to reduce
pilot/controller workload. ATC clearance must be received
prior to fl ying a SID.
ODPs are found in section C of each booklet published
regionally by the NACG, TPP, along with “IFR Take-off
Minimums” while SIDs are collocated with the approach
procedures for the applicable airport. Additional information
on the development of DPs can be found in paragraph 5-2-7
of the AIM. However, the following points are important
to remember.
1. The pilot of IFR aircraft operating from locations
where DP procedures are effective may expect an ATC
clearance containing a DP. The use of a DP requires
pilot possession of at least the textual description of the
approved DP.
2. If a pilot does not possess a preprinted DP or for any other
reason does not wish to use a DP, he or she is expected
to advise ATC. Notifi cation may be accomplished by
fi ling “NO DP” in the remarks section of the fi led fl ight
plan, or by advising ATC.
3. If a DP is accepted in a clearance, a pilot must comply
with it.
Radar Controlled Departures
On IFR departures from airports in congested areas, a pilot
will normally receive navigational guidance from departure
control by radar vector. When a departure is to be vectored
immediately following takeoff, the pilot will be advised before
takeoff of the initial heading to be fl own. This information is
vital in the event of a loss of two-way radio communications
during departure.
The radar departure is normally simple. Following takeoff,
contact departure control on the assigned frequency when
advised to do so by the control tower. At this time departure
control verifi es radar contact, and gives headings, altitude, and
climb instructions to move an aircraft quickly and safely out of
the terminal area. A pilot is expected to fl y the assigned headings
and altitudes until informed by the controller of the aircraft’s
position with respect to the route given in the clearance, whom
to contact next, and to “resume own navigation.”
Departure control will provide vectors to either a navigation
facility, or an en route position appropriate to the departure
clearance, or transfer to another controller with further radar
surveillance capabilities.
A radar controlled departure does not relieve the pilot of
responsibilities as pilot-in-command. Be prepared before
takeoff to conduct navigation according to the ATC clearance,
with navigation receivers checked and properly tuned. While
under radar control, monitor instruments to ensure continuous
orientation to the route specifi ed in the clearance, and record
the time over designated checkpoints.
10-6
Figure 10-2. Departure Procedure (DP).
10-7
Position Reports
Position reports are required over each compulsory reporting
point (shown on the chart as a solid triangle) along the route
being fl own regardless of altitude, including those with
a VFR-on-top clearance. Along direct routes, reports are
required of all IFR fl ights over each point used to defi ne
the route of fl ight. Reports at reporting points (shown as an
open triangle) are made only when requested by ATC. A
pilot should discontinue position reporting over designated
reporting points when informed by ATC that the aircraft
is in “RADAR CONTACT.” Position reporting should be
resumed when ATC advises “RADAR CONTACT LOST”
or “RADAR SERVICE TERMINATED.”
Position reports should include the following items:
1. Identifi cation
2. Position
3. Time
4. Altitude or fl ight level (include actual altitude or fl ight
level when operating on a clearance specifying VFRon-
top)
5. Type of fl ight plan (not required in IFR position reports
made directly to ARTCCs or approach control)
6. ETA and name of next reporting point
7. The name only of the next succeeding reporting point
along the route of fl ight
8. Pertinent remarks
En route position reports are submitted normally to
the ARTCC controllers via direct controller-to-pilot
communications channels, using the appropriate ARTCC
frequencies listed on the en route chart.
Whenever an initial contact with a controller is to be followed
by a position report, the name of the reporting point should
be included in the call-up. This alerts the controller that such
information is forthcoming. For example:
“Atlanta Center, Cessna 1230 Alpha at JAILS
intersection.”
“Cessna 1230 Alpha Atlanta Center.”
“Atlanta Center, Cessna 1230 Alpha at JAILS
intersection, 5,000, estimating Monroeville at
1730.”
Additional Reports
In addition to required position reports, the following reports
should be made to ATC without a specifi c request.
Departures From Airports Without an Operating
Control Tower
When departing from airports that have neither an operating
tower nor an FSS, a pilot should telephone the fl ight plan to the
nearest ATC facility at least 30 minutes before the estimated
departure time. If weather conditions permit, depart VFR and
request IFR clearance as soon as radio contact is established
with ATC.
If weather conditions make it undesirable to fl y VFR, telephone
clearance request. In this case, the controller would probably
issue a short-range clearance pending establishment of radio
contact, and might restrict the departure time to a certain period.
For example:
“Clearance void if not off by 0900.”
This would authorize departure within the allotted period and
permit a pilot to proceed in accordance with the clearance. In
the absence of any specifi c departure instructions, a pilot would
be expected to proceed on course via the most direct route.
En Route Procedures
Procedures en route will vary according to the proposed route,
the traffi c environment, and the ATC facilities controlling
the fl ight. Some IFR fl ights are under radar surveillance and
controlled from departure to arrival, and others rely entirely
on pilot navigation.
Where ATC has no jurisdiction, it does not issue an IFR
clearance. It has no control over the fl ight, nor does the pilot
have any assurance of separation from other traffi c.
ATC Reports
All pilots are required to report unforecast weather conditions
or other information related to safety of fl ight to ATC. The
pilot-in-command of each aircraft operated in controlled
airspace under IFR shall report as soon as practical to ATC any
malfunctions of navigational, approach, or communication
equipment occurring in fl ight:
1. Loss of VOR, tactical air navigation (TACAN) or
automatic direction fi nder (ADF) receiver capability.
2. Complete or partial loss of instrument landing system
(ILS) receiver capability.
3. Impairment of air-to-ground communications
capability.
The pilot-in-command shall include within the report
(1) Aircraft identifi cation, (2) Equipment affected, (3) Degree
to which the pilot to operate under IFR within the ATC
system is impaired, and (4) Nature and extent of assistance
desired from ATC.
10-8
Planning the Descent and Approach
ATC arrival procedures and fl ight deck workload are affected
by weather conditions, traffi c density, aircraft equipment,
and radar availability.
When landing at an airport with approach control services
and where two or more IAPs are published, information on
the type of approach to expect will be provided in advance of
arrival or vectors will be provided to a visual approach. This
information will be broadcast either on automated terminal
information service (ATIS) or by a controller. It will not be
furnished when the visibility is 3 miles or more and the ceiling
is at or above the highest initial approach altitude established
for any low altitude IAP for the airport.
The purpose of this information is to help the pilot plan arrival
actions; however, it is not an ATC clearance or commitment
and is subject to change. Fluctuating weather, shifting
winds, blocked runway, etc., are conditions that may result
in changes to the approach information previously received.
It is important for a pilot to advise ATC immediately if he
or she is unable to execute the approach or prefers another
type of approach.
If the destination is an airport without an operating control
tower, and has automated weather data with broadcast
capability, the pilot should monitor the automated surface
observing system/automated weather observing system
(ASOS/AWOS) frequency to ascertain the current weather for
the airport. ATC should be advised that weather information
has been received and what the pilot’s intentions are.
When the approach to be executed has been determined, the
pilot should plan for and request a descent to the appropriate
altitude prior to the initial approach fi x (IAF) or transition
route depicted on the IAP. When fl ying the transition route,
a pilot should maintain the last assigned altitude until ATC
gives the instructions “cleared for the approach.” Lower
altitudes can be requested to bring the transition route
altitude closer to the required altitude at the initial approach
fi x. When ATC uses the phrase “at pilot’s discretion” in the
altitude information of a clearance, the pilot has the option
to start a descent at any rate, and may level off temporarily
at any intermediate altitude. However, once an altitude has
been vacated, return to that altitude is not authorized without
a clearance. When ATC has not used the term “at pilot’s
discretion” nor imposed any descent restrictions, initiate
descent promptly upon acknowledgment of the clearance.
Descend at an optimum rate (consistent with the operating
characteristics of the aircraft) to 1,000 feet above the assigned
altitude. Then attempt to descend at a rate of between 500 and
1. At all times:
a) When vacating any previously assigned altitude
or fl ight level for a newly assigned altitude or
fl ight level
b) When an altitude change will be made if operating
on a clearance specifying VFR-on-top
c) When unable to climb/descend at a rate of at least
500 feet per minute (fpm)
d) When an approach has been missed (Request
clearance for specific action (to alternative
airport, another approach, etc.))
e) Change in average true airspeed (at cruising
altitude) when it varies by 5 percent or ten knots
(whichever is greater) from that fi led in the fl ight
plan
f) The time and altitude upon reaching a holding fi x
or point to which cleared
g) When leaving any assigned holding fi x or point
NOTE - The reports in (f) and (g) may be omitted
by pilots of aircraft involved in instrument
training at military terminal area facilities when
radar service is being provided.
h) Any loss in controlled airspace of VOR,
TACAN, ADF, low frequency navigation
receiver capability, GPS anomalies while using
installed IFR-certified GPS/GNSS receivers,
complete or partial loss of ILS receiver capability,
or impairment of air/ground communications
capability. Reports should include aircraft
identification, equipment affected, degree to
which the capability to operate under IFR in
the ATC system is impaired, and the nature and
extent of assistance desired from ATC.
i) Any information relating to the safety of fl ight.
2. When not in radar contact:
a) When leaving the fi nal approach fi x inbound
on fi nal approach (nonprecision approach), or
when leaving the outer marker or fi x used in lieu
of the outer marker inbound on fi nal approach
(precision approach).
b) A corrected estimate at any time it becomes
apparent that an estimate as previously submitted
is in error in excess of 3 minutes.
Any pilot who encounters weather conditions that have not
been forecast, or hazardous conditions which have been
forecast, is expected to forward a report of such weather
to ATC.
10-9
1,500 fpm until the assigned altitude is reached. If at anytime
a pilot is unable to maintain a descent rate of at least 500 fpm,
advise ATC. Also advise ATC if it is necessary to level off
at an intermediate altitude during descent. An exception to
this is when leveling off at 10,000 feet mean sea level (MSL)
on descent, or 2,500 feet above airport elevation (prior to
entering a Class B, Class C, or Class D surface area) when
required for speed reduction.
Standard Terminal Arrival Routes (STARs)
Standard terminal arrival routes (as described in Chapter
8) have been established to simplify clearance delivery
procedures for arriving aircraft at certain areas having high
density traffi c. A STAR serves a purpose parallel to that of a
DP for departing traffi c. The following points
regarding STARs are important to remember:
1. All STARs are contained in the TPP, along with the
IAP charts for the destination airport. The AIM also
describes STAR procedures.
2. If the destination is a location for which STARs
have been published, a pilot may be issued a
clearance containing a STAR whenever ATC deems
it appropriate. To accept the clearance, a pilot must
possess at least the approved textual description.
3. It is the pilot’s responsibility to either accept or refuse
an issued STAR. If a STAR will not or cannot be used,
advise ATC by placing “NO STAR” in the remarks
section of the fi led fl ight plan or by advising ATC.
4. If a STAR is accepted in a clearance, compliance is
mandatory.
Substitutes for Inoperative or Unusable
Components
The basic ground components of an ILS are the localizer,
glide slope, outer marker, middle marker, and inner marker
(when installed). A compass locator or precision radar may
be substituted for the outer or middle marker. Distance
measuring equipment (DME), VOR, or nondirectional beacon
(NDB) fi xes authorized in the standard IAP or surveillance
radar may be substituted for the outer marker.
Additionally, IFR-certifi ed global positioning system (GPS)
equipment, operated in accordance with Advisory Circular
(AC) 90-94, Guidelines for Using Global Positioning System
Equipment for IFR En Route and Terminal Operations and
for Nonprecision Instrument Approaches in the United
States National Airspace System, may be substituted for
ADF and DME equipment, except when fl ying NDB IAP.
Specifi cally, GPS can be substituted for ADF and DME
equipment when:
1. Flying a DME arc;
2. Navigating TO/FROM an NDB;
3. Determining the aircraft position over an NDB;
4. Determining the aircraft position over a fi x made up
of a crossing NDB bearing;
5. Holding over an NDB;
6. Determining aircraft position over a DME fi x.
Holding Procedures
Depending upon traffi c and weather conditions, holding may
be required. Holding is a predetermined maneuver which
keeps aircraft within a specifi ed airspace while awaiting
further clearance from ATC. A standard holding pattern
uses right turns, and a nonstandard holding pattern uses left
turns. The ATC clearance will always specify left turns when
a nonstandard pattern is to be fl own.
Standard Holding Pattern (No Wind)
In a standard holding pattern with no winds, the
aircraft follows the specifi ed course inbound to the holding
fi x, turns 180° to the right, fl ies a parallel straight course
outbound for 1 minute, turns 180° to the right, and fl ies the
inbound course to the fi x.
Standard Holding Pattern (With Wind)
A standard symmetrical holding pattern cannot be fl own
when winds exist. In those situations, the pilot is expected
to:
1. Compensate for the effect of a known wind except
when turning.
2. Adjust outbound timing to achieve a 1-minute (1-1/2
minutes above 14,000 feet) inbound leg.
Figure 10-5 illustrates the holding track followed with a left
crosswind. The effect of wind is counteracted by applying
drift corrections to the inbound and outbound legs and by
applying time allowances to the outbound leg.
Holding Instructions
If an aircraft arrives at a clearance limit before receiving
clearance beyond the fi x, ATC expects the pilot to maintain
the last assigned altitude and begin holding in accordance
with the charted holding pattern. If no holding pattern is
charted and holding instructions have not been issued, enter
a standard holding pattern on the course on which the aircraft
approached the fi x and request further clearance as soon
as possible. Normally, when no delay is anticipated, ATC
will issue holding instructions at least 5 minutes before the
10-10
Figure 10-3. Standard Terminal Arrival Route (STAR).
10-11
Figure 10-4. Standard Holding Pattern—No Wind.
Figure 10-5. Drift Correction in Holding Pattern.
estimated arrival at the fi x. Where a holding pattern is not
charted, the ATC clearance will specify the following:
1. Direction of holding from the fi x in terms of the eight
cardinal compass points (N, NE, E, SE, etc.)
2. Holding fi x (the fi x may be omitted if included at the
beginning of the transmission as the clearance limit)
3. Radial, course, bearing, airway, or route on which the
aircraft is to hold.
4. Leg length in miles if DME or area navigation
(RNAV) is to be used (leg length will be specifi ed in
minutes on pilot request or if the controller considers
it necessary).
5. Direction of turn, if left turns are to be made, because
the pilot requests or the controller considers it
necessary.
6. Time to expect-further-clearance (EFC) and any
pertinent additional delay information.
ATC instructions will also be issued whenever:
1. It is determined that a delay will exceed 1 hour.
2. A revised EFC is necessary.
3. In a terminal area having a number of navigation
aids and approach procedures, a clearance limit may
not indicate clearly which approach procedures will
be used. On initial contact, or as soon as possible
thereafter, approach control will advise the pilot of
the type of approach to expect.
4. Ceiling and/or visibility is reported as being at or
below the highest “circling minimums” established
for the airport concerned. ATC will transmit a report
of current weather conditions and subsequent changes,
as necessary.
5. An aircraft is holding while awaiting approach
clearance, and the pilot advises ATC that reported
weather conditions are below minimums applicable
to the operation. In this event, ATC will issue suitable
instructions to aircraft desiring either to continue
holding while awaiting weather improvement or
proceed to another airport.
Standard Entry Procedures
The entry procedures given in the AIM evolved from
extensive experimentation under a wide range of operational
conditions. The standardized procedures should be followed
to ensure that an aircraft remains within the boundaries of
the prescribed holding airspace.
When a speed reduction is required, start the reduction when
3 minutes or less from the holding fi x. Cross the holding fi x
initially at or below the maximum holding airspeed (MHA).
The purpose of the speed reduction is to prevent overshooting
the holding airspace limits, especially at locations where
adjacent holding patterns are close together.
All aircraft may hold at the following altitudes and maximum
holding airspeeds:
Altitude Mean Sea Level (MSL) Airspeed (KIAS)
Up to 6,000 feet 200
6,001 – 14,000 feet 230
14,001 feet and above 265
10-12
Figure 10-6. Holding Pattern Entry Procedures.
The following are exceptions to the maximum holding
airspeeds:
1. Holding patterns from 6,001 to 14,000 feet may
be restricted to a maximum airspeed of 210 knots
indicated airspeed (KIAS). This nonstandard pattern
is depicted by an icon.
2. Holding patterns may be restricted to a maximum
airspeed of 175 KIAS. This nonstandard pattern is
depicted by an icon. Holding patterns restricted to
175 KIAS are generally found on IAPs applicable to
category A and B aircraft only.
3. Holding patterns at Air Force airfi elds only—310
KIAS maximum, unless otherwise depicted.
4. Holding patterns at Navy airfi elds only—230 KIAS
maximum, unless otherwise depicted.
5. The pilot of an aircraft unable to comply with
maximum airspeed restrictions should notify ATC.
While other entry procedures may enable the aircraft to
enter the holding pattern and remain within protected
airspace, the parallel, teardrop, and direct entries are the
procedures for entry and holding recommended by the FAA.
Additionally, paragraph 5-3-7 in the AIM should be reviewed.
1. Parallel Procedure. When approaching the holding
fi x from anywhere in sector (a), the parallel entry
procedure would be to turn to a heading to parallel the
holding course outbound on the nonholding side for
1 minute, turn in the direction of the holding pattern
through more than 180°, and return to the holding fi x
or intercept the holding course inbound.
2. Teardrop Procedure. When approaching the holding
fi x from anywhere in sector (b), the teardrop entry
procedure would be to fl y to the fi x, turn outbound to
a heading for a 30° teardrop entry within the pattern
(on the holding side) for a period of 1 minute, then
turn in the direction of the holding pattern to intercept
the inbound holding course.
3. Direct Entry Procedure. When approaching the
holding fi x from anywhere in sector (c), the direct
entry procedure would be to fl y directly to the fi x and
turn to follow the holding pattern.
A pilot should make all turns during entry and while holding at:
1. 3° per second, or
2. 30° bank angle, or
3. A bank angle provided by a fl ight director system.
Time Factors
The holding pattern entry time reported to ATC is the initial
time of arrival over the fi x. Upon entering a holding pattern,
the initial outbound leg is fl own for 1 minute at or below
14,000 feet MSL, and for 1-1/2 minutes above 14,000
feet MSL. Timing for subsequent outbound legs should be
adjusted as necessary to achieve proper inbound leg time.
The pilot should begin outbound timing over or abeam the
fi x, whichever occurs later. If the abeam position cannot
be determined, start timing when the turn to outbound is
completed.
Time leaving the holding fi x must be known to ATC before
succeeding aircraft can be cleared to the vacated airspace.
Leave the holding fi x:
1. When ATC issues either further clearance en route or
approach clearance;
2. As prescribed in 14 CFR part 91 (for IFR operations;
two-way radio communications failure, and
responsibility and authority of the pilot-in-command);
or
3. After the IFR fl ight plan has been cancelled, if the
aircraft is holding in VFR conditions.
DME Holding
The same entry and holding procedures apply to DME
holding, but distances (nautical miles) are used instead of
time values. The length of the outbound leg will be specifi ed
by the controller, and the end of this leg is determined by
the DME readout.
Approaches
Compliance With Published Standard Instrument
Approach Procedures
Compliance with the approach procedures shown on the
approach charts provides necessary navigation guidance
information for alignment with the fi nal approach courses,
10-13
Figure 10-7. Holding—Outbound Timing.
as well as obstruction clearance. Under certain conditions, a
course reversal maneuver or procedure turn may be necessary.
However, this procedure is not authorized when:
1. The symbol “NoPT” appears on the approach course
on the plan view of the approach chart.
2. Radar vectoring is provided to the final approach
course.
3. A holding pattern is published in lieu of a procedure
turn.
4. Executing a timed approach from a holding fi x.
5. Otherwise directed by ATC.
Instrument Approaches to Civil Airports
Unless otherwise authorized, when an instrument letdown to
an airport is necessary, the pilot should use a standard IAP
prescribed for that airport. IAPs are depicted on IAP charts
and are found in the TPP.
ATC approach procedures depend upon the facilities available
at the terminal area, the type of instrument approach executed,
and the existing weather conditions. The ATC facilities,
navigation aids (NAVAIDs), and associated frequencies
appropriate to each standard instrument approach are given
on the approach chart. Individual charts are published for
standard approach procedures associated with the following
types of facilities:
1. Nondirectional beacon (NDB)
2. Very-high frequency omnirange (VOR)
3. Very-high frequency omnirange with distance
measuring equipment (VORTAC or VOR/DME)
4. Localizer (LOC)
5. Instrument landing system (ILS)
6. Localizer-type directional aid (LDA)
7. Simplifi ed directional facility (SDF)
8. Area navigation (RNAV)
9. Global positioning system (GPS)
An IAP can be fl own in one of two ways: as a full approach
or with the assistance of radar vectors. When the IAP is fl own
as a full approach, pilots conduct their own navigation using
the routes and altitudes depicted on the instrument approach
chart. A full approach allows the pilot to transition from
the en route phase, to the instrument approach, and then to
a landing with minimal assistance from ATC. This type of
procedure may be requested by the pilot but is most often
used in areas without radar coverage. A full approach also
provides the pilot with a means of completing an instrument
approach in the event of a communications failure.
When an approach is fl own with the assistance of radar vectors,
ATC provides guidance in the form of headings and altitudes
which position the aircraft to intercept the fi nal approach.
From this point, the pilot resumes navigation, intercepts the
fi nal approach course, and completes the approach using the
IAP chart. This is often a more expedient method of fl ying
the approach, as opposed to the full approach, and allows
ATC to sequence arriving traffi c. A pilot operating in radar
contact can generally expect the assistance of radar vectors
to the fi nal approach course.
10-14
Approach to Airport Without an Operating Control
Tower
Figure 10-8 shows an approach procedure at an airport
without an operating control tower. When approaching
such a facility, the pilot should monitor the AWOS/ASOS
if available for the latest weather conditions. When direct
communication between the pilot and controller is no longer
required, the ARTCC or approach controller will issue a
clearance for an instrument approach and advise “change to
advisory frequency approved.” When the aircraft arrives on
a “cruise” clearance, ATC will not issue further clearance
for approach and landing.
If an approach clearance is required, ATC will authorize
the pilot to execute his or her choice of standard instrument
approach (if more than one is published for the airport)
with the phrase “Cleared for the approach” and the
communications frequency change required, if any. From
this point on, there will be no contact with ATC. The pilot
is responsible for closing the IFR fl ight plan before landing,
if in VFR conditions, or by telephone after landing.
Unless otherwise authorized by ATC, a pilot is expected to
execute the complete IAP shown on the chart.
Approach to Airport With an Operating Tower,
With No Approach Control
When an aircraft approaches an airport with an operating
control tower, but no approach control, ATC will issue
a clearance to an approach/outer fi x with the appropriate
information and instructions as follows:
1. Name of the fi x
2. Altitude to be maintained
3. Holding information and expected approach clearance
time, if appropriate
4. Instructions regarding further communications,
including:
a) facility to be contacted
b) time and place of contact
c) frequency/ies to be used
If ATIS is available, a pilot should monitor that frequency
for information such as ceiling, visibility, wind direction and
velocity, altimeter setting, instrument approach, and runways
in use prior to initial radio contact with the tower. If ATIS is
not available, ATC will provide weather information from
the nearest reporting station.
Approach to an Airport With an Operating Tower,
With an Approach Control
Where radar is approved for approach control service, it is
used to provide vectors in conjunction with published IAPs.
Radar vectors can provide course guidance and expedite
traffi c to the fi nal approach course of any established IAP.
Figure 10-9 shows an IAP chart with maximum ATC
facilities available.
Approach control facilities that provide this radar service
operate in the following manner:
1. Arriving aircraft are either cleared to an outer fi x most
appropriate to the route being fl own with vertical
separation and, if required, given holding information;
or,
2. When radar hand-offs are effected between ARTCC
and approach control, or between two approach
control facilities, aircraft are cleared to the airport, or
to a fi x so located that the hand-off will be completed
prior to the time the aircraft reaches the fi x.
a) When the radar hand-offs are utilized, successive
arriving fl ights may be handed off to approach
control with radar separation in lieu of vertical
separation.
b) After hand-off to approach control, an aircraft
is vectored to the appropriate fi nal approach
course.
3. Radar vectors and altitude/fl ight levels are issued
as required for spacing and separating aircraft; do
not deviate from the headings issued by approach
control.
4. Aircraft are normally informed when it becomes
necessary to be vectored across the fi nal approach
course for spacing or other reasons. If approach
course crossing is imminent and the pilot has not
been informed that the aircraft will be vectored across
the fi nal approach course, the pilot should query the
controller. The pilot is not expected to turn inbound on
the fi nal approach course unless an approach clearance
has been issued. This clearance is normally issued with
the fi nal vector for interception of the fi nal approach
course, and the vector enables the pilot to establish the
aircraft on the fi nal approach course prior to reaching
the fi nal approach fi x.
5. Once the aircraft is established inbound on the fi nal
approach course, radar separation is maintained with
other aircraft, and the pilot is expected to complete
the approach using the NAVAID designated in the
clearance (ILS, VOR, NDB, GPS, etc.) as the primary
means of navigation.
10-15
Figure 10-8. Monroeville, AL (MVC) VOR or GPS Rwy 3 Approach: An Approach Procedure at an Airport Without an Operating
Control Tower.
10-16
Figure 10-9. Gulfport, MS (GPT) ILS or LOC Rwy 14 Approach: An Instrument Procedure Chart With Maximum ATC Facilities
Available.
10-17
Figure 10-10. Radar Instrument Approach Minimums for Troy, AL.
6. After passing the fi nal approach fi x inbound, the
pilot is expected to proceed direct to the airport and
complete the approach, or to execute the published
missed approach procedure.
7. Radar service is automatically terminated when the
landing is completed or when the pilot is instructed to
change to advisory frequency at uncontrolled airports,
whichever occurs fi rst.
Radar Approaches
With a radar approach, the pilot receives course and altitude
guidance from a controller who monitors the progress of the
fl ight with radar. This is an option should the pilot experience
an emergency or distress situation.
The only airborne radio equipment required for radar
approaches is a functioning radio transmitter and receiver.
The radar controller vectors the aircraft to align it with the
runway centerline. The controller continues the vectors to
keep the aircraft on course until the pilot can complete the
approach and landing by visual reference to the surface.
There are two types of radar approaches: Precision (PAR)
and Surveillance (ASR).
A radar approach may be given to any aircraft upon request
and may be offered to pilots of aircraft in distress or to expedite
traffi c; however, an ASR might not be approved unless
there is an ATC operational requirement, or in an unusual
or emergency situation. Acceptance of a PAR or ASR by a
pilot does not waive the prescribed weather minimums for the
airport or for the particular aircraft operator concerned. The
decision to make a radar approach when the reported weather
is below the established minimums rests with the pilot.
PAR and ASR minimums are published on separate pages
in the FAA Terminal Procedures Publication (TPP).
Figure 10-10.
Precision Approach (PAR) is one in which a controller
provides highly accurate navigational guidance in azimuth
and elevation to a pilot.
The controller gives the pilot headings to fl y that direct the
aircraft to, and keep the aircraft aligned with, the extended
centerline of the landing runway. The pilot is told to anticipate
glide path interception approximately 10 to 30 seconds before
it occurs and when to start descent. The published decision
height (DH) will be given only if the pilot requests it. If
the aircraft is observed to deviate above or below the glide
path, the pilot is given the relative amount of deviation by
use of terms “slightly” or “well” and is expected to adjust
the aircraft’s rate of descent/ascent to return to the glide
path. Trend information is also issued with respect to the
elevation of the aircraft and may be modifi ed by the terms
“rapidly” and “slowly”; e.g., “well above glide path, coming
down rapidly.”
Range from touchdown is given at least once each mile. If
an aircraft is observed by the controller to proceed outside
of specifi ed safety zone limits in azimuth and/or elevation
and continue to operate outside these prescribed limits, the
pilot will be directed to execute a missed approach or to fl y a
10-18
specifi ed course unless the pilot has the runway environment
(runway, approach lights, etc.) in sight. Navigational
guidance in azimuth and elevation is provided to the pilot
until the aircraft reaches the published DH. Advisory course
and glide path information is furnished by the controller
until the aircraft passes over the landing threshold. At this
point the pilot is advised of any deviation from the runway
centerline. Radar service is automatically terminated upon
completion of the approach.
Surveillance Approach (ASR) is one in which a controller
provides navigational guidance in azimuth only.
The controller furnishes the pilot with headings to fl y to
align the aircraft with the extended centerline of the landing
runway. Since the radar information used for a surveillance
approach is considerably less precise than that used for a
precision approach, the accuracy of the approach will not
be as great and higher minimums will apply. Guidance in
elevation is not possible but the pilot will be advised when to
commence descent to the Minimum Descent Altitude (MDA)
or, if appropriate, to an intermediate step-down fi x Minimum
Crossing Altitude and subsequently to the prescribed MDA.
In addition, the pilot will be advised of the location of the
Missed Approach Point (MAP) prescribed for the procedure
and the aircraft’s position each mile on fi nal from the runway,
airport or heliport or MAP, as appropriate.
If requested by the pilot, recommended altitudes will be
issued at each mile, based on the descent gradient established
for the procedure, down to the last mile that is at or above
the MDA. Normally, navigational guidance will be provided
until the aircraft reaches the MAP.
Radar service is automatically terminated at the completion
of a radar approach.
No-Gyro Approach is available to a pilot under radar control
who experiences circumstances wherein the directional gyro or
other stabilized compass is inoperative or inaccurate. When this
occurs, the pilot should so advise ATC and request a no-gyro
vector or approach. The pilot of an aircraft not equipped with a
directional gyro or other stabilized compass who desires radar
handling may also request a no-gyro vector or approach. The
pilot should make all turns at standard rate and should execute
the turn immediately upon receipt of instructions. For example,
“TURN RIGHT,” “STOP TURN.” When a surveillance or
precision approach is made, the pilot will be advised after the
aircraft has been turned onto fi nal approach to make turns at
half standard rate.
Radar Monitoring of Instrument Approaches
PAR facilities operated by the FAA and the military services
at some joint-use (civil and military) and military installations
monitor aircraft on instrument approaches and issue radar
advisories to the pilot when weather is below VFR minimums
(1,000 and 3), at night, or when requested by a pilot. This
service is provided only when the PAR Final Approach
Course coincides with the fi nal approach of the navigational
aid and only during the operational hours of the PAR. The
radar advisories serve only as a secondary aid since the pilot
has selected the navigational aid as the primary aid for the
approach.
Prior to starting fi nal approach, the pilot will be advised of
the frequency on which the advisories will be transmitted.
If, for any reason, radar advisories cannot be furnished, the
pilot will be so advised.
Advisory information, derived from radar observations,
includes information on:
1. Passing the fi nal approach fi x inbound (nonprecision
approach) or passing the outer marker or fi x used
in lieu of the outer marker inbound (precision
approach).
2. Trend advisories with respect to elevation and/or
azimuth radar position and movement will be
provided.
3. If, after repeated advisories, the aircraft proceeds
outside the PAR safety limit or if a radical deviation is
observed, the pilot will be advised to execute a missed
approach unless the prescribed visual reference with
the surface is established.
Radar service is automatically terminated upon completion
of the approach.
Timed Approaches From a Holding Fix
Timed approaches from a holding fi x are conducted when
many aircraft are waiting for an approach clearance. Although
the controller will not specifi cally state “timed approaches
are in progress,” the assigning of a time to depart the FAF
inbound (nonprecision approach), or the outer marker or
fi x used in lieu of the outer marker inbound (precision
approach), indicates that timed approach procedures are
being utilized.
10-19
Figure 10-11. ILS RWY 7 Troy, AL.
10-20
In lieu of holding, the controller may use radar vectors to the
fi nal approach course to establish a distance between aircraft
that will ensure the appropriate time sequence between the
FAF and outer marker, or fi x used in lieu of the outer marker
and the airport. Each pilot in the approach sequence will
be given advance notice of the time they should leave the
holding point on approach to the airport. When a time to
leave the holding point is received, the pilot should adjust
the fl ight path in order to leave the fi x as closely as possible
to the designated time.
Timed approaches may be conducted when the following
conditions are met:
1. A control tower is in operation at the airport where
the approaches are conducted.
2. Direct communications are maintained between the
pilot and the Center or approach controller until the
pilot is instructed to contact the tower.
3. If more than one missed approach procedure is
available, none require a course reversal.
4. If only one missed approach procedure is available,
the following conditions are met:
a) Course reversal is not required; and
b) Reported ceiling and visibility are equal to or
greater than the highest prescribed circling
minimums for the IAP.
5. When cleared for the approach, pilots should not
execute a procedure turn.
Approaches to Parallel Runways
Procedures permit ILS instrument approach operations to dual
or triple parallel runway confi gurations. A parallel approach
is an ATC procedure that permits parallel ILS approach to
airports with parallel runways separated by at least 2,500
feet between centerlines. Wherever parallel approaches
are in progress, pilots are informed that approaches to both
runways are in use.
Simultaneous approaches are permitted to runways:
1. With centerlines separated by 4,300 to 9,000 feet;
2. That are equipped with fi nal monitor controllers;
3. That require radar monitoring to ensure separation
between aircraft on the adjacent parallel approach
course.
The approach procedure chart will include the note
“simultaneous approaches authorized RWYS 14L and 14R,”
identifying the appropriate runways. When advised that
simultaneous parallel approaches are in progress, pilots must
advise approach control immediately of malfunctioning or
inoperative components.
Parallel approach operations demand heightened pilot
situational awareness. The close proximity of adjacent
aircraft conducting simultaneous parallel approaches
mandates strict compliance with all ATC clearances and
approach procedures. Pilots should pay particular attention
to the following approach chart information: name and
number of the approach, localizer frequency, inbound course,
glide slope intercept altitude, DA/DH, missed approach
instructions, special notes/procedures, and the assigned
runway location and proximity to adjacent runways. Pilots
also need to exercise strict radio discipline, which includes
continuous monitoring of communications and the avoidance
of lengthy, unnecessary radio transmissions.
Side-Step Maneuver
ATC may authorize a side-step maneuver to either one of
two parallel runways that are separated by 1,200 feet or less,
followed by a straight-in landing on the adjacent runway.
Aircraft executing a side-step maneuver will be cleared
for a specifi ed nonprecision approach and landing on the
adjacent parallel runway. For example, “Cleared ILS runway
7 left approach, side-step to runway 7 right.” The pilot is
expected to commence the side-step maneuver as soon as
possible after the runway or runway environment is in sight.
Landing minimums to the adjacent runway will be based on
nonprecision criteria and therefore higher than the precision
minimums to the primary runway, but will normally be lower
than the published circling minimums.
Circling Approaches
Landing minimums listed on the approach chart under
“CIRCLING” apply when it is necessary to circle the airport,
maneuver for landing, or when no straight-in minimums are
specifi ed on the approach chart.
The circling minimums published on the instrument approach
chart provide a minimum of 300 feet of obstacle clearance in
the circling area. During a circling approach,
the pilot should maintain visual contact with the runway of
intended landing and fl y no lower than the circling minimums
until positioned to make a fi nal descent for a landing. It is
important to remember that circling minimums are only
minimums. If the ceiling allows it, fl y at an altitude that
more nearly approximates VFR traffi c pattern altitude. This
will make any maneuvering safer and bring the view of the
landing runway into a more normal perspective.
Figure 10-13 shows patterns that can be used for circling
approaches. Pattern “A” can be fl own when the fi nal approach
10-21
Figure 10-12. Circling Approach Area Radii.
Figure 10-13. Circling Approaches.
course intersects the runway centerline at less than a 90°
angle, and the runway is in sight early enough to establish a
base leg. If the runway becomes visible too late to fl y pattern
“A,” circle as shown in “B.” Fly pattern “C” if it is desirable
to land opposite the direction of the fi nal approach, and the
runway is sighted in time for a turn to downwind leg. If the
runway is sighted too late for a turn to downwind, fl y pattern
“D.” Regardless of the pattern fl own, the pilot must maneuver
the aircraft to remain within the designated circling area.
Refer to section A (“Terms and Landing Minima Data”) in
the front of each TPP for a description of circling approach
categories.
The criteria for determining the pattern to be fl own are
based on personal fl ying capabilities and knowledge of the
performance characteristics of the aircraft. In each instance,
the pilot must consider all factors: airport design, ceiling and
visibility, wind direction and velocity, fi nal approach course
alignment, distance from the fi nal approach fi x to the runway,
and ATC instructions.
IAP Minimums
Pilots may not operate an aircraft at any airport below
the authorized MDA or continue an approach below the
authorized DA/DH unless:
1. The aircraft is continuously in a position from which
a descent to a landing on the intended runway can
be made at a normal descent rate using normal
maneuvers;
2. The fl ight visibility is not less than that prescribed for
the approach procedure being used; and
3. At least one of the following visual references for
the intended runway is visible and identifi able to the
pilot:
a) Approach light system
b) Threshold
c) Threshold markings
d) Threshold lights
e) Runway end identifi er lights (REIL)
f) Visual approach slope indicator (VASI)
g) Touchdown zone or touchdown zone markings
h) Touchdown zone lights
i) Runway or runway markings
j) Runway lights
Missed Approaches
A missed approach procedure is formulated for each
published instrument approach and allows the pilot to return
to the airway structure while remaining clear of obstacles.
The procedure is shown on the approach chart in text and
graphic form. Since the execution of a missed approach
occurs when the fl ight deck workload is at a maximum, the
10-22
procedure should be studied and mastered before beginning
the approach.
When a missed approach procedure is initiated, a climb pitch
attitude should be established while setting climb power.
Confi gure the aircraft for climb, turn to the appropriate
heading, advise ATC that a missed approach is being
executed, and request further clearances.
If the missed approach is initiated prior to reaching the
missed approach point (MAP), unless otherwise cleared by
ATC, continue to fl y the IAP as specifi ed on the approach
chart. Fly to the MAP at or above the MDA or DA/DH before
beginning a turn.
If visual reference is lost while circling-to-land from an
instrument approach, execute the appropriate missed
approach procedure. Make the initial climbing turn toward
the landing runway and then maneuver to intercept and fl y
the missed approach course.
Pilots should immediately execute the missed approach
procedure:
1. Whenever the requirements for operating below DA/
DH or MDA are not met when the aircraft is below
MDA, or upon arrival at the MAP and at any time
after that until touchdown;
2. Whenever an identifi able part of the airport is not visible
to the pilot during a circling maneuver at or above MDA;
or
3. When so directed by ATC.
Landing
According to 14 CFR part 91, no pilot may land when the fl ight
visibility is less than the visibility prescribed in the standard
IAP being used. ATC will provide the pilot with the current
visibility reports appropriate to the runway in use. This may be
in the form of prevailing visibility, runway visual value (RVV),
or runway visual range (RVR). However, only the pilot can
determine if the fl ight visibility meets the landing requirements
indicated on the approach chart. If the fl ight visibility meets
the minimum prescribed for the approach, then the approach
may be continued to a landing. If the fl ight visibility is less than
that prescribed for the approach, then the pilot must execute a
missed approach, regardless of the reported visibility.
The landing minimums published on IAP charts are based on
full operation of all components and visual aids associated
with the instrument approach chart being used. Higher
minimums are required with inoperative components or
visual aids. For example, if the ALSF-1 approach lighting
system were inoperative, the visibility minimums for an ILS
would need to be increased by one-quarter mile. If more
than one component is inoperative, each minimum is raised
to the highest minimum required by any single component
that is inoperative. ILS glide slope inoperative minimums
are published on instrument approach charts as localizer
minimums. Consult the “Inoperative Components or Visual
Aids Table” (printed on the inside front cover of each TPP),
for a complete description of the effect of inoperative
components on approach minimums.
Instrument Weather Flying
Flying Experience
The more experience a pilot has in VFR and IFR fl ight,
the more profi cient a pilot becomes. VFR experience can
be gained by flying in terminal areas with high traffic
activity. This type of fl ying forces the pilot to polish the
skill of dividing his or her attention between aircraft control,
navigation, communications, and other fl ight deck duties.
IFR experience can be gained through night fl ying which
also promotes both instrument profi ciency and confi dence.
The progression from fl ying at night under clear, moonlit
conditions to fl ying at night without moonlight, natural
horizon, or familiar landmarks teaches a pilot to trust the
aircraft instruments with minimal dependence upon what
can be seen outside the aircraft. It is a pilot’s decision to
proceed with an IFR fl ight or to wait for more acceptable
weather conditions.
Recency of Experience
Currency as an instrument pilot is an equally important
consideration. No person may act as pilot in command of an
aircraft under IFR or in weather conditions less than VFR
minimums unless he or she has met the requirements of part
91. Remember, these are minimum requirements.
Airborne Equipment and Ground Facilities
Regulations specify minimum equipment for fi ling an IFR
fl ight plan. It is the pilot’s responsibility to determine the
adequacy of the aircraft and navigation/communication
(NAV/COM) equipment for the proposed IFR flight.
Performance limitations, accessories, and general condition
of the equipment are directly related to the weather, route,
altitude, and ground facilities pertinent to the fl ight, as well
as to the fl ight deck workload.
Weather Conditions
In addition to the weather conditions that might affect a
VFR fl ight, an IFR pilot must consider the effects of other
weather phenomena (e.g., thunderstorms, turbulence, icing,
and visibility).
10-23
Figure 10-14. Maintaining an instrument scan in severe turbulence can be diffi cult.
Turbulence
Infl ight turbulence can range from occasional light bumps
to extreme airspeed and altitude variations that make aircraft
control diffi cult. To reduce the risk factors associated with
turbulence, pilots must learn methods of avoidance, as
well as piloting techniques for dealing with an inadvertent
encounter.
Turbulence avoidance begins with a thorough prefl ight weather
briefi ng. Many reports and forecasts are available to assist
the pilot in determining areas of potential turbulence. These
include the Severe Weather Warning (WW), SIGMET (WS),
Convective SIGMET (WST), AIRMET (WA), Severe Weather
Outlook (AC), Center Weather Advisory (CWA), Area Forecast
(FA), and Pilot Reports (UA or PIREPs). Since thunderstorms
are always indicative of turbulence, areas of known and forecast
thunderstorm activity will always be of interest to the pilot. In
addition, clear air turbulence (CAT) associated with jet streams,
strong winds over rough terrain, and fast moving cold fronts are
good indicators of turbulence.
Pilots should be alert while in fl ight for the signposts of
turbulence. For example, clouds with vertical development
such as cumulus, towering cumulus, and cumulonimbus are
indicators of atmospheric instability and possible turbulence.
Standing lenticular clouds lack vertical development but
indicate strong mountain wave turbulence. While en route,
pilots can monitor hazardous inflight weather advisory
service (HIWAS) broadcast for updated weather advisories,
or contact the nearest AFSS or En Route Flight Advisory
Service (EFAS) for the latest turbulence-related PIREPs.
To avoid turbulence associated with strong thunderstorms,
circumnavigate cells by at least 20 miles. Turbulence may
also be present in the clear air above a thunderstorm. To
avoid this, fl y at least 1,000 feet above the top for every 10
knots of wind at that level, or fl y around the storm. Finally,
do not underestimate the turbulence beneath a thunderstorm.
Never attempt to fl y under a thunderstorm. The possible
results of turbulence and wind shear under the storm could
be disastrous.
When moderate to severe turbulence is encountered, aircraft
control is diffi cult, and a great deal of concentration is
required to maintain an instrument scan. Pilots
should immediately reduce power and slow the aircraft to
the recommended turbulence penetration speed as described
in the POH/AFM. To minimize the load factor imposed on
the aircraft, the wings should be kept level and the aircraft’s
pitch attitude should be held constant. The aircraft is allowed
to fl uctuate up and down, because maneuvering to maintain
a constant altitude only increases the stress on the aircraft.
If necessary, the pilot should advise ATC of the fl uctuations
and request a block altitude clearance. In addition, the power
should remain constant at a setting that will maintain the
recommended turbulence penetration airspeed.
10-24
Figure 10-15. Temperature Ranges for Ice Formation.
The best source of information on the location and intensity
of turbulence are PIREPs. Therefore, pilots are encouraged to
familiarize themselves with the turbulence reporting criteria
found in the AIM, which also describes the procedure for
volunteering PIREPs relating to turbulence.
Structural Icing
The very nature of flight in Instrument Meteorological
Conditions means operating in visible moisture such as clouds.
At the right temperatures, this moisture can freeze on the
aircraft, causing increased weight, degraded performance, and
unpredictable aerodynamic characteristics. Understanding,
avoidance, and early recognition followed by prompt action
are the keys to avoiding this potentially hazardous situation.
Structural icing refers to the accumulation of ice on the exterior
of the aircraft and is broken down into three classifi cations:
rime ice, clear ice, and mixed ice. For ice to form, there must
be moisture present in the air, and the air must be cooled to
a temperature of 0° C (32° F) or less. Aerodynamic cooling
can lower the surface temperature of an airfoil and cause ice
to form on the airframe even though the ambient temperature
is slightly above freezing.
Rime ice forms if the droplets are small and freeze immediately
when contacting the aircraft surface. This type of ice usually
forms on areas such as the leading edges of wings or struts.
It has a somewhat rough-looking appearance and a milkywhite
color.
Clear ice is usually formed from larger water droplets or
freezing rain that can spread over a surface. This is the most
dangerous type of ice since it is clear, hard to see, and can
change the shape of the airfoil.
Mixed ice is a mixture of clear ice and rime ice. It has the
bad characteristics of both types and can form rapidly. Ice
particles become embedded in clear ice, building a very rough
accumulation. The table in Figure 10-15 lists the temperatures
at which the various types of ice will form.
Structural icing is a condition that can only get worse.
Therefore, during an inadvertent icing encounter, it is
important the pilot act to prevent additional ice accumulation.
Regardless of the level of anti-ice or deice protection offered
by the aircraft, the fi rst course of action should be to leave
the area of visible moisture. This might mean descending
to an altitude below the cloud bases, climbing to an altitude
that is above the cloud tops, or turning to a different course.
If this is not possible, then the pilot must move to an altitude
where the temperature is above freezing. Pilots should report
icing conditions to ATC and request new routing or altitude
if icing will be a hazard. Refer to the AIM for information
on reporting icing intensities.
Fog
Instrument pilots must learn to anticipate conditions leading
to the formation of fog and take appropriate action early in
the progress of the fl ight. Before a fl ight, close examination
of current and forecast weather should alert the pilot to the
possibility of fog formation. When fog is a consideration,
pilots should plan adequate fuel reserves and alternate
landing sites. En route, the pilot must stay alert for fog
formation through weather updates from EFAS, ATIS, and
ASOS/AWOS sites.
Two conditions will lead to the formation of fog. Either the
air is cooled to saturation, or suffi cient moisture is added
to the air until saturation occurs. In either case, fog can
form when the temperature/dewpoint spread is 5° or less.
Pilots planning to arrive at their destination near dusk with
decreasing temperatures should be particularly concerned
about the possibility of fog formation.
Volcanic Ash
Volcanic eruptions create volcanic ash clouds containing
an abrasive dust that poses a serious safety threat to fl ight
operations. Adding to the danger is the fact that these ash
clouds are not easily discernible from ordinary clouds when
encountered at some distance from the volcanic eruption.
When an aircraft enters a volcanic ash cloud, dust particles
and smoke may become evident in the cabin, often along with
the odor of an electrical fi re. Inside the volcanic ash cloud,
the aircraft may also experience lightning and St. Elmo’s fi re
on the windscreen. The abrasive nature of the volcanic ash
can pit the windscreens, thus reducing or eliminating forward
visibility. The pitot-static system may become clogged,
causing instrument failure. Severe engine damage is probable
in both piston and jet-powered aircraft.
Every effort must be made to avoid volcanic ash. Since
volcanic ash clouds are carried by the wind, pilots should plan
their fl ights to remain upwind of the ash-producing volcano.
Visual detection and airborne radar are not considered
a reliable means of avoiding volcanic ash clouds. Pilots
witnessing volcanic eruptions or encountering volcanic
ash should immediately pass this information along in
the form of a pilot report. The National Weather Service
10-25
Figure 10-16. A thunderstorm packs just about every weather hazard
known to aviation into one vicious bundle.
monitors volcanic eruptions and estimates ash trajectories.
This information is passed along to pilots in the form of
SIGMETs.
As for many other hazards to fl ight, the best source of
volcanic information comes from PIREPs. Pilots who witness
a volcanic eruption or encounter volcanic ash in flight
should immediately inform the nearest agency. Volcanic
Ash Forecast Transport and Dispersion (VAFTAD) charts
are also available; these depict volcanic ash cloud locations
in the atmosphere following an eruption, and also forecast
dispersion of the ash concentrations over 6- and 12-hour time
intervals. See AC 00-45, Aviation Weather Services.
Thunderstorms
A thunderstorm packs just about every weather hazard known
to aviation into one vicious bundle. Turbulence, hail, rain,
snow, lightning, sustained updrafts and downdrafts, and icing
conditions are all present in thunderstorms. Do not take off in
the face of an approaching thunderstorm or fl y an aircraft that is
not equipped with thunderstorm detection in clouds or at night
in areas of suspected thunderstorm activity.
There is no useful correlation between the external visual
appearance of thunderstorms and the severity or amount of
turbulence or hail within them. All thunderstorms should be
considered hazardous, and thunderstorms with tops above
35,000 feet should be considered extremely hazardous.
Weather radar, airborne or ground based, will normally
refl ect the areas of moderate to heavy precipitation (radar
does not detect turbulence). The frequency and severity of
turbulence generally increases with the radar refl ectivity
closely associated with the areas of highest liquid water
content of the storm. A fl ight path through an area of strong
or very strong radar echoes separated by 20 to 30 miles or
less may not be considered free of severe turbulence.
The probability of lightning strikes occurring to aircraft is
greatest when operating at altitudes where temperatures are
between -5 ° C and +5 ° C. In addition, an aircraft fl ying in the
clear air near a thunderstorm is also susceptible to lightning
strikes. Thunderstorm avoidance is always the best policy.
Wind Shear
Wind shear can be defi ned as a change in wind speed and/or
wind direction in a short distance. It can exist in a horizontal
or vertical direction and occasionally in both. Wind shear can
occur at all levels of the atmosphere but is of greatest concern
during takeoffs and landings. It is typically associated
with thunderstorms and low-level temperature inversions;
however, the jet stream and weather fronts are also sources
of wind shear.
As Figure 10-17 illustrates, while an aircraft is on an
instrument approach, a shear from a tailwind to a headwind
causes the airspeed to increase and the nose to pitch up with
a corresponding balloon above the glide path. A shear from
a headwind to a tailwind has the opposite effect, and the
aircraft will sink below the glide path.
A headwind shear followed by a tailwind/downdraft shear is
particularly dangerous because the pilot has reduced power
and lowered the nose in response to the headwind shear. This
leaves the aircraft in a nose-low, power-low confi guration
when the tailwind shear occurs, which makes recovery more
diffi cult, particularly near the ground. This type of wind
shear scenario is likely while making an approach in the
face of an oncoming thunderstorm. Pilots should be alert for
indications of wind shear early in the approach phase and be
ready to initiate a missed approach at the fi rst indication. It
may be impossible to recover from a wind shear encounter
at low altitude.
To inform pilots of hazardous wind shear activity, some
airports have installed a Low-Level Wind Shear Alert
System (LLWAS) consisting of a centerfi eld wind indicator
and several surrounding boundary-wind indicators. With
10-26
Figure 10-17. Glide slope Deviations Due to Wind Shear Encounter.
this system, controllers are alerted of wind discrepancies
(an indicator of wind shear possibility) and provide this
information to pilots. A typical wind shear alert issued to a
pilot would be:
“Runway 27 arrival, wind shear alert, 20 knot loss 3
mile fi nal, threshold wind 200 at 15”
In plain language, the controller is advising aircraft arriving
on runway 27 that at about 3 miles out they can expect a
wind shear condition that will decrease their airspeed by 20
knots and possibly encounter turbulence. Additionally, the
airport surface winds for landing runway 27 are reported as
200° at 15 knots.
Pilots encountering wind shear are encouraged to pass along
pilot reports. Refer to AIM for additional information on
wind shear PIREPs.
VFR-On-Top
Pilots on IFR flight plans operating in VFR weather
conditions may request VFR-on-top in lieu of an assigned
altitude. This permits them to select an altitude or fl ight level
of their choice (subject to any ATC restrictions).
Pilots desiring to climb through a cloud, haze, smoke, or
other meteorological formation and then either cancel their
IFR fl ight plan or operate VFR-on-top may request a climb
to VFR-on-top. The ATC authorization will contain a top
report (or a statement that no top report is available) and a
request to report upon reaching VFR-on-top. Additionally,
the ATC authorization may contain a clearance limit, routing,
and an alternative clearance if VFR-on-top is not reached by
a specifi ed altitude.
A pilot on an IFR fl ight plan, operating in VFR conditions,
may request to climb/descend in VFR conditions. When
operating in VFR conditions with an ATC authorization to
“maintain VFR-on-top/maintain VFR conditions,” pilots on
IFR fl ight plans must:
1. Fly at the appropriate VFR altitude as prescribed in 14
CFR part 91.
2. Comply with the VFR visibility and distance-fromcloud
criteria in 14 CFR part 91.
3. Comply with instrument fl ight rules applicable to this
fl ight (minimum IFR altitudes, position reporting, radio
communications, course to be fl own, adherence to ATC
clearance, etc.).
Pilots operating on a VFR-on-top clearance should advise
ATC before any altitude change to ensure the exchange of
accurate traffi c information.
ATC authorization to “maintain VFR-on-top” is not intended
to restrict pilots to operating only above an obscuring
meteorological formation (layer). Rather, it permits operation
above, below, between layers, or in areas where there is no
meteorological obstruction. It is imperative pilots understand,
however, that clearance to operate “VFR-on-top/VFR
conditions” does not imply cancellation of the IFR fl ight
plan.
Pilots operating VFR-on-top/VFR conditions may receive
traffi c information from ATC on other pertinent IFR or
VFR aircraft. However, when operating in VFR weather
conditions, it is the pilot’s responsibility to be vigilant to see
and avoid other aircraft.
This clearance must be requested by the pilot on an IFR fl ight
plan. VFR-on-top is not permitted in certain areas, such as
Class A airspace. Consequently, IFR fl ights operating VFRon-
top must avoid such airspace.
10-27
VFR Over-The-Top
VFR over-the-top must not be confused with VFR-ontop.
VFR-on-top is an IFR clearance that allows the pilot
to fl y VFR altitudes. VFR over-the-top is strictly a VFR
operation in which the pilot maintains VFR cloud clearance
requirements while operating on top of an undercast layer.
This situation might occur when the departure airport and the
destination airport are reporting clear conditions, but a low
overcast layer is present in between. The pilot could conduct
a VFR departure, fl y over the top of the undercast in VFR
conditions, then complete a VFR descent and landing at the
destination. VFR cloud clearance requirements would be
maintained at all times, and an IFR clearance would not be
required for any part of the fl ight.
Conducting an IFR Flight
To illustrate some of the concepts introduced in this chapter,
follow along on a typical IFR fl ight from the Birmingham
International Airport (BHM), Birmingham, Alabama to
Gulfport-Biloxi International Airport (GPT), Gulfport,
Mississippi. For this trip, a Cessna 182
with a call sign of N1230A will be fl own. The aircraft is
equipped with dual navigation and communication radios, a
transponder, and a GPS system approved for IFR en route,
terminal, and approach operations.
Prefl ight
The success of the flight depends largely upon the
thoroughness of the prefl ight planning. The evening before
the fl ight, pay close attention to the weather forecast and
begin planning the fl ight.
The Weather Channel indicates a large, low-pressure system
has settled in over the Midwest, pulling moisture up from
the Gulf of Mexico and causing low ceilings and visibility
with little chance for improvement over the next couple of
days. To begin planning, gather all the necessary charts and
materials, and verify everything is current. This includes en
route charts, approach charts, DPs, STAR charts, the GPS
database, as well as an A/FD, some navigation logs, and the
aircraft’s POH/AFM. The charts cover both the departure
and arrival airports and any contingency airports that will
be needed if the fl ight cannot be completed as planned. This
is also a good time for the pilot to consider recent fl ight
experience, pilot profi ciency, fi tness, and personal weather
minimums to fl y this particular fl ight.
Check the A/FD to become familiar with the departure and
arrival airport, and check for any preferred routing between
BHM and GPT. Next, review the approach charts and any
DP or STAR that pertains to the fl ight. Finally, review the en
route charts for potential routing, paying close attention to the
minimum en route and obstacle clearance altitudes.
After this review, select the best option. For this fl ight, the
Birmingham Three Departure to Brookwood
VORTAC, V 209 to Kewanee VORTAC, direct to Gulfport
using GPS would be a logical route. An altitude of 4,000 feet
meets all the regulatory requirements and falls well within
the performance capabilities of the aircraft.
Next, call 1-800-WX-BRIEF to obtain an outlook-type
weather briefing for the proposed flight. This provides
forecast conditions for departure and arrival airports, as well
as the en route portion of the fl ight including forecast winds
aloft. This also is a good opportunity to check the available
NOTAMs.
The weather briefer confi rms the predictions of the weather
channel giving forecast conditions that are at or near
minimum landing minimums at both BHM and GPT for
the proposed departure time. The briefer provides NOTAM
information for GPT indicating that the localizer to runway
32 is scheduled to be out of service and that runway 18/36 is
closed until further notice. Also check for temporary fl ight
restrictions (TFRs) along the proposed route.
After receiving a weather briefi ng, continue fl ight planning
and begin to transfer some preliminary information onto
the navigation log, listing each fi x along the route and the
distances, frequencies, and altitudes. Consolidating this
information onto an organized navigation log will keep the
workload to a minimum during the fl ight.
Next, obtain a standard weather briefi ng online for the
proposed route. A check of current conditions indicates
low IFR conditions at both the departure airport and the
destination, with visibility of one-quarter mile:
SURFACE WEATHER OBSERVATIONS
METAR KBHM 111155Z VRB04KT ¼ SM FG –RA VV004
06/05 A2994 RMK A02 SLP140
METAR KGPT 111156Z 24003KT ¼ SM FG OVC001 08/07
A2962 RMK A02 SLP033
The small temperature/dewpoint spread is causing the low
visibility and ceilings. Conditions should improve later in
the day as temperatures increase. A check of the terminal
forecast confi rms this theory:
TERMINAL FORECASTS
TAF KBHM 111156Z 111212 VRB04KT ¼ SM FG VV004
TEMPO1316 ¾ SM OVC004
FM1600 VRB05KT 2SM BR OVC007 TEMPO 1720 3SM
DZ BKN009
10-28
Figure 10-18. Route Planning.
10-29
FM2000 22008KT 3SM –RA OVC015 TEMP 2205 3SM
–RA OVC025 FM0500 23013KT P6SM OVC025
FM0800 23013KT P6SM BKN030 PROB40 1012 2SM BR
OVC030
TAF KGPT 111153Z 111212 24004KT ¼ SM FG OVC001
BECMG 1317 3SM BR 0VC004
FM1700 24010KT 4SM –RA OVC006 FM0400 24010 5SM
SCT080 TEMPO 0612 P6SM SKC
In addition to the terminal forecast, the area forecast also
indicates gradual improvement along the route. Since the
terminal forecast only provides information for a 5-mile
radius around a terminal area, checking the area forecast
provides a better understanding of the overall weather picture
along the route, as well as potential hazards:
SYNOPSIS AND VFR CLOUDS/WEATHER FORECASTS
SYNOPSIS… AREA OF LOW PRESSURE CNTD OV AL
RMNG GENLY STNRY BRNGNG MSTR AND WD SPRD
IFR TO E TN. ALF…LOW PRES TROF ACRS CNTR PTN
OF THE DFW FA WILL GDLY MOV EWD DURG PD.
NRN LA, AR, NRN MS
SWLY WND THRUT THE PD. 16Z CIG OVC006. SCT
–SHRA. OTLK… IFR SRN ½ … CIG SCT – BKN015
TOPS TO FL250 SWLY WND THRUT THE PD. 17Z AGL
BKN040. OTLK…MVFR CIG VIS.
LA MS CSTL WTRS
CIG OVC001 – OVC006. TOPS TO FL240. VIS ¼ - ¾ SM
FG. SWLY WND. 16Z CIG OVC010 VIS 2 SM BR. OCNL
VIS 3-5SM –RN BR OVC009. OTLK…MVFR CIG VIS.
FL
CIG BKN020 TOPS TO FL180. VIS 1–3 SM BR. SWLY
WND. 18Z BRK030. OTLK…MVFR CIG.
At this time, there are no SIGMETs or PIREPs reported.
However, there are several AIRMETs, one for IFR
conditions, one for turbulence that covers the entire route,
and another for icing conditions which covers an area just
north of the route:
WAUS44 KKCI 111150
DFWS WA 0111150
AIRMET SIERRA FOR IFR VALID UNTIL 111800
AIRMET IFR...OK TX LA AR MS AL FL
TS IMPLY SEV OR GTR TURB SEV ICE LLWS AND
IFR CONDS.
NON MSL HGHTS DENOTED BY AGL OR CIG.
A recheck of NOTAMs for Gulfport confirms that the
localizer to runway 32 is out of service until further notice
and runway 18/36 is closed. If runway 6 is planned for the
departure, confi rm that the climb restriction for the departure
can be met.
GPT 12/006 GPT LOC OS UFN
GPT 12/008 GPT MIRL RWY 18/36 OS UFN
Since the weather is substantially better to the east, Pensacola
Regional Airport is a good alternate with current conditions
and a forecast of marginal VFR.
METAR KPNS 111150Z 21010Z 3SM BKN014 OVC025
09/03 A2973
TAF KPNS 111152Z 111212 22010KT 3 SM BR OVC020
BECMG 1317 4 SM BR OVC025
FM1700 23010KT 4SM –RA OVC030
FM 0400 25014KT 5SM OVC050 TEMPO1612 P6SM
OVC080
If weather minimums are below a pilot’s personal minimums,
a delay in departure to wait for improved conditions is
a good decision. This time can be used to complete the
navigation log which is the next step in planning an IFR
fl ight.
Use the POH/AFM to compute a true airspeed, cruise power
setting, and fuel burn based on the forecast temperatures
aloft and cruising pressure altitude. Also, compute weightand-
balance information and determine takeoff and landing
distances. There will be a crosswind if weather conditions
require a straight-in landing on runway 14 at GPT. Therefore,
compute the landing distance assuming a 10-knot crosswind
and determine if the runway length is adequate to allow
landing. Determine the estimated fl ight time and fuel burn
using the winds aloft forecast and considering Pensacola
Regional Airport as an alternate airport. With full tanks, the
fl ight can be made nonstop with adequate fuel for fl ight to
the destination, alternate, and the reserve requirement.
Next, check the surface analysis chart which shows where the
pressure systems will be found. The weather depiction chart
shows areas of IFR conditions and can be used to fi nd areas
10-30
Figure 10-19. Navigation Log.
of improving conditions. These charts provide information
a pilot will need should a diversion to VFR conditions be
required. For this fl ight, the radar depicts precipitation along
the route, and the latest satellite photo confi rms what the
weather depiction chart showed.
When the navigation log is fi nished, complete the fl ight plan
in preparation for fi ling with fl ight service.
Call an AFSS for an updated weather briefi ng, Birmingham
INTL airport is now reporting 700 overcast with 3 miles
visibility, and Gulfport-Biloxi is now 400 overcast with 2
miles visibility. The alternate, Pensacola Regional Airport,
continues to report adequate weather conditions with 2,000
overcast and 3 miles visibility in light rain.
10-31
Figure 10-20. Flight Plan Form.
Several pilot reports have been submitted for light icing
conditions; however, all the reports are north of the route
of fl ight and correspond to the AIRMET that was issued
earlier. No pilot reports have included cloud tops, but the
area forecast predicted cloud tops to fl ight level 240. Since
the weather conditions appear to be improving, a fl ight plan
can be fi led using the completed form.
Analyze the latest weather minimums to determine if they
exceed personal minimums. With the absence of icing
reported along the route and steadily rising temperatures,
structural icing should not be a problem. Make a note to
do an operational check of the pitot heat during prefl ight
and to take evasive action immediately should even light
icing conditions be encountered in fl ight. This may require
returning to BHM or landing at an intermediate spot before
reaching GPT. The go/no-go decision will be constantly
reevaluated during the fl ight.
Once at the airport, conduct a thorough prefl ight inspection.
A quick check of the logbooks indicates all airworthiness
requirements have been met to conduct this IFR flight
including an altimeter, static, and transponder test within
the preceding 24 calendar months. In addition, a log on
the clipboard indicates the VOR system has been checked
within the preceding 30 days. Turn on the master switch and
pitot heat, and quickly check the heating element before it
becomes too hot. Then, complete the rest of the walk-around
procedure. Since this will be a fl ight in actual IFR conditions,
place special emphasis on IFR equipment during the walkaround,
including the alternator belt and antennas. After
completing the prefl ight, organize charts, pencils, paper, and
navigation log in the fl ight deck for quick, easy access. This
is also the time to enter the planned fl ight into the GPS.
Departure
After starting the engine, tune in ATIS and copy the
information to the navigation log. The conditions remain the
same as the updated weather briefi ng with the ceiling at 700
overcast, and visibility at 3 miles. Call clearance delivery to
receive a clearance:
“Clearance Delivery, Cessna 1230A IFR to Gulfport
Biloxi with information Kilo, ready to copy.”
“Cessna 1230A is cleared to Gulfport-Biloxi via the
Birmingham Three Departure, Brookwood, Victor
209 Kewanee then direct Mindo, Gulfport. Climb and
maintain 4,000. Squawk 0321.”
10-32
Read back the clearance and review the DP. Although a
departure frequency was not given in the clearance, note that
on the DP, the departure control frequency is listed as 123.8
for the southern sector. Since a departure from runway 24
is anticipated, note the instruction to climb to 2,100 prior
to turning. After tuning in the appropriate frequencies and
setting up navigation equipment for the departure routing,
contact ground control (noting that this is IFR) and receive
the following clearance:
“Cessna 1230A taxi to runway 24 via taxiway
Mike.”
Read back the clearance and aircraft call sign. After a review
of the taxi instructions on the airport diagram, begin to taxi
and check the fl ight instruments for proper indications.
Hold short of runway 24 and complete the before takeoff
checklist and engine run-up. Advise the tower when ready
for takeoff. The tower gives the following clearance:
“Cessna 30A cleared for takeoff runway 24.
Caution wake turbulence from 737 departing to the
northwest.”
Taxi into position. Note the time off on the navigation log,
verify that the heading indicator and magnetic compass are
in agreement, the transponder is in the ALT position, all the
necessary lights, equipment, and pitot heat are on. Start the
takeoff roll. To avoid the 737’s wake turbulence, make note
of its lift off point and take off prior to that point.
En Route
After departure, climb straight ahead to 2,100 feet as directed
by the Birmingham Three Departure. While continuing a
climb to the assigned altitude of 4,000 feet, the following
instructions are received from the tower:
“Cessna 30A contact Departure.”
Acknowledge the clearance and contact departure on the
frequency designated by the DP. State the present altitude
so the departure controller can check the encoded altitude
against indicated altitude:
“Birmingham Departure Cessna 1230A climbing
through 2,700 heading 240.”
Departure replies:
“Cessna 30A proceed direct to Brookwood and resume
own navigation. Contact Atlanta Center on 134.05.”
Acknowledge the clearance, contact Atlanta Center and
proceed direct to Brookwood VORTAC, using the IFRapproved
GPS equipment. En route to Kewanee, VORTAC
Atlanta Center issues the following instructions:
“Cessna 1230A contact Memphis Center on
125.975.”
Acknowledge the instructions and contact Memphis Center
with aircraft ID and present altitude. Memphis Center
acknowledges contact:
“Cessna 1230A, Meridian altimeter is 29.87. Traffi c
at your 2 o’clock and 6 miles is a King Air at 5,000
climbing to 12,000.”
Even when on an IFR fl ight plan, pilots are still responsible
for seeing and avoiding other aircraft. Acknowledge the call
from Memphis Center and inform them of negative contact
with traffi c due to IMC.
“Roger, altimeter setting 29.87. Cessna 1230A is in
IMC negative contact with traffi c.”
Continue the fl ight, and at each fi x note the arrival time on
the navigation log to monitor progress.
To get an update of the weather at the destination and issue
a pilot report, contact the FSS servicing the area. To fi nd
the nearest AFSS, locate a nearby VOR and check above
the VOR information box for a frequency. In this case, the
nearest VOR is Kewanee VORTAC which lists a receiveonly
frequency of 122.1 for Greenwood FSS. Request a
frequency change from Memphis and then attempt to contact
Greenwood on 122.1 while listening over the Kewanee
VORTAC frequency of 113.8:
“Greenwood Radio Cessna 1230A receiving on
frequency 113.8, over.”
“Cessna 30A, this is Greenwood, go ahead.”
“Greenwood Radio, Cessna 30A is currently 30 miles
south of the Kewanee VORTAC at 4,000 feet en
route to Gulfport. Requesting an update of en route
conditions and current weather at GPT, as well as
PNS.”
“Cessna 30A, Greenwood Radio, current weather at
Gulfport is 400 overcast with 3 miles visibility in light
rain. The winds are from 140 at 7 and the altimeter
is 29.86. Weather across your route is generally IFR
in light rain with ceilings ranging from 300 to 1,000
overcast with visibilities between 1 and 3 miles.
Pensacola weather is much better with ceilings now
at 2,500 and visibility 6 miles. Checking current
NOTAMs at GPT shows the localizer out of service
and runway 18/36 closed.”
10-33
“Roger, Cessna 30A copies the weather. I have a
PIREP when you are ready to copy.”
“Cessna 30A go ahead with your PIREP.”
“Cessna 30A is a Cessna 182 located on the Kewanee
195° radial at 30 miles level at 4,000 feet. I am
currently in IMC conditions with a smooth ride.
Outside air temperature is plus 1° Celsius. Negative
icing.”
“Cessna 30A thank you for the PIREP.”
With the weather check and PIREP complete, return to
Memphis Center:
“Memphis Center, Cessna 1230A is back on your
frequency.”
“Cessna 1230A, Memphis Center, roger, contact
Houston Center now on frequency 126.8.”
“Roger, contact Houston Center frequency 126.8,
Cessna 1230A.”
“Houston Center, Cessna 1230A level at 4,000
feet.”
“Cessna 30A, Houston Center area altimeter 29.88.”
Arrival
40 miles north of Gulfport, tune in ATIS on number two
communication radio. The report reveals there has been no
change in the weather and ATIS is advertising ILS runway
14 as the active approach.
Houston Center completes a hand off to Gulfport approach
control with instructions to contact approach:
“Gulfport Approach, Cessna 1230A level 4,000 feet
with information TANGO. Request GPS Runway 14
approach.”
“Cessna 30A, Gulfport Approach, descend and
maintain 3,000 feet.”
“Descend to 3,000, Cessna 30A.”
Begin a descent to 3,000 and confi gure your navigation
radios for the approach. The GPS will automatically change
from the en route mode to the terminal mode. This change
will affect the sensitivity of the CDI. Tune in the VORTAC
frequency of 109.0 on the number one navigation radio, and
set in the fi nal approach course of 133° on the OBS. This
setup will help with situational awareness should the GPS
lose signal.
“Cessna 30A your position is 7 miles from MINDO,
maintain 3,000 feet until MINDO, cleared for the GPS
runway 14 approach.”
Read back the clearance and concentrate on fl ying the aircraft.
At MINDO descend to 2,000 as depicted on the approach
chart. At BROWA turn to the fi nal approach course of
133°. Just outside the Final Approach Way Point (FAWP)
AVYUM, the GPS will change to the approach mode and
the CDI will become even more sensitive. Gulfport approach
control issues instructions to contact Gulfport tower:
“Cessna 30A contact Tower on 123.7.”
“123.7, Cessna 30A.”
“Tower, Cessna 1230A outside AVYUM on the GPS
runway 14.”
“Cessna 30A Gulfport Tower, the ceiling is now 600
overcast and the visibility is 4 miles.”
“Cleared to land runway 14, Cessna 30A.”
Continue the approach, complete the appropriate checklists,
cross AVYUM, and begin the fi nal descent. At 700 feet MSL
visual contact with the airport is possible. Slow the aircraft
and confi gure it to allow a normal descent to landing. As
touch down is completed, Gulfport Tower gives further
instructions:
“Cessna 30A turn left at taxiway Bravo and contact
ground on 120.4.”
“Roger, Cessna 30A.”
Taxi clear of the runway and complete the appropriate
checklists. The Tower will automatically cancel the IFR
fl ight plan.
10-34
11-1
Introduction
Changing weather conditions, air traffi c control (ATC), the
aircraft, and the pilot are all variables that make instrument
fl ying an unpredictable and challenging operation. The safety
of the fl ight depends upon the pilot’s ability to manage these
variables while maintaining positive aircraft control and
adequate situational awareness. This chapter discusses the
recognition and suggested remedies for such abnormal and
emergency events related to unforecasted, adverse weather;
aircraft system malfunctions; communication/navigation
system malfunctions; and loss of situational awareness.
Emergency
Operations
Chapter 11
11-2
Unforecast Adverse Weather
Inadvertent Thunderstorm Encounter
A pilot should avoid fl ying through a thunderstorm of any
intensity. However, certain conditions may be present that
could lead to an inadvertent thunderstorm encounter. For
example, fl ying in areas where thunderstorms are embedded
in large cloud masses may make thunderstorm avoidance
diffi cult, even when the aircraft is equipped with thunderstorm
detection equipment. Therefore, pilots must be prepared to
deal with an inadvertent thunderstorm penetration. At the
very least, a thunderstorm encounter subjects the aircraft to
turbulence that could be severe. The pilot and passengers
should tighten seat belts and shoulder harnesses and secure
any loose items in the cabin.
As with any emergency, the fi rst order of business during
an inadvertent thunderstorm encounter must be to fl y the
aircraft. The pilot workload is heavy; therefore, increased
concentration is necessary to maintain an instrument scan.
If a pilot inadvertently enters a thunderstorm, it is better to
maintain a course straight through the thunderstorm rather
than turning around. A straight course minimizes the amount
of time in the thunderstorm and turning maneuvers only
increase structural stress on the aircraft.
Reduce power to a setting that maintains a speed at the
recommended turbulence penetration speed as described in the
Pilot’s Operating Handbook/Airplane Flight Manual (POH/
AFM), and try to minimize additional power adjustments.
Concentrate on maintaining a level attitude while allowing
airspeed and altitude to fl uctuate. Similarly, if using the
autopilot, disengage the altitude hold and speed hold modes,
as they only increase the aircraft’s maneuvering—thereby
increasing structural stress.
During a thunderstorm encounter, the potential for icing
also exists. As soon as possible, turn on anti-icing/deicing
equipment and carburetor heat, if equipped. Icing can be
rapid at any altitude and may lead to power failure and/or
loss of airspeed indication.
Lightning is also present in a thunderstorm and can
temporarily blind a pilot. To reduce this risk, turn up fl ight
deck lights to the highest intensity, concentrate on the fl ight
instruments, and resist the urge to look outside.
Inadvertent Icing Encounter
Because icing is unpredictable in nature, pilots may fi nd
themselves in icing conditions even though they have done
everything practicable to avoid it. In order to stay alert to this
possibility while operating in visible moisture, pilots should
monitor the outside air temperature (OAT).
The effects of ice on aircraft are cumulative—thrust is
reduced, drag increases, lift lessens, and weight increases.
The results are an increase in stall speed and a deterioration
of aircraft performance. In extreme cases, two to three inches
of ice can form on the leading edge of the airfoil in less than
5 minutes. It takes only 1/2 inch of ice to reduce the lifting
power of some aircraft by 50 percent and increases the
frictional drag by an equal percentage.
A pilot can expect icing when fl ying in visible precipitation,
such as rain or cloud droplets, and the temperature is
between +02 and -10° Celsius. When icing is detected, a
pilot should do one of two things, particularly if the aircraft
is not equipped with deicing equipment: leave the area of
precipitation or go to an altitude where the temperature is
above freezing. This “warmer” altitude may not always be
a lower altitude. Proper prefl ight action includes obtaining
information on the freezing level and the above-freezing
levels in precipitation areas.
If neither option is available, consider an immediate landing
at the nearest suitable airport. Even if the aircraft is equipped
with anti-icing/deicing equipment, it is not designed to allow
aircraft to operate indefi nitely in icing conditions. Antiicing/
deicing equipment gives a pilot more time to get out of
the icing conditions. Report icing to ATC and request new
routing or altitude. Be sure to report the type of aircraft, and
use the following terms when reporting icing to ATC:
1. Trace. Ice becomes perceptible. Rate of accumulation
is slightly greater than sublimation. Deicing/anti-icing
equipment is not utilized unless encountered for an
extended period of time (over 1 hour).
2. Light. The rate of accumulation may create a problem
if fl ight is prolonged in this environment (over 1
hour). Occasional use of deicing/anti-icing equipment
removes/prevents accumulation. It does not present a
problem if deicing/anti-icing equipment is used.
3. Moderate. The rate of accumulation is such that even
short encounters become potentially hazardous and
use of deicing/anti-icing equipment or fl ight diversion
is necessary.
4. Severe. The rate of accumulation is such that deicing/
anti-icing equipment fails to reduce or control the
hazard. Immediate fl ight diversion is necessary.
Early ice detection is critical and is particularly diffi cult during
night fl ight. Use a fl ashlight to check for ice accumulation on
the wings. At the fi rst indication of ice accumulation, take
action to get out of the icing conditions. Refer to the POH/
AFM for the proper use of anti-icing/deicing equipment.
11-3
Figure 11-2. One example of a static wick installed on aircraft
control surface to bleed off static charges built up during fl ight.
This will prevent static buildup and St. Elmo’s fi re by allowing
the static electricity to dissipate harmlessly.
Figure 11-1. St. Elmo’s Fire is harmless but may affect both communication and navigation radios, especially the lower frequencies
such as those used on the ADF.
Precipitation Static
Precipitation static, often referred to as P-static, occurs
when accumulated static electricity is discharged from the
extremities of the aircraft. This discharge has the potential
to create problems for the instrument pilot. These problems
range from the serious, such as erroneous magnetic compass
readings and the complete loss of very high frequency (VHF)
communications to the annoyance of high-pitched audio
squealing and St. Elmo’s fi re.
Precipitation static is caused when an aircraft encounters
airborne particles during flight (e.g., rain or snow),
and develops a negative charge. It can also result from
atmospheric electric fi elds in thunderstorm clouds. When
a signifi cant negative voltage level is reached, the aircraft
discharges it, which can create electrical disturbances. This
electrical discharge builds with time as the aircraft fl ies in
precipitation. It is usually encountered in rain, but snow can
cause the same effect. As the static buildup increases, the
effectiveness of both communication and navigation systems
decreases to the point of potential unusability.
To reduce the problems associated with P-static, the pilot
should ensure the aircraft’s static wicks are properly maintained
and accounted for. Broken or missing static wicks should be
replaced before an instrument fl ight.
Aircraft System Malfunctions
Preventing aircraft system malfunctions that might lead
to an infl ight emergency begins with a thorough prefl ight
11-4
Figure 11-3. G1000 PFD display in normal mode and in the reversionary mode activated upon system failure.
inspection. In addition to those items normally checked
prior to a visual fl ight rules (VFR) fl ight, pilots intending to
fl y under instrument fl ight rules (IFR) should pay particular
attention to the alternator belt, antennas, static wicks, antiicing/
deicing equipment, pitot tube, and static ports.
During taxi, verify the operation and accuracy of all fl ight
instruments. In addition, during the run-up, verify that the
operation of the pneumatic system(s) is within acceptable
parameters. It is critical that all systems are determined to be
operational before departing into IFR conditions.
Electronic Flight Display Malfunction
When a pilot becomes familiar and comfortable with the
new electronic displays, he or she also tends to become more
reliant on the system. The system then becomes a primary
source of navigation and data acquisition instead of the
supplementary source of data as initially intended.
Complete reliance on the moving map for navigation becomes
a problem during a failure of one, more, or all of the fl ight
display screens. Under these conditions, the systems revert to
a composite mode (called reversionary), which eliminates the
moving map display and combines the PFD with the engine
indicating system. If a pilot has relied on the
display for navigation information and situational awareness,
he or she lacks any concept of critical data such as the aircraft’s
position, the nearest airport, or proximity to other aircraft.
The electronic fl ight display is a supplementary source of
navigation data and does not replace en route charts. To
maintain situational awareness, a pilot must follow the fl ight
on the en route chart while monitoring the PFD. It is important
for the pilot to know the location of the closest airport as
well as surrounding traffi c relative to the location of his or
her aircraft. This information becomes critical should the
electronic fl ight display fail.
For the pilot who utilizes the electronic database as a
substitute for the Airport Facilities Directory, screen failure
or loss of electrical power can mean the pilot is no longer
able to access airport information. Once the pilot loses the
ability to call up airport information, aeronautical decisionmaking
is compromised.
Alternator/Generator Failure
Depending upon the aircraft being fl own, an alternator failure
is indicated in different ways. Some aircraft use an ammeter
11-5
Figure 11-4. Ammeter (left) and Loadmeter (right).
Figure 11-5. Double Rocker Switch Seen on Many Aircraft.
that indicates the state of charge or discharge of the battery.
A positive indication on the ammeter indicates
a charge condition; a negative indication reveals a discharge
condition. Other aircraft use a load meter to indicate the load
being carried by the alternator.
Sometimes an indicator light is also installed in the aircraft to
alert the pilot to an alternator failure. On some aircraft such
as the Cessna 172, the light is located on the lower left side
making it diffi cult to see its illumination if charts are open
Ensure that these safety indicators are visible during fl ight.
When a loss of the electrical charging system is experienced,
the pilot has approximately 40 minutes of battery life
remaining before the system fails entirely. The time
mentioned is an approximation and should not be relied upon
as specifi c to all aircraft. In addition, the battery charge that
exists in a battery may not be full, altering the time available
before electrical exhaustion occurs. At no time should a pilot
consider continuing a fl ight once the electrical charging
system has failed. Land at the nearest suitable airport.
Techniques for Electrical Usage
Master Battery Switch
One technique for conserving the main battery charge is
to fl y the aircraft to the airport of intended landing while
operating with minimal power. If a two-position battery
master/alternator rocker switch is installed, it
can be utilized to isolate the main battery from the electrical
system and conserve power.
Operating on the Main Battery
While en route to the airport of intended landing, reduce the
electrical load as much as practical. Turn off all unnecessary
electrical items such as duplicate radios, non-essential
lighting, etc. If unable to turn off radios, lights, etc. manually,
consider pulling circuit breakers to isolate those pieces of
equipment from the electrical system. Maximum time of
useful voltage may be between 30 and 40 minutes and is
infl uenced by many factors, which degrade the useful time.
Loss of Alternator/Generator for Electronic Flight
Instrumentation
With the increase in electrical components being installed
in modern technically advanced aircraft, the power supply
and the charging system need increased attention and
understanding. Traditional round dial aircraft do not rely
as heavily on electrical power for the primary six-pack
instrumentation. Modern electronic fl ight displays utilize the
electrical system to power the AHRS, ADC, engine indicating
system (EIS), etc. A loss of an alternator or generator was
considered an abnormality in traditionally equipped aircraft;
11-6
Figure 11-6. Note the double rocker switch and the standby battery
switch in this aircraft. The standby battery must be armed to work
correctly; arming should be done prior to departure.
however, a failure of this magnitude is considered an
emergency in technically advanced aircraft.
Due to the increased demand for electrical power, it is
necessary for manufacturers to install a standby battery in
conjunction with the primary battery. The standby battery is
held in reserve and kept charged in case of a failure of the
charging system and a subsequent exhaustion of the main
battery. The standby battery is brought online when the main
battery voltage is depleted to a specifi c value, approximately
19 volts. Generally, the standby battery switch must be in the
ARM position for this to occur but pilots should refer to the
aircraft fl ight manual for specifi cs on an aircraft’s electrical
system. The standby battery powers the essential bus and
allows the primary fl ight display (PFD) to be utilized.
The essential bus usually powers the following
components:
1. AHRS (Attitude and Heading Reference System)
2. ADC (Air Data Computer)
3. PFD (Primary Flight Display)
4. Navigation Radio #1
5. Communication Radio #1
6. Standby Indicator Light
Techniques for Electrical Usage
Standby Battery
One technique for conserving the main battery charge is
to fl y the aircraft to the airport of intended landing while
using the standby battery. A two-position battery master/
alternator rocker switch is installed on most aircraft with
electronic fl ight displays, which can be utilized to isolate
the main battery from the electrical system. By switching the
MASTER side off, the battery is taken offl ine and the standby
battery comes online to power the essential bus. However,
the standby battery switch must be in the ARM position for
this to occur. Utilization of the standby battery
fi rst reserves the main battery for use when approaching to
land. With this technique, electrical power may be available
for the use of fl aps, gear, lights, etc. Do not rely on any power
to be available after the standby battery has exhausted itself.
Once the charging system has failed, fl ight with a powered
electrical system is not guaranteed.
Operating on the Main Battery
While en route to the airport of intended landing, reduce the
electrical load as much as practical. Turn off all unnecessary
electrical items such as duplicate radios, non-essential
lighting, etc. If unable to turn off radios, lights, etc., manually,
consider pulling circuit breakers to isolate those pieces of
equipment from the electrical system. Keep in mind that
once the standby battery has exhausted its charge, the fl ight
deck may become very dark depending on what time of
day the failure occurs. The priority during this emergency
situation is landing the aircraft as soon as possible without
jeopardizing safety.
A standby attitude indicator, altimeter, airspeed indicator
(ASI) and magnetic compass are installed in each aircraft
for use when the PFD instrumentation is unavailable.
These would be the only instruments left
available to the pilot. Navigation would be limited to pilotage
and dead reckoning unless a hand-held transceiver with a
GPS/navigation function is onboard.
Once an alternator failure has been detected, the pilot must
reduce the electrical load on the battery and land as soon as
practical. Depending upon the electrical load and condition
of the battery, there may be suffi cient power available for
45 minutes of fl ight—or for only a matter of minutes. Pilots
should also know which systems on the aircraft are electric and
those that continue to operate without electrical power. Pilots
can attempt to troubleshoot alternator failure by following
the established alternator failure procedure published in the
POH/AFM. If the alternator cannot be reset, advise ATC of
the situation and inform them of the impending electrical
failure.
Analog Instrument Failure
A warning indicator or an inconsistency between indications
on the attitude indicator and the supporting performance
11-7
Figure 11-7. Emergency Instrumentation Available to the Pilot on Electronic Flight Instrumented Aircraft.
instruments usually identifi es system or instrument failure.
Aircraft control must be maintained while identifying the
failed component(s). Expedite the cross-check and include
all flight instruments. The problem may be individual
instrument failure or a system failure affecting multiple
instruments.
One method of identification involves an immediate
comparison of the attitude indicator with the rate-of-turn
indicator and vertical speed indicator (VSI). Along with
providing pitch-and-bank information, this technique
compares the static system with the suction or pressure system
and the electrical system. Identify the failed component(s)
and use the remaining functional instruments to maintain
aircraft control.
Attempt to restore the inoperative component(s) by checking
the appropriate power source, changing to a backup or
alternate system, and resetting the instrument if possible.
Covering the failed instrument(s) may enhance a pilot’s
ability to maintain aircraft control and navigate the aircraft.
Usually, the next step is to advise ATC of the problem and,
if necessary, declare an emergency before the situation
deteriorates beyond the pilot’s ability to recover.
Pneumatic System Failure
One possible cause of instrument failure is a loss of the
suction or pressure source. This pressure or suction is
supplied by a vacuum pump mechanically driven off the
engine. Occasionally these pumps fail, leaving the pilot with
inoperative attitude and heading indicators.
Figure 11-8 illustrates inoperative vacuum driven attitude
and heading indicators which can fail progressively. As the
gyroscopes slow down they may wander, which, if connected
to the autopilot and/or fl ight director, can cause incorrect
movement or erroneous indications. In Figure 11-8, the
aircraft is actually level and at 2,000 feet MSL. It is not in
a turn to the left which the pilot may misinterpret if he or
she fails to see the off or failed fl ags. If that occurs, the pilot
may transform a normally benign situation into a hazardous
situation. Again, good decision-making by the pilot only
occurs after a careful analysis of systems.
Many small aircraft are not equipped with a warning system
for vacuum failure; therefore, the pilot should monitor the
system’s vacuum/pressure gauge. This can be a hazardous
situation with the potential to lead the unsuspecting pilot into
a dangerous unusual attitude which would require a partial
panel recovery. It is important that pilots practice instrument
fl ight without reference to the attitude and heading indicators
in preparation for such a failure.
Pitot/Static System Failure
A pitot or static system failure can also cause erratic and
unreliable instrument indications. When a static system
11-8
Figure 11-8. Vacuum Failure.
problem occurs, it affects the ASI, altimeter, and the VSI.
In most aircraft, provisions have been made for the pilot to
select an alternate static source. Check the POH/AFM for
the location and operation of the alternate static source. In
the absence of an alternate static source, in an unpressurized
aircraft, the pilot could break the glass on the VSI. The VSI
is not required for instrument fl ight, and breaking the glass
provides the altimeter and the ASI a source of static pressure.
This procedure could cause additional instrument errors.
Communication/Navigation System
Malfunction
Avionics equipment has become very reliable, and the
likelihood of a complete communications failure is remote.
However, each IFR fl ight should be planned and executed in
anticipation of a two-way radio failure. At any given point
during a fl ight, the pilot must know exactly what route to fl y,
what altitude to fl y, and when to continue beyond a clearance
limit. Title 14 of the Code of Federal Regulations (14 CFR)
part 91 describes the procedures to be followed in case of a
two-way radio communications failure. If operating in VFR
conditions at the time of the failure, the pilot should continue
the fl ight under VFR and land as soon as practicable. If the
failure occurs in IFR conditions, or if VFR conditions cannot
be maintained, the pilot must continue the fl ight:
1. Along the route assigned in the last ATC clearance
received;
2. If being radar vectored, by the direct route from the
point of radio failure to the fi x, route, or airway specifi ed
in the vector clearance;
3. In the absence of an assigned route, by the route
that ATC has advised may be expected in a further
clearance; or
4. In the absence of an assigned route or a route that ATC
has advised may be expected in a further clearance,
by the route fi led in the fl ight plan.
The pilot should maintain the highest of the following
altitudes or fl ight levels for the route segment being fl own:
1. The altitude or fl ight level assigned in the last ATC
clearance received;
2. The minimum altitude (converted, if appropriate, to
minimum fl ight level as prescribed in part 91 for IFR
operations); or
3. The altitude or fl ight level ATC has advised may be
expected in a further clearance.
In addition to route and altitude, the pilot must also plan the
progress of the fl ight to leave the clearance limit.
1. When the clearance limit is a fi x from which an
approach begins, commence descent or descent
and approach as close as possible to the expectfurther-
clearance time if one has been received. If an
expect-further-clearance time has not been received,
commence descent or descent and approach as close as
possible to the estimated time of arrival as calculated
from the fi led or amended (with ATC) estimated time
en route.
11-9
Figure 11-9. The default soft key menu that is displayed on the PFD contains a “NRST” (Nearest Airport) soft key. Pressing this soft
key opens a text box which displays the nearest 25 airports.
Nearest Airports Using the PFD
With the advancements in electronic databases, diverting to
alternate airports has become easier. Simply by pressing a soft
key on the PFD, pilots can access information for up to 25 of
the nearest airports that meet the criteria set in the systems
confi guration page. Pilots are able to specify
what airports are acceptable for their aircraft requirements
based on landing surface and length of runway.
When the text box opens, the fl ashing cursor is located over
the nearest airport that meets the criteria set in the auxiliary
setup page as shown in Figure 11-10. Scrolling through the
25 airports is accomplished by turning the outer FMS knob,
which is located on the lower right corner of the display
screen. Turning the FMS knob clockwise moves the blinking
cursor to the next closest airport. By continuing to turn the
knob, the pilot is able to scroll through all 25 nearest airports.
Each airport box contains the information illustrated in
Figure 11-11, which the pilot can utilize to determine which
airport best suits their individual needs.
Additional Information for a Specifi c Airport
In addition to the information that is presented on the fi rst
screen, the pilot can view additional information as shown in
Figure 11-12 by highlighting the airport identifi er and then
pressing the enter key.
2. If the clearance limit is not a fi x from which an
approach begins, leave the clearance limit at the
expect-further-clearance time if one has been received.
If no expect-further-clearance time has been received,
leave the clearance limit upon arrival over it, and
proceed to a fi x from which an approach begins and
commence descent or descent and approach as close as
possible to the estimated time of arrival as calculated
from the fi led or amended (with ATC) estimated time
en route.
While following these procedures, set the transponder to
code 7600 and use all means possible to reestablish two-way
radio communication with ATC. This includes monitoring
navigational aids (NAVAIDs), attempting radio contact with
other aircraft, and attempting contact with a nearby automated
fl ight service station (AFSS).
GPS Nearest Airport Function
Procedures for accessing the nearest airport information
vary by the type of display installed in an aircraft. Pilots can
obtain information relative to the nearest airport by using the
PFD, MFD, or the nearest function on the GPS receiver. The
following examples are based on a popular system. Pilots
should become familiar with the operational characteristics
of the equipment to be used.
11-10
Figure 11-11. Information shown on the nearest airport page.
Figure 11-12. Information shown on the additional information
page that will aid the pilot in making a more informed decision
about which airport to choose when diverting.
Figure 11-10. An enlargement of the box shown in the lower right
of Figure 11-9. Note that KGNV would be fl ashing.
From this menu or the previous default nearest airport screen,
the pilot is able to activate the Direct-To function, which
provides a direct GPS course to the airport. In addition,
the pilot can auto-tune communication frequencies by
highlighting the appropriate frequency and then pressing
the enter key. The frequency is placed in the stand-by box
of either COM1 or COM2, whichever frequency has the
cyan box around it.
Nearest Airports Using the MFD
A second way to determine the nearest airport is by
referencing the NRST Page Group located on the MFD. This
method provides additional information to the pilot; however,
it may require additional steps to view.
Navigating the MFD Page Groups
Most display systems are designed for ease of navigation
through the different screens on the MFD. Notice the
various page groups in the lower right-hand corner of the
MFD screen. Navigation through these four page groups
is accomplished by turning the outer FMS knob clockwise.
Within each page group are specifi c pages that provide
additional information pertaining to that specifi c group. Once
the desired page group and page is selected, the MFD remains
in that confi guration until the page is changed or the CLR
button is depressed for more than 2 seconds. Holding the CLR
button returns the display to the default moving map page.
Nearest Airport Page Group
The nearest airport page contains specifi c areas of interest
for the airport selected. The pilot is furnished
information regarding runways, frequencies, and types of
approaches available.
Nearest Airports Page Soft Keys
Figure 11-16 illustrates four specifi c soft keys that allow
the pilot to access independent windows of the airport page.
Selection of each of these windows can also be accomplished
by utilizing the MENU hard key.
The soft keys and functions are as follows: Scroll through
each section with the cursor, then press enter to accept the
selection.
1. APT. Allows the user access to scroll through the
25 nearest airports. The white arrow indicates which
airport is selected. The INFORMATION window
is slaved to the white arrow. The INFORMATION
window decodes the airport identifi er. Scroll through
the 25 airports by turning the outer FMS knob.
11-11
Figure 11-13. The MFD is another means of viewing the nearest airports.
Figure 11-14. Page Groups. As the FMS outer knob is rotated, the
current page group is indicated by highlighting the specifi c group
indicator. Notice that the MAP page group is highlighted.
2. RNWY. Moves the cursor into the Runways section
and allows the user to scroll through the available
runways at a specific airport that is selected in
conjunction with the APT soft key. A green arrow
indicates additional runways to view.
3. FREQ. Moves the cursor into the Frequencies section
and allows the pilot to highlight and auto-tune the
frequency into the selected standby box.
4. APR. Moves the cursor into the Approach section and
allows the pilot to review approaches and load them
into the fl ight plan. When the APR soft key is selected,
an additional soft key appears. The LD APR (Load
Approach) soft key must be pressed once the desired
instrument approach procedure has been highlighted.
Once the soft key is pressed, the screen changes to the
PROC Page Group. From this page the pilot is able to
choose the desired approach, the transition, and choose
the option to activate the approach or just load it into
the fl ight plan.
Situational Awareness
Situational awareness (SA) is not simply a mental picture of
aircraft location; rather, it is an overall assessment of each
element of the environment and how it affects a fl ight. On one
end of the SA spectrum is a pilot who is knowledgeable of
every aspect of the fl ight; consequently, this pilot’s decisionmaking
is proactive. With good SA, this pilot is able to make
decisions well ahead of time and evaluate several different
options. On the other end of the SA spectrum is a pilot who
is missing important pieces of the puzzle: “I knew exactly
where I was when I ran out of fuel.” Consequently, this
pilot’s decision-making is reactive. With poor SA, a pilot
11-12
Figure 11-15. The page group of nearest airports has been selected.
lacks a vision of future events and is forced to make decisions
quickly, often with limited options.
During a typical IFR fl ight, a pilot operates at varying levels
of SA. For example, a pilot may be cruising to his or her
destination with a high level of SA when ATC issues an
unexpected standard terminal arrival route (STAR). Since the
pilot was not expecting the STAR and is not familiar with it,
SA is lowered. However, after becoming familiar with the
STAR and resuming normal navigation, the pilot returns to
a higher level of SA.
Factors that reduce SA include: distractions, unusual or
unexpected events, complacency, high workload, unfamiliar
situations, and inoperative equipment. In some situations, a
loss of SA may be beyond a pilot’s control. For example, a
pneumatic system failure and associated loss of the attitude
and heading indicators could cause a pilot to fi nd his or her
aircraft in an unusual attitude. In this situation, established
procedures must be used to regain SA.
Pilots should be alert to a loss of SA anytime they are in a
reactive mindset. To regain SA, reassess the situation and
seek additional information from other sources, such as the
navigation instruments or ATC.
Summary
Electronic fl ight displays have been dramatically improved
regarding how information is displayed and what information
is available to a pilot. With only the push of a button, a pilot
is able to access information that was traditionally contained
in multiple publications. (Electronic databases have replaced
paper manuals and reduced the clutter in the fl ight deck.)
Multi-Function Displays (MFD) are capable of displaying
moving maps that mirror sectional charts. These detailed
displays depict all airspace including permanent temporary
fl ight restrictions (TFRs).
In fact, MFDs have become so descriptive that many pilots
fall into the trap of relying solely on the moving maps for
navigation. In addition, pilots are drawing upon the database
to familiarize themselves with departure and destination
airport information.
Pilots are relying heavily on the electronic database for their
fl ight planning and have moved away from the traditional
method of cross-country fl ight planning. It is imperative
to understand that the electronic fl ight display adds to the
overall quality of the fl ight experience, but can also lead to
11-13
Figure 11-16. The four soft keys at the bottom of the MFD are airport (A), runway (B), frequency (C), and approach (D).
11-14
Figure 11-17. The Area Surrounding the Aircraft for Coverage
Using TIS.
Figure 11-18. A Typical Display on Aircraft MFD When Using TIS.
catastrophe if not utilized properly. At no time is the moving
map meant to substitute for a VFR sectional or Low Altitude
En Route chart.
Traffi c Avoidance
Electronic fl ight displays have the capability of displaying
transponder-equipped aircraft on the MFD as well as the
inset map on the PFD. However, due to the limitations of the
systems, not all traffi c is displayed. Some TIS units display
only eight intruding targets within the service volume. The
normal service volume has altitude limitations of 3,500 feet
below the aircraft to 3,500 feet above the aircraft. The lateral
limitation is 7 NM. Pilots unfamiliar with the
limitations of the system may rely on the aural warnings to
alert them to approaching traffi c.
In addition to an outside visual scan of traffi c, a pilot should
incorporate any Traffi c Information electronically displayed
such as TIS. This innovation in traffi c alerting reinforces and
adds synergy to the ability to see and avoid. However, it is
an aid and not a replacement for the responsibilities of the
pilot. Systems such as TIS provide a visual representation
of nearby traffi c and displays a symbol on the moving map
display with relative information about altitude, vertical
trends, and direction of fl ight.
11-15
It is important to remember that most systems display only a
specifi c maximum number of targets allowed. Therefore, it
does not mean that the targets displayed are the only aircraft
in the vicinity. The system displays only the closest aircraft.
In addition, the system does not display aircraft that are not
equipped with transponders. The display may not show any
aircraft; however, a Piper Cub with no transponder could be
fl ying in the area. TIS coverage can be sporadic and is not
available in some areas of the United States. Traffi c advisory
software is to be utilized only for increased situational
awareness and not the sole means of traffi c avoidance. There is
no substitute for a good visual scan of the surrounding sky.
11-16
A-1
The following shorthand system is recommended by the
Federal Aviation Administration (FAA). Applicants for the
instrument rating may use any shorthand system, in any
language, which ensures accurate compliance with air traffi c
control (ATC) instructions. No shorthand system is required
by regulation and no knowledge of shorthand is required for
the FAA Knowledge Test; however, because of the vital need
for reliable communication between the pilot and controller,
clearance information should be unmistakably clear.
The following symbols and contractions represent words
and phrases frequently used in clearances. Most are used
regularly by ATC personnel. By practicing this shorthand,
omitting the parenthetical words, you will be able to copy
long clearances as fast as they are read.
Example: CAF RH RV V18 40 SQ 0700 DPC 120.4
Cleared as fi led, maintain runway heading for radar vector
to Victor 18, climb to 4,000, squawk 0700, departure control
frequency is 120.4.
Words and Phrases Shorthand
Above ..........................................................................ABV
Above (Altitude, Hundreds of Feet) ............................... 70
Adjust speed to 250 knots ......................................... 250 K
Advise .........................................................................ADZ
After (Passing) ..................................................................<
Airway (Designation) ................................................... V26
Airport ..............................................................................A
Alternate Instructions ...................................................... ( )
Altitude 6,000–17,000 .............................................60-170
And ...................................................................................&
Approach ........................................................................AP
Approach Control ........................................................ APC
Area Navigation .......................................................RNAV
Arriving ..............................................................................
At.....................................................................................@
At or Above ....................................................................
At or Below ....................................................................
(ATC) Advises ...............................................................CA
(ATC) Clears or Cleared .................................................. C
(ATC) Requests .............................................................CR
Appendix A
Back Course ...................................................................BC
Bearing ...........................................................................BR
Before (Reaching, Passing) ...............................................>
Below ..........................................................................BLO
Below (Altitude, Hundreds of Feet) ................................ 70
Center .......................................................................... CTR
Clearance Void if Not Off By (Time) .............................v<
Cleared as Filed ........................................................... CAF
Cleared to Airport ............................................................A
Cleared to Climb/Descend at Pilot’s Discretion ............PD
Cleared to Cross ...............................................................X
Cleared to Depart From the Fix .......................................D
Cleared to the Fix ..............................................................F
Cleared to Hold and Instructions Issued ..........................H
Cleared to Land .................................................................L
Cleared to the Outer Marker ............................................O
Climb to (Altitude, Hundreds of Feet) ........................... 70
Contact Approach ..........................................................CT
Contact (Denver) Approach Control ............................ (den
Contact (Denver) Center ............................................(DEN
Course ..........................................................................CRS
Cross ................................................................................X
Cruise .............................................................................
Delay Indefi nite ............................................................ DLI
Depart (Direction, if Specifi ed) ................................ T ( )
Departure Control ....................................................... DPC
Descend To (Altitude, Hundreds of Feet) ...................... 70
Direct ..............................................................................DR
Direction (Bound)
Eastbound ................................................................... EB
Westbound .................................................................WB
Northbound .................................................................NB
Southbound ................................................................. SB
Inbound ........................................................................ IB
Outbound ....................................................................OB
DME Fix (Mile) ............................................................
Each ................................................................................EA
Enter Control Area .......................................................
Estimated Time of Arrival .......................................... ETA
Expect ............................................................................EX
Expect-Further-Clearance ............................................EFC
Clearance Shorthand
A-2
Fan Marker .................................................................... FM
Final ..................................................................................F
Final Approach ...............................................................FA
Flight Level .................................................................... FL
Flight Planned Route....................................................FPR
For Further Clearance ..................................................FFC
For Further Headings ...................................................FFH
From .............................................................................. FM
Ground ....................................................................... GND
GPS Approach .............................................................GPS
Heading ...................................................................... HDG
Hold (Direction) ..........................................................H-W
Holding Pattern ............................................................
ILS Approach ................................................................ ILS
Increase Speed 30 Knots ...........................................+30 K
Initial Approach .................................................................I
Instrument Departure Procedure ....................................DP
Intersection .................................................................... XN
Join or Intercept Airway/Jet Route/Track or Course ........
Left Turn After Takeoff ...................................................
Locator Outer Marker ................................................LOM
Magnetic ..........................................................................M
Maintain ........................................................................
Maintain VFR Conditions On Top ............................. VFR
Middle Compass Locator ..............................................ML
Middle Marker .............................................................MM
Missed Approach ..........................................................MA
Nondirectional Beacon Approach ...............................NDB
Out of (Leave) Control Area ........................................
Outer Marker .................................................................OM
Over (Station) ..............................................................OKC
On Course ......................................................................OC
Precision Approach Radar .......................................... PAR
Procedure Turn ............................................................... PT
Radar Vector ..................................................................RV
Radial (080° Radial) .................................................. 080R
Reduce Speed 20 Knots .............................................-20 K
Remain This Frequency ...............................................RTF
Remain Well to Left Side .............................................. LS
Remain Well to Right Side ............................................ RS
Report Crossing .............................................................RX
Report Departing ............................................................RD
Report Leaving ...............................................................RL
Report on Course .....................................................R-CRS
Report Over ....................................................................RO
Report Passing ............................................................... RP
Report Reaching .............................................................RR
Report Starting Procedure Turn .................................RSPT
Reverse Course ..............................................................RC
Right Turn After Takeoff .................................................
Runway Heading ............................................................RH
Runway (Number) .....................................................RY18
Squawk ...........................................................................SQ
Standby .....................................................................STBY
Straight-in Approach ........................................................SI
Surveillance Radar Approach ..................................... ASR
Takeoff (Direction) ...................................................T N
Tower ................................................................................Z
Turn Left ........................................................................ TL
Turn Right ......................................................................TR
Until ................................................................................... /
Until Advised (By) ........................................................ UA
Until Further Advised .................................................UFA
VFR Conditions On Top ..............................................OTP
Via ................................................................................VIA
Victor (Airway Number) .............................................. V14
Visual Approach ........................................................... VA
VOR ..............................................................................
VOR Approach ..............................................................VR
VORTAC ......................................................................
While in Control Area ..................................................
B-1
Introduction
Flight instructors may use this guide in the development of
lesson plans. The lessons are arranged in a logical learning
sequence and use the building-block technique. Each lesson
includes ground training appropriate to the fl ight portion of
the lesson. It is vitally important that the fl ight instructor brief
the student on the objective of the lesson and how it will be
accomplished. Debriefi ng the student’s performance is also
necessary to motivate further progress. To ensure steady
progress, student pilots should master the objective of each
lesson before advancing to the next lesson. Lessons should
be arranged to take advantage of each student’s knowledge
and skills.
Flight instructors must monitor progress closely during
training to guide student pilots in how to properly divide
their attention. The importance of this division of attention
or “cross-check” cannot be overemphasized. Cross-check and
proper instrument interpretation are essential components
of “attitude instrument fl ying” that enables student pilots to
accurately visualize the aircraft’s attitude at all times.
When possible, each lesson should incorporate radio
communications, basic navigation, and emergency procedures
so the student pilot is exposed to the entire IFR experience
with each fl ight. Cross-reference the Instrument Training
Lesson Guide with this handbook and the Instrument
Practical Test Standards for a comprehensive instrument
rating training program.
Lesson 1—Ground and fl ight evaluation
of student’s knowledge and performance
Aircraft systems
Aircraft performance
Prefl ight planning
Use of checklists
Basic fl ight maneuvers
Radio communications procedures
Navigation systems
Appendix B
Instrument Training Lesson Guide
Lesson 2—Prefl ight preparation and
fl ight by reference to instruments
Ground Training
Instrument system prefl ight procedures
Attitude instrument fl ying
Fundamental instrument skills
Instrument cross-check techniques
Flight Training
Aircraft and instrument prefl ight inspection
Use of checklists
Fundamental instrument skills
Basic fl ight maneuvers
Instrument approach (demonstrated)
Postfl ight procedures
Lesson 3—Flight instruments and human
factors
Ground Training
Human factors
Flight instruments and systems
Aircraft systems
Navigation instruments and systems
Flight Training
Aircraft and instrument prefl ight inspection
Radio communications
Checklist procedures
Attitude instrument fl ying
Fundamental instrument skills
Basic fl ight maneuvers
Spatial disorientation demonstration
Navigation systems
Postfl ight procedures
Lesson 4—Attitude instrument fl ying
Ground Training
Human factors
Flight instruments and systems
B-2
Aircraft systems
Navigation instruments and systems
Attitude instrument fl ying
Fundamental instrument skills
Basic fl ight maneuvers
Flight Training
Aircraft and instrument prefl ight inspection
Checklist procedures
Radio communications
Attitude instrument fl ying
Fundamental instrument skills
Basic fl ight maneuvers
Spatial disorientation
Navigation
Postfl ight procedures
Lesson 5—Aerodynamic factors and
basic fl ight maneuvers
Ground Training
Basic aerodynamic factors
Basic instrument fl ight patterns
Emergency procedures
Flight Training
Aircraft and instrument prefl ight inspection
Checklist procedures
Radio communications
Basic instrument fl ight patterns
Emergency procedures
Navigation
Postfl ight procedures
Lesson 6—Partial panel operations
Ground Training
ATC system
Flight instruments
Partial panel operations
Flight Training
Aircraft and instrument prefl ight inspection
Checklist procedures
Radio communications
Basic instrument fl ight patterns
Emergency procedures
Partial panel practice
Navigation
Postfl ight procedures
Lesson 7—Recovery from unusual
attitudes
Ground Training
Attitude instrument fl ying
ATC system
NAS overview
Flight Training
Prefl ight
Aircraft and instrument prefl ight inspection
Checklist procedures
Radio communications
Instrument takeoff
Navigation
Partial panel practice
Recovery from unusual attitudes
Postfl ight procedures
Lesson 8—Navigation systems
Ground Training
ATC clearances
Departure procedures
IFR en route charts
Flight Training
Aircraft and instrument prefl ight inspection
Checklist procedures
Radio communications
Intercepting and tracking
Holding
Postfl ight procedures
Lesson 9—Review and practice
Ground Training
Aerodynamic factors
Flight instruments and systems
Attitude instrument fl ying
Navigation systems
NAS
ATC
Emergency procedures
Flight Training
Aircraft and instrument prefl ight inspection
Checklist procedures
Radio communications
Review and practice as determined by the fl ight instructor
B-3
Instrument takeoff
Radio communications
Navigation systems
Emergency procedures
Postfl ight procedures
Lessons 10 through 19—Orientation,
intercepting, tracking, and holding using
each navigation system installed in the
aircraft
Ground Training
Prefl ight planning
Navigation systems
NAS
ATC
Emergencies
Flight Training
Aircraft and instrument prefl ight inspection
Checklist procedures
Radio communications
Departure procedures
En route navigation
Terminal operations
Partial panel operation
Instrument approach
Missed approach
Approach to a landing
Postfl ight procedures
Lessons 20 and 21—Cross-country
fl ights
Ground Training
Prefl ight planning
Aircraft performance
Navigation systems
NAS
ATC
Emergencies
Flight Training
Emergency procedures
Partial panel operation
Aircraft and instrument prefl ight inspection
Checklist procedures
Radio communications
Departure procedures
En route navigation
Terminal operations
Instrument approach
Missed approach
Approach to a landing
Postfl ight procedures
Lessons 22 and 23—Review and practice
Ground Training
Human factors
Aerodynamic factors
Flight instruments and systems
Attitude instrument fl ying
Basic fl ight maneuvers
Navigation systems
NAS
ATC
Emergency operations
Flight Training
Aircraft and instrument prefl ight inspection
Checklist procedures
Radio communications
Review and practice as determined by the fl ight instructor
Instrument takeoff
Partial panel operations
Unusual attitude recoveries
Radio communications
Navigation systems
Emergency procedures
Postfl ight procedures
Lessons 24 and subsequent—Practical
test preparation
Ground Training
Title 14 of the Code of Federal Regulations (14 CFR) parts
61, 71, 91, 95, and 97
Instrument Flying Handbook
Practical test standards
Administrative requirements
Equipment requirements
Applicant’s requirements
Flight Training
Review and practice until the student can consistently
perform all required tasks in accordance with the appropriate
practical test standards.
NOTE: It is the recommending instructor’s responsibility to
ensure that the applicant meets 14 CFR part 61 requirements
and is prepared for the practical test, including: training,
knowledge, experience, and the appropriate instructor
endorsements.
G-1
Absolute accuracy. The ability to determine present position
in space independently, and is most often used by pilots.
Absolute altitude. The actual distance between an aircraft
and the terrain over which it is fl ying.
Absolute pressure. Pressure measured from the reference
of zero pressure, or a vacuum.
A.C. Alternating current.
Acceleration error. A magnetic compass error apparent when
the aircraft accelerates while fl ying on an easterly or westerly
heading, causing the compass card to rotate toward North.
Accelerometer. A part of an inertial navigation system
(INS) that accurately measures the force of acceleration in
one direction.
ADF. See automatic direction fi nder.
ADI. See attitude director indicator.
ADM. See aeronautical decision-making.
ADS–B. See automatic dependent surveillance–broadcast.
Adverse yaw. A fl ight condition at the beginning of a turn in
which the nose of the aircraft starts to move in the direction
opposite the direction the turn is being made, caused by the
induced drag produced by the downward-defl ected aileron
holding back the wing as it begins to rise.
Aeronautical decision-making (ADM). A systematic
approach to the mental process used by pilots to consistently
determine the best course of action in response to a given
set of circumstances.
A/FD. See Airport/Facility Directory.
Glossary
Agonic line. An irregular imaginary line across the surface of
the Earth along which the magnetic and geographic poles are in
alignment, and along which there is no magnetic variation.
Aircraft approach category. A performance grouping of
aircraft based on a speed of 1.3 times the stall speed in the
landing confi guration at maximum gross landing weight.
Air data computer (ADC). An aircraft computer that
receives and processes pitot pressure, static pressure, and
temperature to calculate very precise altitude, indicated
airspeed, true airspeed, and air temperature.
AIRMET. Infl ight weather advisory issued as an amendment
to the area forecast, concerning weather phenomena of
operational interest to all aircraft and that is potentially
hazardous to aircraft with limited capability due to lack of
equipment, instrumentation, or pilot qualifi cations.
Airport diagram. The section of an instrument approach
procedure chart that shows a detailed diagram of the
airport. This diagram includes surface features and airport
confi guration information.
Airport/Facility Directory (A/FD). An FAA publication
containing information on all airports, communications,
and NAVAIDs.
Airport surface detection equipment (ASDE). Radar
equipment specifically designed to detect all principal
features and traffi c on the surface of an airport, presenting the
entire image on the control tower console; used to augment
visual observation by tower personnel of aircraft and/or
vehicular movements on runways and taxiways.
Airport surveillance radar (ASR). Approach control
radar used to detect and display an aircraft’s position in the
terminal area.
G-2
Airport surveillance radar approach. An instrument
approach in which ATC issues instructions for pilot
compliance based on aircraft position in relation to the fi nal
approach course and the distance from the end of the runway
as displayed on the controller’s radar scope.
Air route surveillance radar (ARSR). Air route traffi c
control center (ARTCC) radar used primarily to detect
and display an aircraft’s position while en route between
terminal areas.
Air route traffic control center (ARTCC). Provides ATC
service to aircraft operating on IFR flight plans within
controlled airspace and principally during the en route phase
of fl ight.
Airspeed indicator. A differential pressure gauge that
measures the dynamic pressure of the air through which the
aircraft is flying. Displays the craft’s airspeed, typically in
knots, to the pilot.
Air traffic control radar beacon system (ATCRBS).
Sometimes called secondary surveillance radar (SSR), which
utilizes a transponder in the aircraft. The ground equipment is
an interrogating unit, in which the beacon antenna is mounted
so it rotates with the surveillance antenna. The interrogating
unit transmits a coded pulse sequence that actuates the aircraft
transponder. The transponder answers the coded sequence by
transmitting a preselected coded sequence back to the ground
equipment, providing a strong return signal and positive
aircraft identification, as well as other special data.
Airway. An airway is based on a centerline that extends from
one navigation aid or intersection to another navigation aid
(or through several navigation aids or intersections); used
to establish a known route for en route procedures between
terminal areas.
Alert area. An area in which there is a high volume of pilot
training or an unusual type of aeronautical activity.
Almanac data. Information the global positioning system
(GPS) receiver can obtain from one satellite which describes
the approximate orbital positioning of all satellites in the
constellation. This information is necessary for the GPS
receiver to know what satellites to look for in the sky at a
given time.
ALS. See approach lighting system.
Alternate airport. An airport designated in an IFR fl ight
plan, providing a suitable destination if a landing at the
intended airport becomes inadvisable.
Alternate static source valve. A valve in the instrument static
air system that supplies reference air pressure to the altimeter,
airspeed indicator, and vertical speed indicator if the normal
static pickup should become clogged or iced over.
Altimeter setting. Station pressure (the barometric pressure
at the location the reading is taken) which has been corrected
for the height of the station above sea level.
AME. See aviation medical examiner.
Amendment status. The circulation date and revision
number of an instrument approach procedure, printed above
the procedure identifi cation.
Ammeter. An instrument installed in series with an electrical
load used to measure the amount of current fl owing through
the load.
Aneroid. The sensitive component in an altimeter or
barometer that measures the absolute pressure of the air.
It is a sealed, fl at capsule made of thin disks of corrugated
metal soldered together and evacuated by pumping all of
the air out of it.
Aneroid barometer. An instrument that measures the
absolute pressure of the atmosphere by balancing the weight
of the air above it against the spring action of the aneroid.
Angle of attack. The acute angle formed between the
chord line of an airfoil and the direction of the air striking
the airfoil.
Anti-ice. Preventing the accumulation of ice on an aircraft
structure via a system designed for that purpose.
Approach lighting system (ALS). Provides lights that will
penetrate the atmosphere far enough from touchdown to give
directional, distance, and glide path information for safe
transition from instrument to visual fl ight.
Area chart. Part of the low-altitude en route chart series,
this chart furnishes terminal data at a larger scale for
congested areas.
Area navigation (RNAV). Allows a pilot to fl y a selected
course to a predetermined point without the need to overfl y
ground-based navigation facilities, by using waypoints.
ARSR. See air route surveillance radar.
ARTCC. See air route traffi c control center.
G-3
ASDE. See airport surface detection equipment.
ASOS. See automated surface observing station.
ASR. See airport surveillance radar.
ATC. Air Traffi c Control.
ATCRBS. See air traffic control radar beacon system.
ATIS. See automatic terminal information service.
Atmospheric propagation delay. A bending of the
electromagnetic (EM) wave from the satellite that creates
an error in the GPS system.
Attitude and heading reference systems (AHRS). System
composed of three-axis sensors that provide heading, attitude,
and yaw information for aircraft. AHRS are designed to
replace traditional mechanical gyroscopic flight instruments
and provide superior reliability and accuracy.
Attitude director indicator (ADI). An aircraft attitude
indicator that incorporates fl ight command bars to provide
pitch and roll commands.
Attitude indicator. The foundation for all instrument fl ight,
this instrument refl ects the airplane’s attitude in relation to
the horizon.
Attitude instrument flying. Controlling the aircraft by
reference to the instruments rather than by outside visual
cues.
Autokinesis. Nighttime visual illusion that a stationary light
is moving, which becomes apparent after several seconds of
staring at the light.
Automated Weather Observing System (AWOS).
Automated weather reporting system consisting of various
sensors, a processor, a computer-generated voice subsystem,
and a transmitter to broadcast weather data.
Automated Surface Observing Station (ASOS). Weather
reporting system which provides surface observations every
minute via digitized voice broadcasts and printed reports.
Automatic dependent surveillance–broadcast (ADS-B). A
device used in aircraft that repeatedly broadcasts a message
that includes position (such as latitude, longitude, and
altitude), velocity, and possibly other information.
Automatic direction finder (ADF). Electronic navigation
equipment that operates in the low- and medium-frequency
bands. Used in conjunction with the ground-based
nondirectional beacon (NDB), the instrument displays the
number of degrees clockwise from the nose of the aircraft
to the station being received.
Automatic terminal information service (ATIS). The
continuous broadcast of recorded non-control information in
selected terminal areas. Its purpose is to improve controller
effectiveness and relieve frequency congestion by automating
repetitive transmission of essential but routine information.
Aviation medical examiner (AME). A physician with
training in aviation medicine designated by the Civil
Aerospace Medical Institute (CAMI).
AWOS. See automated weather observing system.
Azimuth card. A card that may be set, gyroscopically
controlled, or driven by a remote compass.
Back course (BC). The reciprocal of the localizer course
for an ILS. When fl ying a back-course approach, an aircraft
approaches the instrument runway from the end at which the
localizer antennas are installed.
Baro-aiding. A method of augmenting the GPS integrity
solution by using a non-satellite input source. To ensure that
baro-aiding is available, the current altimeter setting must
be entered as described in the operating manual.
Barometric scale. A scale on the dial of an altimeter to which
the pilot sets the barometric pressure level from which the
altitude shown by the pointers is measured.
BC. See back course.
Block altitude. A block of altitudes assigned by ATC to
allow altitude deviations; for example, “Maintain block
altitude 9 to 11 thousand.”
Cage. The black markings on the ball instrument indicating
its neutral position.
Calibrated. The instrument indication compared with a
standard value to determine the accuracy of the instrument.
Calibrated orifi ce. A hole of specifi c diameter used to delay
the pressure change in the case of a vertical speed indicator.
G-4
Calibrated airspeed. The speed at which the aircraft
is moving through the air, found by correcting IAS for
instrument and position errors.
CAS. Calibrated airspeed.
CDI. Course deviation indicator.
Changeover point (COP). A point along the route or
airway segment between two adjacent navigation facilities
or waypoints where changeover in navigation guidance
should occur.
Circling approach. A maneuver initiated by the pilot to
align the aircraft with a runway for landing when a straightin
landing from an instrument approach is not possible or is
not desirable.
Class A airspace. Airspace from 18,000 feet MSL up to and
including FL 600, including the airspace overlying the waters
within 12 NM of the coast of the 48 contiguous states and
Alaska; and designated international airspace beyond 12 NM
of the coast of the 48 contiguous states and Alaska within areas
of domestic radio navigational signal or ATC radar coverage,
and within which domestic procedures are applied.
Class B airspace. Airspace from the surface to 10,000 feet
MSL surrounding the nation’s busiest airports in terms of
IFR operations or passenger numbers. The confi guration of
each Class B airspace is individually tailored and consists
of a surface area and two or more layers, and is designed to
contain all published instrument procedures once an aircraft
enters the airspace. For all aircraft, an ATC clearance is
required to operate in the area, and aircraft so cleared receive
separation services within the airspace.
Class C airspace. Airspace from the surface to 4,000 feet
above the airport elevation (charted in MSL) surrounding
those airports having an operational control tower, serviced
by radar approach control, and having a certain number of IFR
operations or passenger numbers. Although the confi guration
of each Class C airspace area is individually tailored, the
airspace usually consists of a 5 NM radius core surface area
that extends from the surface up to 4,000 feet above the airport
elevation, and a 10 NM radius shelf area that extends from
1,200 feet to 4,000 feet above the airport elevation.
Class D airspace. Airspace from the surface to 2,500 feet
above the airport elevation (charted in MSL) surrounding
those airports that have an operational control tower. The
confi guration of each Class D airspace area is individually
tailored, and when instrument procedures are published, the
airspace is normally designed to contain the procedures.
Class E airspace. Airspace that is not Class A, Class B, Class
C, or Class D, and is controlled airspace.
Class G airspace. Airspace that is uncontrolled, except
when associated with a temporary control tower, and has
not been designated as Class A, Class B, Class C, Class D,
or Class E airspace.
Clean configuration. A confi guration in which all fl ight
control surfaces have been placed to create minimum drag.
In most aircraft this means fl aps and gear retracted.
Clearance. ATC permission for an aircraft to proceed under
specifi ed traffi c conditions within controlled airspace, for the
purpose of providing separation between known aircraft.
Clearance delivery. Control tower position responsible for
transmitting departure clearances to IFR fl ights.
Clearance limit. The fi x, point, or location to which an
aircraft is cleared when issued an air traffi c clearance.
Clearance on request. An IFR clearance not yet received
after fi ling a fl ight plan.
Clearance void time. Used by ATC, the time at which the
departure clearance is automatically canceled if takeoff has
not been made. The pilot must obtain a new clearance or
cancel the IFR fl ight plan if not off by the specifi ed time.
Clear ice. Glossy, clear, or translucent ice formed by the
relatively slow freezing of large, supercooled water droplets.
Compass course. A true course corrected for variation and
deviation errors.
Compass locator. A low-power, low- or medium-frequency
(L/MF) radio beacon installed at the site of the outer or middle
marker of an ILS.
Compass rose. A small circle graduated in 360° increments,
printed on navigational charts to show the amount of
compass variation at different locations, or on instruments
to indicate direction.
Computer navigation fix. A point used to define a
navigation track for an airborne computer system such as
GPS or FMS.
Concentric rings. Dashed-line circles depicted in the plan
view of IAP charts, outside of the reference circle, that show
en route and feeder facilities.
G-5
Cone of confusion. A cone-shaped volume of airspace
directly above a VOR station where no signal is received,
causing the CDI to fl uctuate.
Control and performance. A method of attitude instrument
fl ying in which one instrument is used for making attitude
changes, and the other instruments are used to monitor the
progress of the change.
Control display unit. A display interfaced with the master
computer, providing the pilot with a single control point
for all navigations systems, thereby reducing the number of
required flight deck panels.
Controlled airspace. An airspace of defi ned dimensions
within which ATC service is provided to IFR and VFR fl ights
in accordance with the airspace classifi cation. It includes
Class A, Class B, Class C, Class D, and Class E airspace.
Control pressures. The amount of physical exertion on the
control column necessary to achieve the desired attitude.
Convective weather. Unstable, rising air found in
cumiliform clouds.
Convective SIGMET. Weather advisory concerning
convective weather signifi cant to the safety of all aircraft,
including thunderstorms, hail, and tornadoes.
Coordinated flight. Flight with a minimum disturbance of
the forces maintaining equilibrium, established via effective
control use.
COP. See changeover point.
Coriolis illusion. The illusion of rotation or movement in an
entirely different axis, caused by an abrupt head movement,
while in a prolonged constant rate turn that has ceased
stimulating the brain’s motion sensing system.
Crew resource management (CRM). The effective
use of all available resources—human, hardware, and
information.
Critical areas. Areas where disturbances to the ILS localizer
and glide slope courses may occur when surface vehicles or
aircraft operate near the localizer or glide slope antennas.
CRM. See crew resource management.
Cross-check. The fi rst fundamental skill of instrument fl ight,
also known as “scan,” the continuous and logical observation
of instruments for attitude and performance information.
Cruise clearance. An ATC clearance issued to allow a
pilot to conduct fl ight at any altitude from the minimum
IFR altitude up to and including the altitude specifi ed in the
clearance. Also authorizes a pilot to proceed to and make an
approach at the destination airport.
Current induction. An electrical current being induced into,
or generated in, any conductor that is crossed by lines of fl ux
from any magnet.
DA. See decision altitude.
D.C. Direct current.
Dark adaptation. Physical and chemical adjustments of the
eye that make vision possible in relative darkness.
Deceleration error. A magnetic compass error that occurs
when the aircraft decelerates while fl ying on an easterly
or westerly heading, causing the compass card to rotate
toward South.
Decision altitude (DA). A specifi ed altitude in the precision
approach, charted in feet MSL, at which a missed approach
must be initiated if the required visual reference to continue
the approach has not been established.
Decision height (DH). A specifi ed altitude in the precision
approach, charted in height above threshold elevation,
at which a decision must be made either to continue the
approach or to execute a missed approach.
Deice. The act of removing ice accumulation from an
aircraft structure.
Density altitude. Pressure altitude corrected for nonstandard
temperature. Density altitude is used in computing the
performance of an aircraft and its engines.
Departure procedure (DP). Preplanned IFR ATC departure,
published for pilot use, in textual and graphic format.
Deviation. A magnetic compass error caused by local
magnetic fi elds within the aircraft. Deviation error is different
on each heading.
DGPS. Differential global positioning system.
DH. See decision height.
G-6
Differential Global Positioning System (DGPS). A system
that improves the accuracy of Global Navigation Satellite
Systems (GNSS) by measuring changes in variables to
provide satellite positioning corrections.
Direct indication. The true and instantaneous refl ection of
aircraft pitch-and-bank attitude by the miniature aircraft,
relative to the horizon bar of the attitude indicator.
Direct User Access Terminal System (DUATS). A system
that provides current FAA weather and fl ight plan fi ling
services to certifi ed civil pilots, via personal computer,
modem, or telephone access to the system. Pilots can request
specifi c types of weather briefi ngs and other pertinent data
for planned fl ights.
Distance circle. See reference circle.
Distance measuring equipment (DME). A pulse-type
electronic navigation system that shows the pilot, by an
instrument-panel indication, the number of nautical miles
between the aircraft and a ground station or waypoint.
DME. See distance measuring equipment.
DME arc. A fl ight track that is a constant distance from the
station or waypoint.
DOD. Department of Defense.
Doghouse. A turn-and-slip indicator dial mark in the shape
of a doghouse.
Domestic Reduced Vertical Separation Minimum
(DRVSM). Additional fl ight levels between FL 290 and FL
410 to provide operational, traffi c, and airspace effi ciency.
Double gimbal. A type of mount used for the gyro in an
attitude instrument. The axes of the two gimbals are at right
angles to the spin axis of the gyro, allowing free motion in
two planes around the gyro.
DP. See departure procedure.
Drag. The net aerodynamic force parallel to the relative
wind, usually the sum of two components: induced drag
and parasite drag.
Drag curve. The curve created when plotting induced drag
and parasite drag.
DUATS. See direct user access terminal system.
Duplex. Transmitting on one frequency and receiving on a
separate frequency.
Eddy currents. Current induced in a metal cup or disc when
it is crossed by lines of fl ux from a moving magnet.
EFAS. See En Route Flight Advisory Service.
EFC. See expect-further-clearance.
Electronic flight display (EFD). For the purpose of
standardization, any flight instrument display that uses
LCD or other image-producing system (Cathode Ray Tube
, etc.)
Elevator illusion. The sensation of being in a climb or
descent, caused by the kind of abrupt vertical accelerations
that result from up- or downdrafts.
Emergency. A distress or urgent condition.
Emphasis error. The result of giving too much attention
to a particular instrument during the cross-check, instead of
relying on a combination of instruments necessary for attitude
and performance information.
EM wave. Electromagnetic wave.
Encoding altimeter. A special type of pressure altimeter
used to send a signal to the air traffi c controller on the ground,
showing the pressure altitude the aircraft is fl ying.
En route facilities ring. Depicted in the plan view of IAP
charts, a circle which designates NAVAIDs, fi xes, and
intersections that are part of the en route low altitude airway
structure.
En Route Flight Advisory Service (EFAS). An en route
weather-only AFSS service.
En route high-altitude charts. Aeronautical charts for en
route instrument navigation at or above 18,000 feet MSL.
En route low-altitude charts. Aeronautical charts for en
route IFR navigation below 18,000 feet MSL.
Equivalent airspeed. Airspeed equivalent to CAS in
standard atmosphere at sea level. As the airspeed and pressure
altitude increase, the CAS becomes higher than it should be,
and a correction for compression must be subtracted from
the CAS.
G-7
Expect-further-clearance (EFC). The time a pilot can
expect to receive clearance beyond a clearance limit.
FAA. Federal Aviation Administration.
FAF. See fi nal approach fi x.
False horizon. Inaccurate visual information for aligning the
aircraft, caused by various natural and geometric formations
that disorient the pilot from the actual horizon.
Federal airways. Class E airspace areas that extend upward
from 1,200 feet to, but not including, 18,000 feet MSL, unless
otherwise specifi ed.
Feeder facilities. Used by ATC to direct aircraft to
intervening fi xes between the en route structure and the
initial approach fi x.
Final approach. Part of an instrument approach
procedure in which alignment and descent for landing are
accomplished.
Final approach fix (FAF). The fi x from which the IFR
fi nal approach to an airport is executed, and which identifi es
the beginning of the fi nal approach segment. An FAF is
designated on government charts by a Maltese cross symbol
for nonprecision approaches, and a lightning bolt symbol for
precision approaches.
Fixating. Staring at a single instrument, thereby interrupting
the cross-check process.
FL. See fl ight level.
Flight configurations. Adjusting the aircraft control surfaces
(including fl aps and landing gear) in a manner that will
achieve a specifi ed attitude.
Flight director indicator (FDI). One of the major components
of a flight director system, it provides steering commands that
the pilot (or the autopilot, if coupled) follows.
Flight level (FL). A measure of altitude (in hundreds of feet)
used by aircraft fl ying above 18,000 feet with the altimeter
set at 29.92" Hg.
Flight management system (FMS). Provides pilot and crew
with highly accurate and automatic long-range navigation
capability, blending available inputs from long- and shortrange
sensors.
Flight path. The line, course, or track along which an aircraft
is fl ying or is intended to be fl own.
Flight patterns. Basic maneuvers, fl own by reference to the
instruments rather than outside visual cues, for the purpose
of practicing basic attitude fl ying. The patterns simulate
maneuvers encountered on instrument fl ights such as holding
patterns, procedure turns, and approaches.
Flight strips. Paper strips containing instrument flight
information, used by ATC when processing fl ight plans.
FMS. See fl ight management system.
Form drag. The drag created because of the shape of a
component or the aircraft.
Fundamental skills. Pilot skills of instrument cross-check,
instrument interpretation, and aircraft control.
Glide slope (GS). Part of the ILS that projects a radio beam
upward at an angle of approximately 3° from the approach
end of an instrument runway. The glide slope provides
vertical guidance to aircraft on the fi nal approach course for
the aircraft to follow when making an ILS approach along
the localizer path.
Glide slope intercept altitude. The minimum altitude of an
intermediate approach segment prescribed for a precision
approach that ensures obstacle clearance.
Global landing system (GLS). An instrument approach with
lateral and vertical guidance with integrity limits (similar to
barometric vertical navigation (BRO VNAV).
Global navigation satellite systems (GNSS). Satellite
navigation systems that provide autonomous geo-spatial
positioning with global coverage. It allows small electronic
receivers to determine their location (longitude, latitude, and
altitude) to within a few meters using time signals transmitted
along a line of sight by radio from satellites.
GNSS. See global navigation satellite systems.
Global positioning system (GPS). Navigation system
that uses satellite rather than ground-based transmitters for
location information.
G-8
Goniometer. As used in radio frequency (RF) antenna
systems, a direction-sensing device consisting of two fi xed
loops of wire oriented 90° from each other, which separately
sense received signal strength and send those signals to two
rotors (also oriented 90°) in the sealed direction-indicating
instrument. The rotors are attached to the direction-indicating
needle of the instrument and rotated by a small motor until
minimum magnetic fi eld is sensed near the rotors.
GPS. See global positioning system.
GPS Approach Overlay Program. An authorization for
pilots to use GPS avionics under IFR for fl ying designated
existing nonprecision instrument approach procedures, with
the exception of LOC, LDA, and SDF procedures.
Graveyard spiral. The illusion of the cessation of a turn
while still in a prolonged, coordinated, constant rate turn,
which can lead a disoriented pilot to a loss of control of the
aircraft.
Great circle route. The shortest distance across the surface
of a sphere (the Earth) between two points on the surface.
Ground proximity warning system (GPWS). A system
designed to determine an aircraft’s clearance above the Earth
and provides limited predictability about aircraft position
relative to rising terrain.
Groundspeed. Speed over the ground, either closing speed to
the station or waypoint, or speed over the ground in whatever
direction the aircraft is going at the moment, depending upon
the navigation system used.
GS. See glide slope.
GWPS. See ground proximity warning system.
HAA. See height above airport.
HAL. See height above landing.
HAT. See height above touchdown elevation.
Hazardous attitudes. Five aeronautical decision-making
attitudes that may contribute to poor pilot judgment:
antiauthority, impulsivity, invulnerability, machismo, and
resignation.
Hazardous Inflight Weather Advisory Service (HIWAS).
Service providing recorded weather forecasts broadcast to
airborne pilots over selected VORs.
Head-up display (HUD). A special type of fl ight viewing
screen that allows the pilot to watch the fl ight instruments
and other data while looking through the windshield of the
aircraft for other traffi c, the approach lights, or the runway.
Height above airport (HAA). The height of the MDA above
the published airport elevation.
Height above landing (HAL). The height above a designated
helicopter landing area used for helicopter instrument
approach procedures.
Height above touchdown elevation (HAT). The DA/DH or
MDA above the highest runway elevation in the touchdown
zone (fi rst 3,000 feet of the runway).
HF. High frequency.
Hg. Abbreviation for mercury, from the Latin
hydrargyrum.
HIWAS. See Hazardous Inflight Weather Advisory
Service.
Holding. A predetermined maneuver that keeps aircraft
within a specifi ed airspace while awaiting further clearance
from ATC.
Holding pattern. A racetrack pattern, involving two turns
and two legs, used to keep an aircraft within a prescribed
airspace with respect to a geographic fi x. A standard pattern
uses right turns; nonstandard patterns use left turns.
Homing. Flying the aircraft on any heading required to keep
the needle pointing to the 0° relative bearing position.
Horizontal situation indicator (HSI). A fl ight navigation
instrument that combines the heading indicator with a CDI,
in order to provide the pilot with better situational awareness
of location with respect to the courseline.
HSI. See horizontal situation indicator.
HUD. See head-up display.
Human factors. A multidisciplinary fi eld encompassing the
behavioral and social sciences, engineering, and physiology,
to consider the variables that influence individual and
crew performance for the purpose of optimizing human
performance and reducing errors.
G-9
Hypoxia. A state of oxygen defi ciency in the body suffi cient
to impair functions of the brain and other organs.
IAF. See initial approach fi x.
IAP. See instrument approach procedures.
IAS. See indicated airspeed.
ICAO. See International Civil Aviation Organization.
Ident. Air Traffic Control request for a pilot to push
the button on the transponder to identify return on the
controller’s scope.
IFR. See instrument fl ight rules.
ILS. See instrument landing system.
ILS categories. Categories of instrument approach
procedures allowed at airports equipped with the following
types of instrument landing systems:
ILS Category I: Provides for approach to a height
above touchdown of not less than 200 feet, and with
runway visual range of not less than 1,800 feet.
ILS Category II: Provides for approach to a height
above touchdown of not less than 100 feet and with
runway visual range of not less than 1,200 feet.
ILS Category IIIA: Provides for approach without
a decision height minimum and with runway visual
range of not less than 700 feet.
ILS Category IIIB: Provides for approach without
a decision height minimum and with runway visual
range of not less than 150 feet.
ILS Category IIIC: Provides for approach without a
decision height minimum and without runway visual
range minimum.
IMC. See instrument meteorological conditions.
Indicated airspeed (IAS). Shown on the dial of the
instrument airspeed indicator on an aircraft. Directly related
to calibrated airspeed (CAS), IAS includes instrument errors
and position error.
Indirect indication. A refl ection of aircraft pitch-and-bank
attitude by the instruments other than the attitude indicator.
Induced drag. Drag caused by the same factors that produce
lift; its amount varies inversely with airspeed. As airspeed
decreases, the angle of attack must increase, in turn increasing
induced drag.
Induction icing. A type of ice in the induction system that
reduces the amount of air available for combustion. The most
commonly found induction icing is carburetor icing.
Inertial navigation system (INS). A computer-based
navigation system that tracks the movement of an aircraft
via signals produced by onboard accelerometers. The initial
location of the aircraft is entered into the computer, and all
subsequent movement of the aircraft is sensed and used to
keep the position updated. An INS does not require any inputs
from outside signals.
Initial approach fix (IAF). The fi x depicted on IAP charts
where the instrument approach procedure (IAP) begins unless
otherwise authorized by ATC.
Inoperative components. Higher minimums are prescribed
when the specified visual aids are not functioning; this
information is listed in the Inoperative Components Table found
in the United States Terminal Procedures Publications.
INS. See inertial navigation system.
Instantaneous vertical speed indicator (IVSI). Assists in
interpretation by instantaneously indicating the rate of climb
or descent at a given moment with little or no lag as displayed
in a vertical speed indicator (VSI).
Instrument approach procedures (IAP). A series of
predetermined maneuvers for the orderly transfer of an
aircraft under IFR from the beginning of the initial approach
to a landing or to a point from which a landing may be
made visually.
Instrument flight rules (IFR). Rules and regulations
established by the Federal Aviation Administration to govern
fl ight under conditions in which fl ight by outside visual
reference is not safe. IFR fl ight depends upon fl ying by
reference to instruments in the fl ight deck, and navigation is
accomplished by reference to electronic signals.
Instrument landing system (ILS). An electronic system
that provides both horizontal and vertical guidance to a
specifi c runway, used to execute a precision instrument
approach procedure.
Instrument meteorological conditions (IMC).
Meteorological conditions expressed in terms of visibility,
distance from clouds, and ceiling less than the minimums
specifi ed for visual meteorological conditions, requiring
operations to be conducted under IFR.
G-10
Instrument takeoff. Using the instruments rather than
outside visual cues to maintain runway heading and execute
a safe takeoff.
Interference drag. Drag generated by the collision of
airstreams creating eddy currents, turbulence, or restrictions
to smooth flow.
International Civil Aviation Organization (ICAO). The
United Nations agency for developing the principles and
techniques of international air navigation, and fostering planning
and development of international civil air transport.
International standard atmosphere (IAS). A model of
standard variation of pressure and temperature.
Inversion illusion. The feeling that the aircraft is tumbling
backwards, caused by an abrupt change from climb to straightand-
level fl ight while in situations lacking visual reference.
Inverter. A solid-state electronic device that converts D.C.
into A.C. current of the proper voltage and frequency to
operate A.C. gyro instruments.
Isogonic lines. Lines drawn across aeronautical charts to
connect points having the same magnetic variation.
IVSI. See instantaneous vertical speed indicator.
Jet route. A route designated to serve fl ight operations from
18,000 feet MSL up to and including FL 450.
Jet stream. A high-velocity narrow stream of winds, usually
found near the upper limit of the troposphere, which fl ows
generally from west to east.
KIAS. Knots indicated airspeed.
Kollsman window. A barometric scale window of a
sensitive altimeter used to adjust the altitude for the
altimeter setting.
LAAS. See local area augmentation system.
Lag. The delay that occurs before an instrument needle attains
a stable indication.
Land as soon as possible. ATC instruction to pilot. Land
without delay at the nearest suitable area, such as an open
fi eld, at which a safe approach and landing is assured.
Land as soon as practical. ATC instruction to pilot. The
landing site and duration of fl ight are at the discretion of the
pilot. Extended fl ight beyond the nearest approved landing
area is not recommended.
Land immediately. ATC instruction to pilot. The urgency
of the landing is paramount. The primary consideration is
to ensure the survival of the occupants. Landing in trees,
water, or other unsafe areas should be considered only as
a last resort.
LDA. See localizer-type directional aid.
Lead radial. The radial at which the turn from the DME arc
to the inbound course is started.
Leans, the. A physical sensation caused by an abrupt
correction of a banked attitude entered too slowly to
stimulate the motion sensing system in the inner ear. The
abrupt correction can create the illusion of banking in the
opposite direction.
Lift. A component of the total aerodynamic force on an airfoil
and acts perpendicular to the relative wind.
Lines of flux. Invisible lines of magnetic force passing
between the poles of a magnet.
L/MF. See low or medium frequency.
LMM. See locator middle marker.
Load factor. The ratio of a specifi ed load to the total weight
of the aircraft. The specifi ed load is expressed in terms of
any of the following: aerodynamic forces, inertial forces, or
ground or water reactions.
Loadmeter. A type of ammeter installed between the generator
output and the main bus in an aircraft electrical system.
LOC. See localizer.
Local area augmentation system (LAAS). A differential
global positioning system (DGPS) that improves the accuracy
of the system by determining position error from the GPS
satellites, then transmitting the error, or corrective factors,
to the airborne GPS receiver.
G-11
Localizer (LOC). The portion of an ILS that gives left/right
guidance information down the centerline of the instrument
runway for fi nal approach.
Localizer-type directional aid (LDA). A NAVAID used
for nonprecision instrument approaches with utility and
accuracy comparable to a localizer but which is not a part
of a complete ILS and is not aligned with the runway. Some
LDAs are equipped with a glide slope.
Locator middle marker (LMM). Nondirectional radio
beacon (NDB) compass locator, collocated with a middle
marker (MM).
Locator outer marker (LOM). NDB compass locator,
collocated with an outer marker (OM).
LOM. See locator outer marker.
Long range navigation (LORAN). An electronic
navigational system by which hyperbolic lines of position
are determined by measuring the difference in the time of
reception of synchronized pulse signals from two fi xed
transmitters. LORAN A operates in the 1750 to 1950 kHz
frequency band. LORAN C and D operate in the 100 to 110
kHz frequency band.
LORAN. See long range navigation.
Low or medium frequency. A frequency range between
190–535 kHz with the medium frequency above 300
kHz. Generally associated with nondirectional beacons
transmitting a continuous carrier with either a 400 or 1,020
Hz modulation.
Lubber line. The reference line used in a magnetic compass
or heading indicator.
MAA. See maximum authorized altitude.
Mach number. The ratio of the true airspeed of the aircraft
to the speed of sound in the same atmospheric conditions,
named in honor of Ernst Mach, late 19th century physicist.
Mach meter. The instrument that displays the ratio of the
speed of sound to the true airspeed an aircraft is flying.
Magnetic bearing (MB). The direction to or from a radio
transmitting station measured relative to magnetic north.
Magnetic heading (MH). The direction an aircraft is pointed
with respect to magnetic north.
Mandatory altitude. An altitude depicted on an instrument
approach chart with the altitude value both underscored and
overscored. Aircraft are required to maintain altitude at the
depicted value.
Mandatory block altitude. An altitude depicted on an
instrument approach chart with two underscored and
overscored altitude values between which aircraft are
required to maintain altitude.
MAP. See missed approach point.
Margin identification. The top and bottom areas on an
instrument approach chart that depict information about
the procedure, including airport location and procedure
identifi cation.
Marker beacon. A low-powered transmitter that directs its
signal upward in a small, fan-shaped pattern. Used along the
fl ight path when approaching an airport for landing, marker
beacons indicate both aurally and visually when the aircraft
is directly over the facility.
Maximum altitude. An altitude depicted on an instrument
approach chart with overscored altitude value at which or
below aircraft are required to maintain altitude.
Maximum authorized altitude (MAA). A published altitude
representing the maximum usable altitude or fl ight level for
an airspace structure or route segment.
MB. See magnetic bearing.
MCA. See minimum crossing altitude.
MDA. See minimum descent altitude.
MEA. See minimum en route altitude.
Mean sea level. The average height of the surface of the
sea at a particular location for all stages of the tide over a
19-year period.
MFD. See multi-function display.
MH. See magnetic heading.
MHz. Megahertz.
G-12
Microwave landing system (MLS). A precision instrument
approach system operating in the microwave spectrum which
normally consists of an azimuth station, elevation station,
and precision distance measuring equipment.
Mileage breakdown. A fi x indicating a course change
that appears on the chart as an “x” at a break between two
segments of a federal airway.
Military operations area (MOA). Airspace established for
the purpose of separating certain military training activities
from IFR traffi c.
Military training route (MTR). Airspace of defi ned vertical
and lateral dimensions established for the conduct of military
training at airspeeds in excess of 250 knots indicated airspeed
(KIAS).
Minimum altitude. An altitude depicted on an instrument
approach chart with the altitude value underscored. Aircraft are
required to maintain altitude at or above the depicted value.
Minimum crossing altitude (MCA). The lowest allowed
altitude at certain fi xes an aircraft must cross when proceeding
in the direction of a higher minimum en route altitude
(MEA).
Minimum descent altitude (MDA). The lowest altitude (in
feet MSL) to which descent is authorized on fi nal approach,
or during circle-to-land maneuvering in execution of a
nonprecision approach.
Minimum en route altitude (MEA). The lowest published
altitude between radio fixes that ensures acceptable
navigational signal coverage and meets obstacle clearance
requirements between those fi xes.
Minimum obstruction clearance altitude (MOCA). The
lowest published altitude in effect between radio fi xes on VOR
airways, off-airway routes, or route segments, which meets
obstacle clearance requirements for the entire route segment
and which ensures acceptable navigational signal coverage
only within 25 statute (22 nautical) miles of a VOR.
Minimum reception altitude (MRA). The lowest altitude
at which an airway intersection can be determined.
Minimum safe altitude (MSA). The minimum altitude
depicted on approach charts which provides at least 1,000 feet
of obstacle clearance for emergency use within a specifi ed
distance from the listed navigation facility.
Minimum vectoring altitude (MVA). An IFR altitude lower
than the minimum en route altitude (MEA) that provides
terrain and obstacle clearance.
Minimums section. The area on an IAP chart that displays the
lowest altitude and visibility requirements for the approach.
Missed approach. A maneuver conducted by a pilot when an
instrument approach cannot be completed to a landing.
Missed approach point (MAP). A point prescribed in each
instrument approach at which a missed approach procedure
shall be executed if the required visual reference has not
been established.
Mixed ice. A mixture of clear ice and rime ice.
MLS. See microwave landing system.
MM. Middle marker.
MOA. See military operations area.
MOCA. See minimum obstruction clearance altitude.
Mode C. Altitude reporting transponder mode.
MRA. See minimum reception altitude.
MSA. See minimum safe altitude.
MSL. See mean sea level.
MTR. See military training route.
Multi-function display (MFD). Small screen (CRT or LCD)
in an aircraft that can be used to display information to the
pilot in numerous configurable ways. Often an MFD will be
used in concert with a Primary Flight Display.
MVA. See minimum vectoring altitude.
NACG. See National Aeronautical Charting Group.
NAS. See National Airspace System.
National Airspace System (NAS). The common network of
United States airspace—air navigation facilities, equipment
and services, airports or landing areas; aeronautical charts,
information and services; rules, regulations and procedures,
technical information; and manpower and material.
G-13
National Aeronautical Charting Group (NACG). A
Federal agency operating under the FAA, responsible for
publishing charts such as the terminal procedures and en
route charts.
National Route Program (NRP). A set of rules and
procedures designed to increase the fl exibility of user fl ight
planning within published guidelines.
National Security Area (NSA). Areas consisting of airspace of
defi ned vertical and lateral dimensions established at locations
where there is a requirement for increased security and safety
of ground facilities. Pilots are requested to voluntarily avoid
fl ying through the depicted NSA. When it is necessary to
provide a greater level of security and safety, fl ight in NSAs
may be temporarily prohibited. Regulatory prohibitions are
disseminated via NOTAMs.
National Transportation Safety Board (NTSB). A United
States Government independent organization responsible for
investigations of accidents involving aviation, highways,
waterways, pipelines, and railroads in the United States.
NTSB is charged by congress to investigate every civil
aviation accident in the United States.
NAVAID. Naviagtional aid.
NAV/COM. Navigation and communication radio.
NDB. See nondirectional radio beacon.
NM. Nautical mile.
NOAA. National Oceanic and Atmospheric Administration.
No-gyro approach. A radar approach that may be used in
case of a malfunctioning gyro-compass or directional gyro.
Instead of providing the pilot with headings to be fl own,
the controller observes the radar track and issues control
instructions “turn right/left” or “stop turn,” as appropriate.
Nondirectional radio beacon (NDB). A ground-based radio
transmitter that transmits radio energy in all directions.
Nonprecision approach. A standard instrument approach
procedure in which only horizontal guidance is provided.
No procedure turn (NoPT). Term used with the appropriate
course and altitude to denote that the procedure turn is not
required.
NoPT. See no procedure turn.
Notice to Airmen (NOTAM). A notice filed with an aviation
authority to alert aircraft pilots of any hazards en route or at
a specific location. The authority in turn provides means of
disseminating relevant NOTAMs to pilots.
NRP. See National Route Program.
NSA. See National Security Area.
NTSB. See National Transportation Safety Board.
NWS. National Weather Service.
Obstacle departure procedures (ODP). Obstacle clearance
protection provided to aircraft in instrument meteorological
conditions (IMC).
ODP. See obstacle departure procedures.
OM. Outer marker.
Omission error. The failure to anticipate significant
instrument indications following attitude changes; for
example, concentrating on pitch control while forgetting
about heading or roll information, resulting in erratic control
of heading and bank.
Optical illusion. A misleading visual image. For the
purpose of this handbook, the term refers to the brain’s
misinterpretation of features on the ground associated
with landing, which causes a pilot to misread the spatial
relationships between the aircraft and the runway.
Orientation. Awareness of the position of the aircraft and
of oneself in relation to a specifi c reference point.
Otolith organ. An inner ear organ that detects linear
acceleration and gravity orientation.
Outer marker. A marker beacon at or near the glide slope
intercept altitude of an ILS approach. It is normally located
four to seven miles from the runway threshold on the
extended centerline of the runway.
Overcontrolling. Using more movement in the control
column than is necessary to achieve the desired pitch-and
bank condition.
Overpower. To use more power than required for the purpose
of achieving a faster rate of airspeed change.
G-14
P-static. See precipitation static.
PAPI. See precision approach path indicator.
PAR. See precision approach radar.
Parasite drag. Drag caused by the friction of air moving
over the aircraft structure; its amount varies directly with
the airspeed.
PFD. See primary flight display.
PIC. See pilot-in-command.
Pilot-in-command (PIC). The pilot responsible for the
operation and safety of an aircraft.
Pilot report (PIREP). Report of meteorological phenomena
encountered by aircraft.
Pilot’s Operating Handbook/Airplane Flight Manual
(POH/AFM). FAA-approved documents published by the
airframe manufacturer that list the operating conditions for
a particular model of aircraft.
PIREP. See pilot report.
Pitot pressure. Ram air pressure used to measure airspeed.
Pitot-static head. A combination pickup used to sample pitot
pressure and static air pressure.
Plan view. The overhead view of an approach procedure on
an instrument approach chart. The plan view depicts the routes
that guide the pilot from the en route segments to the IAF.
POH/AFM. See Pilot’s Operating Handbook/Airplane
Flight Manual.
Point-in-space approach. A type of helicopter instrument
approach procedure to a missed approach point more than
2,600 feet from an associated helicopter landing area.
Position error. Error in the indication of the altimeter, ASI,
and VSI caused by the air at the static system entrance not
being absolutely still.
Position report. A report over a known location as
transmitted by an aircraft to ATC.
Precession. The characteristic of a gyroscope that causes an
applied force to be felt, not at the point of application, but
90° from that point in the direction of rotation.
Precipitation static (P-static). A form of radio interference
caused by rain, snow, or dust particles hitting the antenna and
inducing a small radio-frequency voltage into it.
Precision approach. A standard instrument approach
procedure in which both vertical and horizontal guidance
is provided.
Precision approach path indicator (PAPI). A system of
lights similar to the VASI, but consisting of one row of lights
in two- or four-light systems. A pilot on the correct glide slope
will see two white lights and two red lights. See VASI.
Precision approach radar (PAR). A type of radar used
at an airport to guide an aircraft through the fi nal stages of
landing, providing horizontal and vertical guidance. The
radar operator directs the pilot to change heading or adjust
the descent rate to keep the aircraft on a path that allows it
to touch down at the correct spot on the runway.
Precision runway monitor (PRM). System allows
simultaneous, independent Instrument Flight Rules (IFR)
approaches at airports with closely spaced parallel runways.
Preferred IFR routes. Routes established in the major
terminal and en route environments to increase system
effi ciency and capacity. IFR clearances are issued based on
these routes, listed in the A/FD except when severe weather
avoidance procedures or other factors dictate otherwise.
Pressure altitude. Altitude above the standard 29.92" Hg
plane.
Prevailing visibility. The greatest horizontal visibility
equaled or exceeded throughout at least half the horizon
circle (which is not necessarily continuous).
Primary and supporting. A method of attitude instrument
fl ying using the instrument that provides the most direct
indication of attitude and performance.
Primary flight display (PFD). A display that provides
increased situational awareness to the pilot by replacing the
traditional six instruments used for instrument flight with
an easy-to-scan display that provides the horizon, airspeed,
altitude, vertical speed, trend, trim, rate of turn among other
key relevant indications.
PRM. See precision runway monitor.
Procedure turn. A maneuver prescribed when it is necessary
to reverse direction to establish an aircraft on the intermediate
approach segment or fi nal approach course.
G-15
Profile view. Side view of an IAP chart illustrating the vertical
approach path altitudes, headings, distances, and fi xes.
Prohibited area. Designated airspace within which fl ight of
aircraft is prohibited.
Propeller/rotor modulation error. Certain propeller RPM
settings or helicopter rotor speeds can cause the VOR course
deviation indicator (CDI) to fl uctuate as much as ±6°. Slight
changes to the RPM setting will normally smooth out this
roughness.
Rabbit, the. High-intensity fl asher system installed at many
large airports. The fl ashers consist of a series of brilliant
blue-white bursts of light fl ashing in sequence along the
approach lights, giving the effect of a ball of light traveling
towards the runway.
Radar. Radio Detection And Ranging.
Radar approach. The controller provides vectors while
monitoring the progress of the fl ight with radar, guiding
the pilot through the descent to the airport/heliport or to a
specifi c runway.
Radials. The courses oriented from a station.
Radio or radar altimeter. An electronic altimeter that
determines the height of an aircraft above the terrain by
measuring the time needed for a pulse of radio-frequency
energy to travel from the aircraft to the ground and return.
Radio frequency (RF). A term that refers to alternating
current (AC) having characteristics such that, if the current is
input to antenna, an electromagnetic (EM) field is generated
suitable for wireless broadcasting and/or communications.
Radio magnetic indicator (RMI). An electronic navigation
instrument that combines a magnetic compass with an ADF
or VOR. The card of the RMI acts as a gyro-stabilized
magnetic compass, and shows the magnetic heading the
aircraft is fl ying.
Radio wave. An electromagnetic wave (EM wave) with
frequency characteristics useful for radio transmission.
RAIM. See receiver autonomous integrity monitoring.
Random RNAV routes. Direct routes, based on area
navigation capability, between waypoints defi ned in terms
of latitude/longitude coordinates, degree-distance fi xes, or
offsets from established routes/airways at a specifi ed distance
and direction.
Ranging signals. Transmitted from the GPS satellite, these
allow the aircraft’s receiver to determine range (distance)
from each satellite.
RB. See relative bearing.
RBI. See relative bearing indicator.
RCO. See remote communications outlet.
Receiver autonomous integrity monitoring (RAIM).
A system used to verify the usability of the received GPS
signals and warns the pilot of any malfunction in the
navigation system. This system is required for IFR-certifi ed
GPS units.
Recommended altitude. An altitude depicted on an
instrument approach chart with the altitude value neither
underscored nor overscored. The depicted value is an
advisory value.
Receiver-transmitter (RT). A system that receives and
transmits a signal and an indicator.
Reduced vertical separation minimum (RVSM). Reduces
the vertical separation between flight level (FL) 290–410
from 2,000 feet to 1,000 feet and makes six additional FLs
available for operation. Also see DRVSM.
Reference circle (also, distance circle). The circle depicted
in the plan view of an IAP chart that typically has a 10 NM
radius, within which chart the elements are drawn to scale.
Regions of command. The “regions of normal and reversed
command” refers to the relationship between speed and the
power required to maintain or change that speed in fl ight.
REIL. See runway end identifi er lights.
Relative bearing (RB). The angular difference between the
aircraft heading and the direction to the station, measured
clockwise from the nose of the aircraft.
Relative bearing indicator (RBI). Also known as the fi xedcard
ADF, zero is always indicated at the top of the instrument
and the needle indicates the relative bearing to the station.
Relative wind. Direction of the airfl ow produced by an object
moving through the air. The relative wind for an airplane in
fl ight fl ows in a direction parallel with and opposite to the
direction of fl ight; therefore, the actual fl ight path of the
airplane determines the direction of the relative wind.
G-16
Remote communications outlet (RCO). An unmanned
communications facility that is remotely controlled by air
traffi c personnel.
Required navigation performance (RNP). A specified level
of accuracy defined by a lateral area of confined airspace in
which an RNP-certified aircraft operates.
Restricted area. Airspace designated under 14 CFR part
73 within which the fl ight of aircraft, while not wholly
prohibited, is subject to restriction.
Reverse sensing. The VOR needle appearing to indicate the
reverse of normal operation.
RF. Radio frequency.
Rhodopsin. The photosensitive pigments that initiate the
visual response in the rods of the eye.
Rigidity. The characteristic of a gyroscope that prevents its
axis of rotation tilting as the Earth rotates.
Rime ice. Rough, milky, opaque ice formed by the
instantaneous freezing of small supercooled water droplets.
Risk. The future impact of a hazard that is not eliminated
or controlled.
RMI. See radio magnetic indicator.
RNAV. See area navigation.
RNP. See required navigation performance.
Runway end identifier lights (REIL). A pair of synchronized
fl ashing lights, located laterally on each side of the runway
threshold, providing rapid and positive identifi cation of the
approach end of a runway.
Runway visibility value (RVV). The visibility determined
for a particular runway by a transmissometer.
Runway visual range (RVR). The instrumentally derived
horizontal distance a pilot should be able to see down the
runway from the approach end, based on either the sighting
of high-intensity runway lights, or the visual contrast of
other objects.
RVR. See runway visual range.
RVV. See runway visibility value.
SA. See selective availability.
St. Elmo’s Fire. A corona discharge which lights up the aircraft
surface areas where maximum static discharge occurs.
Satellite ephemeris data. Data broadcast by the GPS
satellite containing very accurate orbital data for that
satellite, atmospheric propagation data, and satellite clock
error data.
Scan. The fi rst fundamental skill of instrument fl ight, also
known as “cross-check;” the continuous and logical observation
of instruments for attitude and performance information.
SDF. See simplifi ed directional facility.
Selective availability (SA). A satellite technology permitting
the Department of Defense (DOD) to create, in the interest
of national security, a signifi cant clock and ephemeris error
in the satellites, resulting in a navigation error.
Semicircular canal. An inner ear organ that detects angular
acceleration of the body.
Sensitive altimeter. A form of multipointer pneumatic
altimeter with an adjustable barometric scale that allows the
reference pressure to be set to any desired level.
SIDS. See standard instrument departure procedures.
SIGMET. The acronym for Signifi cant Meteorological
information. A weather advisory issued concerning weather
signifi cant to the safety of all aircraft.
Signal-to-noise ratio. An indication of signal strength
received compared to background noise, which is a measure
of how adequate the received signal is.
Simplex. Transmission and reception on the same
frequency.
Simplified directional facility (SDF). A NAVAID used
for nonprecision instrument approaches. The fi nal approach
course is similar to that of an ILS localizer; however, the
SDF course may be offset from the runway, generally not
more than 3°, and the course may be wider than the localizer,
resulting in a lower degree of accuracy.
Single-pilot resource management (SRM). The ability for
crew or pilot to manage all resources effectively to ensure
the outcome of the flight is successful.
G-17
Situational awareness. Pilot knowledge of where the aircraft
is in regard to location, air traffi c control, weather, regulations,
aircraft status, and other factors that may affect fl ight.
Skidding turn. An uncoordinated turn in which the rate of
turn is too great for the angle of bank, pulling the aircraft to
the outside of the turn.
Skin friction drag. Drag generated between air molecules
and the solid surface of the aircraft.
Slant range. The horizontal distance from the aircraft antenna
to the ground station, due to line-of-sight transmission of the
DME signal.
Slaved compass. A system whereby the heading gyro is
“slaved to,” or continuously corrected to bring its direction
readings into agreement with a remotely located magnetic
direction sensing device (usually this is a fl ux valve or fl ux
gate compass).
Slipping turn. An uncoordinated turn in which the aircraft
is banked too much for the rate of turn, so the horizontal lift
component is greater than the centrifugal force, pulling the
aircraft toward the inside of the turn.
Small airplane. An airplane of 12,500 pounds or less
maximum certifi cated takeoff weight.
Somatogravic illusion. The misperception of being
in a nose-up or nose-down attitude, caused by a rapid
acceleration or deceleration while in fl ight situations that
lack visual reference.
Spatial disorientation. The state of confusion due to
misleading information being sent to the brain from various
sensory organs, resulting in a lack of awareness of the aircraft
position in relation to a specifi c reference point.
Special use airspace. Airspace in which fl ight activities are
subject to restrictions that can create limitations on the mixed
use of airspace. Consists of prohibited, restricted, warning,
military operations, and alert areas.
SRM. See single-pilot resource management.
SSR. See secondary surveillance radar.
SSV. See standard service volume.
Standard holding pattern. A holding pattern in which all
turns are made to the right.
Standard instrument departure procedures (SIDS).
Published procedures to expedite clearance delivery and to
facilitate transition between takeoff and en route operations.
Standard rate turn. A turn in which an aircraft changes its
direction at a rate of 3° per second (360° in 2 minutes) for
low- or medium-speed aircraft. For high-speed aircraft, the
standard rate turn is 1-1/2° per second (360° in 4 minutes).
Standard service volume (SSV). Defi nes the limits of the
volume of airspace which the VOR serves.
Standard terminal arrival route (STAR). A preplanned
IFR ATC arrival procedure published for pilot use in graphic
and/or textual form.
STAR. See standard terminal arrival route.
Static longitudinal stability. The aerodynamic pitching
moments required to return the aircraft to the equilibrium
angle of attack.
Static pressure. Pressure of air that is still, or not moving,
measured perpendicular to the surface of the aircraft.
Steep turns. In instrument fl ight, any turn greater than standard
rate; in visual fl ight, anything greater than a 45° bank.
Stepdown fix. The point after which additional descent is
permitted within a segment of an IAP.
Strapdown system. An INS in which the accelerometers
and gyros are permanently “strapped down” or aligned with
the three axes of the aircraft.
Stress. The body’s response to demands placed upon it.
Structural icing. The accumulation of ice on the exterior
of the aircraft.
Suction relief valve. A relief valve in an instrument vacuum
system required to maintain the correct low pressure inside
the instrument case for the proper operation of the gyros.
Synchro. A device used to transmit indications of angular
movement or position from one location to another.
Synthetic vision. A realistic display depiction of the aircraft
in relation to terrain and flight path.
G-18
TAA. See terminal arrival area.
TACAN. See tactical air navigation.
Tactical air navigation (TACAN). An electronic navigation
system used by military aircraft, providing both distance and
direction information.
TAWS. See terrain awareness and warning system.
TCAS. See traffic alert collision avoidance system.
TCH. See threshold crossing height.
TDZE. See touchdown zone elevation.
TEC. See Tower En Route Control.
Technique. The manner in which procedures are executed.
Temporary flight restriction (TFR). Restriction to fl ight
imposed in order to:
1. Protect persons and property in the air or on the
surface from an existing or imminent fl ight associated
hazard;
2. Provide a safe environment for the operation of
disaster relief aircraft;
3. Prevent an unsafe congestion of sightseeing aircraft
above an incident;
4. Protect the President, Vice President, or other public
fi gures; and,
5. Provide a safe environment for space agency
operations.
Pilots are expected to check appropriate NOTAMs during
fl ight planning when conducting fl ight in an area where a
temporary fl ight restriction is in effect.
Tension. Maintaining an excessively strong grip on the control
column, usually resulting in an overcontrolled situation.
Terminal Instrument Approach Procedure (TERP).
Prescribes standardized methods for use in designing
instrument flight procedures.
Terminal arrival area (TAA). A procedure to provide a
new transition method for arriving aircraft equipped with
FMS and/or GPS navigational equipment. The TAA contains
a “T” structure that normally provides a NoPT for aircraft
using the approach.
TERP. See terminal instrument approach procedure.
Terrain Awareness and Warning System (TAWS). A
timed-based system that provides information concerning
potential hazards with fixed objects by using GPS positioning
and a database of terrain and obstructions to provide true
predictability of the upcoming terrain and obstacles.
TFR. See temporary fl ight restriction.
Threshold crossing height (TCH). The theoretical height
above the runway threshold at which the aircraft’s glide
slope antenna would be if the aircraft maintains the trajectory
established by the mean ILS glide slope or MLS glide path.
Thrust (aerodynamic force). The forward aerodynamic
force produced by a propeller, fan, or turbojet engine as it
forces a mass of air to the rear, behind the aircraft.
Time and speed table. A table depicted on an instrument
approach procedure chart that identifi es the distance from the
FAF to the MAP, and provides the time required to transit
that distance based on various groundspeeds.
Timed turn. A turn in which the clock and the turn
coordinator are used to change heading a defi nite number of
degrees in a given time.
TIS. See traffic information service.
Title 14 of the Code of Federal Regulations (14 CFR).
The federal aviation regulations governing the operation of
aircraft, airways, and airmen.
Touchdown zone elevation (TDZE). The highest elevation
in the first 3,000 feet of the landing surface, TDZE is
indicated on the instrument approach procedure chart when
straight-in landing minimums are authorized.
Tower En Route Control (TEC). The control of IFR en route
traffi c within delegated airspace between two or more adjacent
approach control facilities, designed to expedite traffi c and
reduce control and pilot communication requirements.
TPP. See United States Terminal Procedures Publication.
Tracking. Flying a heading that will maintain the desired track
to or from the station regardless of crosswind conditions.
Traffic Alert Collision Avoidance System (TCAS).
An airborne system developed by the FAA that operates
independently from the ground-based Air Traffic Control
system. Designed to increase flight deck awareness of
proximate aircraft and to serve as a “last line of defense” for
the prevention of mid-air collisions.
G-19
Traffic information service (TIS). A ground-based service
providing information to the flight deck via data link using
the S-mode transponder and altitude encoder to improve the
safety and efficiency of “see and avoid” flight through an
automatic display that informs the pilot of nearby traffic.
Transcribed Weather Broadcast (TWEB). Meteorological
and aeronautical data recorded on tapes and broadcast over
selected NAVAIDs. Generally, the broadcast contains routeoriented
data with specially prepared NWS forecasts, infl ight
advisories, and winds aloft. It also includes selected current
information such as weather reports (METAR/SPECI),
NOTAMs, and special notices.
Transponder. The airborne portion of the ATC radar
beacon system.
Transponder code. One of 4,096 four-digit discrete codes
ATC assigns to distinguish between aircraft.
Trend. Immediate indication of the direction of aircraft
movement, as shown on instruments.
Trim. Adjusting the aerodynamic forces on the control
surfaces so that the aircraft maintains the set attitude without
any control input.
TWEB. See Transcribed Weather Broadcast.
True airspeed. Actual airspeed, determined by applying a
correction for pressure altitude and temperature to the CAS.
UHF. See ultra-high frequency.
Ultra-high frequency (UHF). The range of electromagnetic
frequencies between 962 MHz and 1213 MHz.
Uncaging. Unlocking the gimbals of a gyroscopic instrument,
making it susceptible to damage by abrupt fl ight maneuvers
or rough handling.
Underpower. Using less power than required for the purpose
of achieving a faster rate of airspeed change.
United States Terminal Procedures Publication (TPP).
Booklets published in regional format by the NACO that
include DPs, STARs, IAPs, and other information pertinent
to IFR fl ight.
Unusual attitude. An unintentional, unanticipated, or
extreme aircraft attitude.
User-defined waypoints. Waypoint location and other data
which may be input by the user, this is the only GPS database
information that may be altered (edited) by the user.
Variation. Compass error caused by the difference in
the physical locations of the magnetic north pole and the
geographic north pole.
VASI. See visual approach slope indicator.
VDP. See visual descent point.
Vectoring. Navigational guidance by assigning headings.
Venturi tube. A specially shaped tube attached to the outside
of an aircraft to produce suction to allow proper operation
of gyro instruments.
Vertical speed indicator (VSI). A rate-of-pressure change
instrument that gives an indication of any deviation from a
constant pressure level.
Very-high frequency (VHF). A band of radio frequencies
falling between 30 and 300 MHz.
Very-high frequency omnidirectional range (VOR).
Electronic navigation equipment in which the fl ight deck
instrument identifi es the radial or line from the VOR station,
measured in degrees clockwise from magnetic north, along
which the aircraft is located.
Vestibule. The central cavity of the bony labyrinth of the ear,
or the parts of the membranous labyrinth that it contains.
VFR. See visual fl ight rules.
VFR-on-top. ATC authorization for an IFR aircraft to operate
in VFR conditions at any appropriate VFR altitude.
VFR over-the-top. A VFR operation in which an aircraft
operates in VFR conditions on top of an undercast.
Victor airways. Airways based on a centerline that extends
from one VOR or VORTAC navigation aid or intersection,
to another navigation aid (or through several navigation aids
or intersections); used to establish a known route for en route
procedures between terminal areas.
G-20
Visual approach slope indicator (VASI). A visual aid of
lights arranged to provide descent guidance information
during the approach to the runway. A pilot on the correct
glide slope will see red lights over white lights.
Visual descent point (VDP). A defi ned point on the fi nal
approach course of a nonprecision straight-in approach
procedure from which normal descent from the MDA to the
runway touchdown point may be commenced, provided the
runway environment is clearly visible to the pilot.
Visual flight rules (VFR). Flight rules adopted by the
FAA governing aircraft fl ight using visual references. VFR
operations specify the amount of ceiling and the visibility the
pilot must have in order to operate according to these rules.
When the weather conditions are such that the pilot can not
operate according to VFR, he or she must use instrument
fl ight rules (IFR).
Visual meteorological conditions (VMC). Meteorological
conditions expressed in terms of visibility, distance from
cloud, and ceiling meeting or exceeding the minimums
specifi ed for VFR.
VMC. See visual meteorological conditions.
VOR. See very-high frequency omnidirectional range.
VORTAC. A facility consisting of two components, VOR
and TACAN, which provides three individual services: VOR
azimuth, TACAN azimuth, and TACAN distance (DME) at
one site.
VOR test facility (VOT). A ground facility which emits a
test signal to check VOR receiver accuracy. Some VOTs are
available to the user while airborne, while others are limited
to ground use only.
VOT. See VOR test facility.
VSI. See vertical speed indicator.
WAAS. See wide area augmentation system.
Warning area. An area containing hazards to any aircraft
not participating in the activities being conducted in the
area. Warning areas may contain intensive military training,
gunnery exercises, or special weapons testing.
Waypoint. A designated geographical location used for route
defi nition or progress-reporting purposes and is defi ned in
terms of latitude/longitude coordinates.
WCA. See wind correction angle.
Weather and radar processor (WARP). A device that
provides real-time, accurate, predictive and strategic weather
information presented in an integrated manner in the National
Airspace System (NAS).
Weight. The force exerted by an aircraft from the pull of
gravity.
Wide area augmentation system (WAAS). A differential
global positioning system (DGPS) that improves the accuracy
of the system by determining position error from the GPS
satellites, then transmitting the error, or corrective factors,
to the airborne GPS receiver.
Wind correction angle (WCA). The angle between the
desired track and the heading of the aircraft necessary to
keep the aircraft tracking over the desired track.
Work. A measurement of force used to produce movement.
Zone of confusion. Volume of space above the station where
a lack of adequate navigation signal directly above the VOR
station causes the needle to deviate.
I-1
A
above ground level .............................3-31, 7-44, 8-2, 9-10
absolute accuracy .........................................................7-25
acceleration in cruise fl ight ..........................................2-10
acute fatigue .............................................. 1-11, 1-12, 1-13
additional reports .........................................................10-7
adjust ............................................................................4-20
advanced technologies .................................................7-26
advanced technology systems ......................................3-28
adverse yaw ........................................................ 2-11, 2-12
aeronautical decision-making (ADM) 1-1, 1-12, 1-15, 1-17
aeronautical information manual (AIM) .............. 9-4, 10-2
agonic line ....................................................................3-12
air data computer (ADC) .............................................3-22
air route surveillance radar (ARSR) .................... 7-49, 9-7
air route traffi c control center (ARTC) 7-50, 9-4, 9-7, 10-2
air traffi c control (ATC) .............................. 1-15, 9-1, 11-1
infl ight weather avoidance assistance ......................9-11
radar weather displays ..............................................9-11
air traffi c control radar beacon system (ATCRBS) ......7-49
air traffi c control towers .................................................9-5
aircraft approach categories .........................................8-23
aircraft control ................................................................6-3
aircraft system malfunctions ........................................11-3
airplane trim ...................................................................4-8
airport diagram .............................................................8-27
airport information .........................................................8-6
airport sketch ................................................................8-27
airport surface detection equipment (ASDE) ..... 7-49, 7-50
airport surveillance radar (ASR) .......................... 7-49, 9-7
Airport/Facility Directory (A/FD) .......1-9, 7-10, 8-6, 10-2
airspace classifi cation .....................................................8-1
class A through G .......................................................8-2
airspeed color codes .....................................................3-10
airspeed
indicated .....................................................................3-9
indicator ..............................................4-6, 5-5, 5-37, 6-5
calibrated ....................................................................3-9
equivalent ...................................................................3-9
true ..............................................................................3-9
Index
airspeed changes
common errors ..........................................................6-10
airspeed indicators .................................... 4-26, 5-29, 5-61
maximum allowable airspeed ...................................3-10
alcohol ..........................................................................1-12
alternate airport ............................................................8-27
alternator/generator failure ...........................................11-5
altimeter ............................................................... 5-36, 6-4
amendment status .........................................................8-12
analog pictorial displays ..............................................3-22
anti-ice ..........................................................................2-12
approach lighting systems (ALS ..................................7-40
approach to stall ...........................................................5-26
altimeter
errors ...........................................................................3-4
cold weather ...............................................................3-5
enhancements (encoding) ...........................................3-7
analog instrument failure .............................................11-6
angle of attack ........................................................ 2-2, 2-6
approach azimuth guidance ..........................................7-45
approach control advances ...........................................9-12
approach control facility ..............................................9-12
approach to airport
without an operating control tower ........................10-14
with control tower, no approach control ................10-14
with control tower and approach control ................10-14
approaches ..................................................................10-12
missed .....................................................................10-21
parallel runways .....................................................10-20
radar ........................................................................10-17
timed, from a holding fi x ........................................10-18
area navigation (RNAV) ..............................................7-19
arrival .........................................................................10-33
atmosphere .....................................................................2-4
layers of the atmosphere .............................................2-5
attitude and heading reference system (AHRS) ...........3-22
attitude director indicator (ADI) ..................................3-23
I-2
attitude
indicator ....... 4-4, 4-5, 4-7, 5-2, 5-6, 5-34, 5-37, 6-3, 6-5
control .........................................................................4-3
instrument fl ying ....................................... 4-1, 4-21, 6-1
autokinesis ......................................................................1-7
automated fl ight service stations (AFSS) .......................9-4
automated radar terminal systems (ARTS) ....................9-7
automated surface observing station (ASOS) ..............8-10
automated terminal information service (ATIS) ..........10-8
automated weather observing station (AWOS) ...........8-10
automatic dependent surveillance-broadcast (ADS-B) 3-28
automatic direction fi nder (ADF) ................ 3-16, 7-3, 10-7
function of ..................................................................7-4
operational errors ........................................................7-8
automatic terminal information service (ATIS) . 1-15, 8-16
automatic weather observing system (AWOS) ..............7-3
autopilot systems ..........................................................3-24
autorotations .................................................................6-17
common errors ....................................................6-17
azimuth card ...................................................................7-4
B
back courses (BC) ........................................................7-39
bank control .......................... 4-4, 4-7, 4-20, 5-6, 5-37, 6-5
baro-aiding ...................................................................7-28
barometric vertical navigation (BARO VNAV) ..........8-32
basic aerodynamics (review of) .....................................2-2
relative wind ...............................................................2-2
angle of attack ............................................................2-2
basic instrument fl ight patterns .......................... 5-30, 5-61
basic radio principles .....................................................7-2
blockage considerations .................................................3-2
indications of pitot tube blockage ..............................3-3
indications from static port blockage .........................3-3
effects of fl ight conditions ..........................................3-3
C
calibrated .............................................................. 5-2, 6-14
calibrated orifi ce .............................................................3-8
center approach/departure control ..................................9-7
certifi ed checkpoints ....................................................7-16
changeover points (COPs) ...........................................8-10
changing technology ....................................................6-18
charted IFR altitudes ......................................................8-6
chronic fatigue .............................................................1-13
circling approaches ....................................................10-20
circling approach pattern ..............................................5-32
class D airspace ...................................................... 8-2, 9-6
clean confi guration .......................................................5-11
clear ice ............................................................ 2-13, 10-24
clearances .....................................................................10-3
separations ................................................................10-4
clearance delivery ........................................................10-4
clearance on request .......................................................9-6
clearance void time ........................................................9-5
climbing
while accelerating .......................................................1-8
while turning ..............................................................1-8
climbs ................................................................. 2-10, 5-14
common errors
fi xation ......................................................................4-27
omission ...................................................................4-28
emphasis ...................................................................4-28
communication equipment .............................................9-2
communication facilities ................................................9-4
communication procedures ............................................9-4
communication/navigation system malfunction ..........11-8
compass
course .......................................................................3-13
locator ............................................................. 7-28, 7-40
turns ....................................................... 5-21, 5-53, 6-15
compass rose ...................................................... 3-12, 5-25
computer navigation fi x ...............................................8-10
concentric rings ............................................................8-18
conducting an IFR fl ight ............................................10-27
constant airspeed climb
from cruise airspeed .................................................5-46
from established airspeed .........................................5-47
constant rate climbs ......................................................5-47
control
characteristics .............................................................2-7
and performance .........................................................4-2
instruments ....................................................... 4-2, 4-18
sequence ...................................................................9-13
control display unit (CDU) ..........................................3-26
control pressures ............................................................5-3
coordinated ............................................................. 5-6, 6-5
coordination of rudder and aileron controls .................2-11
coriolis illusion...............................................................1-6
course interception .......................................................7-14
course reversal elements
plan view ..................................................................8-20
profi le view ...............................................................8-20
crew resource management (CRM) .............................1-14
critical areas ...................................................................7-2
cross-check ........................................................... 4-3, 4-20
common errors ..........................................................4-11
cruise clearance ............................................................10-4
current induction ..........................................................3-15
I-3
D
dark adaptation ...............................................................1-3
DECIDE model ............................................................1-17
decision height (DH) ................................. 3-31, 7-50, 8-21
deice .............................................................................2-13
density altitude ...............................................................2-5
departure ....................................................................10-31
departure procedures (DPs) ................7-1, 7-33, 8-12, 10-5
instrument .................................................................7-33
departures
airports without an operating control tower .............10-7
radar controlled ........................................................10-5
descents .............................................................. 5-16, 5-49
deviation .......................................................................3-12
differential global positioning systems (DGPS) ..........7-34
direct indication ............................................ 5-2, 5-34, 6-3
directional ....................................................................7-42
distance circle ...............................................................8-18
distance measuring equipment (DME) ................ 7-16, 8-7
arc .............................................................................7-17
components ...............................................................7-17
errors .........................................................................7-19
function of ................................................................7-17
diving
or rolling beyond the vertical plane ............................1-8
while turning ..............................................................1-8
DOD .............................................................................3-22
doghouse ......................................................................3-21
domestic reduced vertical
separation minimum (DRVSM) ...........................3-7
double gimbal ...............................................................3-18
drag ................................................................................2-3
drag curves .....................................................................2-6
dry air vacuum pump ...................................................3-17
duplex .............................................................................9-2
dynamic pressure type instruments ................................3-8
E
ears .................................................................................1-4
otolith organs .................................................. 1-4, 1-5
semicircular canals .................................................1-4
eddy currents ........................................................ 2-3, 3-14
electrical systems .........................................................3-18
electronic fl ight display (EFD) .......................................4-1
electronic fl ight instrument systems .............................3-27
elevator illusion ..............................................................1-6
emergencies ..................................................................6-16
en route ............................................................. 10-7, 10-32
en route fl ight advisory service (EFAS) .........................9-4
en route high-altitude charts ...........................................8-6
en route procedures ......................................................10-7
encoding altimeter ..........................................................3-7
entry .................................................5-14, 5-46, 5-49, 6-10
equipment .....................................................................1-14
eyes ................................................................................1-2
F
false horizon ...................................................................1-7
fatigue ..........................................................................1-12
featureless terrain illusion ..............................................1-9
federal airways ...............................................................8-4
feeder facilities .............................................................8-18
feet per minute (fpm) .....................................................4-6
fi ling in fl ight ...............................................................10-2
fi nal approach fi x (FAF) ...............................................7-23
fi nal approach waypoint (FAWP) ................................7-32
fl ight director indicator (FDI) ......................................3-23
fl ight instruments .......................................... 2-16, 3-1, 6-2
fl ight levels (FL) ............................................................3-7
fl ight management systems (FMS) ..............................3-25
function of ................................................................7-48
fl ight patterns ...............................................................5-30
fl ight planning information, sources ............................10-2
fl ight strips .....................................................................9-5
fl ight support systems ..................................................3-22
fl ight path ............................................................... 2-2, 2-6
four step process used to change attitude .....................4-20
fl ux gate compass .........................................................3-14
fl ying experience ........................................................10-22
fog ...................................................................... 1-9, 10-24
form drag ........................................................................2-4
four forces ......................................................................2-2
fundamental skills
of attitude instrument fl ying .....................................4-24
instrument cross-check .............................................4-10
instrument fl ight .........................................................6-2
G
glide slope ....................................................................7-39
glide slope intercept altitude ......................................10-20
global landing system (GLS) .......................................8-32
global navigation satellite system (GNSS) ..................7-26
global positioning system (GPS) ....................... 3-27, 7-27
components ...............................................................7-27
errors .........................................................................7-33
familiarization ..........................................................7-34
function of ................................................................7-28
instrument approaches ..............................................7-31
nearest airport function .............................................11-9
substitution ...............................................................7-28
graveyard spiral ..............................................................1-6
ground lighting illusions ................................................1-9
I-4
ground proximity warning system (GPWS) ................3-34
ground speed ................................................................7-19
ground wave ...................................................................7-2
gyroscopic systems, power sources .............................3-16
pneumatic systems ....................................................3-16
vacuum pump systems .............................................3-17
gyroscopic instruments
attitude indicator .......................................................3-18
H
hazard identifi cation .....................................................1-13
hazardous attitudes .......................................................1-18
and antidotes .............................................................1-18
Hazardous Infl ight Weather Advisory Service
(HIWAS) ......................................................................8-10
haze ................................................................................1-9
head up display (HUD) ...................................... 3-34, 7-49
heading ............................................................... 5-13, 5-44
heading indicators ........................ 3-19, 4-7, 5-7, 5-38, 6-6
height above airport (HAA) .........................................8-27
height above landing (HAL) ........................................8-27
height above threshold elevation (HAT) ......................8-27
helicopter trim ..............................................................4-10
holding .........................................................................10-9
DME .......................................................................10-13
instructions .............................................................10-10
patterns .......................................................................7-1
procedures ..............................................................10-10
homing ...........................................................................7-5
horizontal situation indicator (HSI) ................... 3-22, 5-38
human
factors .........................................................................1-1
resources ...................................................................1-14
I
IAP minimums ...........................................................10-21
ICAO cold temperature error table ................................3-6
ICAO Standard Atmosphere ..........................................2-5
icing ..............................................................................2-12
types of .....................................................................2-13
identifying intersections .................................................8-7
IFR en route and terminal operations ...........................7-28
IFR en route charts .........................................................8-6
IFR fl ight plan ..............................................................10-2
canceling ...................................................................10-3
IFR Flight using GPS ...................................................7-30
illusions leading to spatial disorientation .......................1-5
IMSAFE Checklist .......................................................1-13
indirect indication ........................................... 5-3, 5-6, 6-4
induced drag ...................................................................2-3
induction icing .............................................................2-13
inertia navigation systems (INS) ..................................7-36
components ...............................................................7-37
errors .........................................................................7-37
initial approach fi x (IAF) .......................... 7-23, 8-16, 8-18
inoperative components ...............................................8-27
instantaneous vertical speed indicator (IVSI) ........ 3-8, 4-6
instrument
approach capabilities ................................................7-36
approach systems ......................................................7-37
cross-check .............................................. 4-10, 4-24, 6-2
instrument approach procedures (IAPs) ...... 7-17, 8-2, 8-12
instrument approach procedures, compliance with ....10-12
instrument approaches
to civil airports .......................................................10-13
radar monitoring of .................................................10-18
instrument fl ight .............................................................6-2
instrument fl ight rules (IFR) ................................ 3-1, 10-1
instrument interpretation ................................................6-3
instrument landing systems (ILS) ................................7-37
components ...............................................................7-39
errors .........................................................................7-44
function .....................................................................7-42
instrument takeoffs .................................... 5-29, 5-60, 6-17
common errors ....................................... 5-29, 5-61, 6-18
instrument weather fl ying ..........................................10-22
integrated fl ight control system ....................................3-24
intercepting lead radials ...............................................7-19
interference drag ............................................................2-3
international civil aviation organization (ICAO) ... 2-5, 8-1
international standard atmosphere (ISA) .......................2-5
inversion illusion ............................................................1-6
inverted-V cross-check ................................................4-11
inverter .........................................................................3-18
isogonic lines ...............................................................3-12
J
jet routes .........................................................................8-5
K
Kollsman window .................................................. 3-4, 9-3
L
lag ........................................................................... 5-5, 6-5
land as soon as possible ...............................................6-17
land as soon as practical ...............................................6-17
land immediately ..........................................................6-17
landing ........................................................................10-22
landing minimums .......................................................8-23
large airplanes ..............................................................2-10
Law of Inertia .................................................................2-9
I-5
Law of Momentum ........................................................2-4
Law of Reaction .............................................................2-4
layers of the atmosphere ................................................2-5
lead radial .....................................................................7-19
leans, the ........................................................................1-5
learning methods
control and performance ................................... 4-2, 4-17
primary and supporting ..............................................4-2
letters of agreement (LOA) ..........................................9-14
leveling off .......................................5-16, 5-17, 5-48, 5-50
lift ........................................................................... 2-2, 2-6
lines of magnetic fl ux ...................................................3-11
load factor ....................................................................2-11
local area augmentation system (LAAS) ........... 7-36, 8-32
localizer (LOC) ............................................................7-39
localizer type directional aid (LDA) ............................7-45
long range navigation (LORAN) ......................... 7-3, 7-24
components ...............................................................7-25
errors .........................................................................7-26
function of ................................................................7-26
loss of alternator/generator for electronic fl ight
instrumentation ............................................................11-5
lubber line ....................................................................3-11
M
mach number ................................................................3-10
machmeters ..................................................................3-10
magnetic compass, basic aviation ................................3-11
induced errors ...........................................................3-12
magnetic bearing (MB) ..................................................7-3
magnetic heading (MH) .................................................7-3
magnetism ....................................................................3-10
margin identifi cation ....................................................8-12
marker beacons ......................................... 7-37, 7-40, 7-44
maximum authorized altitude (MAA) ...........................8-7
mean sea level (MSL) ..................................................10-9
medical factors .............................................................1-12
acute fatigue..............................................................1-12
alcohol ......................................................................1-12
chronic fatigue ..........................................................1-13
fatigue .......................................................................1-12
microwave landing system (MLS) ...............................7-45
middle markers (MMs) ................................................7-39
mileage breakdown ......................................................8-10
military operations areas (MOAs) .................................8-4
military training routes (MTRs) .....................................8-4
minimum crossing altitude (MCA) ................................8-7
minimum descent altitude (MDA) ..................... 7-32, 8-21
minimum en route altitude (MEA) ................................8-6
minimum obstruction clearance altitude (MOCA) ........8-6
minimum reception altitude (MRA) ..............................8-6
minimum safe altitude (MSA) ........................... 8-16, 8-18
minimum vectoring altitudes (MVAs) ...........................9-6
minimums section ........................................................8-23
missed approach point (MAP) .....................................7-23
missed approach procedure ..........................................8-23
missed approach waypoint (MAHWP) ........................7-32
mixed ice ......................................................................2-14
Mode C...........................................................................3-7
altitude reporting ........................................................9-3
models for practicing ADM
perceive, process, perform .......................................1-17
DECIDE model, the .................................................1-17
monopulse secondary surveillance radar (MSSR) .......9-12
multi-function display (MFD) ................. 3-27, 3-28, 11-12
navigating page groups ...........................................11-10
nearest airports, using .............................................11-10
N
National Aeronautical Charting Group (NACG) ...........8-2
National Airspace System (NAS) .......................... 8-1, 9-1
National Security Areas (NSA) .....................................8-4
National Transportation Safety Board (NTSB .............2-16
nautical miles (NM) .....................................................7-17
navigation/communication (NAV/COM) equipment .........
................................................................................ 9-2, 9-3
navigation features .........................................................8-7
navigation instruments ......................................... 4-2, 4-19
nearest airport page group ..........................................11-10
nearest airports page soft keys ...................................11-10
nerves .............................................................................1-5
new technologies ..........................................................8-10
Newton’s First Law of Motion Law of Inertia ...............2-4
Newton’s Second Law of Motion Law of Momentum ..2-4
Newton’s Third Law of Motion Law of Reaction .........2-4
no-gyro approach .......................................................10-18
nondirectional beacon (NDB) ................................ 7-3, 8-7
nonprecision approach ...................................................9-7
nonstandard pressure on an altimeter .............................3-6
normal command ...........................................................2-7
North American Route Program (NRP) .........................8-6
nose high attitudes ........................................................5-27
nose low attitudes .........................................................5-28
notices to airmen (NOTAM) ................................ 7-10, 8-4
O
obstical clearance surface ............................................7-32
obstacle departure procedures (ODP) ..........................8-12
off-route obstruction clearance altitude (OROCA .........8-6
operating on the main battery ......................................11-5
operational errors .........................................................7-45
optical illusions ..............................................................1-9
I-6
featureless terrain illusion ..........................................1-9
fog ...............................................................................1-9
ground lighting illusions .............................................1-9
haze .............................................................................1-9
how to prevent landing errors due to optical illusions ....
....................................................................................1-9
runway width illusion .................................................1-9
runway and terrain slopes illusion ..............................1-9
water refraction ..........................................................1-9
orientation ......................................................................1-2
oscillation error ............................................................3-14
otolith organs ......................................................... 1-4, 1-5
outer markers (OMs) ....................................................7-39
outside air temperature (OAT) .....................................11-2
overcontrolling ................................................ 4-7, 5-4, 6-3
overpower ......................................................................5-9
P
parasite drag ...................................................................2-3
partial panel fl ight ........................................................5-36
performance instruments ...................................... 4-2, 4-19
physiological and psychological factors ......................1-11
pilot briefi ng .................................................................8-12
Pilot’s Operating Handbook/Airplane Flight
Manual (POH/AFM) ......................................................3-3
pilot/static instruments ...................................................3-3
pilot/static systems .........................................................3-2
failure .......................................................................11-7
pitch control ............................ 4-4, 4-20-21, 5-2, 5-34, 6-3
pitch/power relationship .................................................2-6
pitot pressure ..................................................................3-2
pitot-static head ..............................................................3-2
plan view ......................................................................8-16
course reversal elements ...........................................8-20
planning the descent and approach ..............................10-8
prefl ight ........................................................................10-2
profi le view ..................................................................8-21
pneumatic systems .......................................................3-16
failure .......................................................................11-7
POH/AFM ....................................................................10-2
position
error ............................................................................3-3
reports .......................................................................10-7
postural considerations ...................................................1-7
power ................................................2-10, 5-13, 5-25, 5-45
control ....................................... 4-4, 4-8, 4-21, 5-8, 5-39
settings .............................................................. 5-9, 5-39
precession .....................................................................3-16
error .................................................................... 5-7, 6-6
precipitation static (P-static) ........................................11-3
precision approach .......................................................7-37
precision approach path indicator (PAPI) ....................1-10
precision approach radar (PAR) ....................... 7-49, 10-17
precision runway monitor (PRM) ................................9-12
RADAR ....................................................................9-12
benefi ts .....................................................................9-12
preferred IFR routes .......................................................8-5
pressure
altitude ................................................................ 2-5, 9-3
density ........................................................................2-5
indicating systems ....................................................3-18
preventing landing errors due to optical illusions ..........1-9
primary
bank ..........................................................................4-23
pitch ..........................................................................4-22
power ........................................................................4-23
yaw ...........................................................................4-23
primary and supporting method ........................... 4-4, 4-21
primary fl ight display (PFD) ........................................3-27
additional information for specifi c airport .............11-11
nearest airports, using .............................................11-10
procedure turn .................................................... 7-32, 8-20
holding in lieu of ......................................................8-20
standard 45° ..............................................................5-30
80/260 .......................................................................5-31
profi le view ..................................................................8-21
propeller icing ..............................................................2-16
propeller/rotor modulation error ....................................7-2
R
racetrack pattern ...........................................................5-30
radar ..............................................................................9-3
limitations .................................................................7-50
transponders ...............................................................9-3
radar controlled departures ..........................................10-5
radar navigation (ground based) ..................................7-49
functions of ...............................................................7-49
radials ...........................................................................7-10
radio altimeter ..............................................................3-30
radio frequency (RF .....................................................7-16
radio magnetic indicator (RMI) ........................... 3-15, 7-4
radio wave ......................................................................7-2
radius of turn ................................................................2-11
rate of turns ..................................................................2-10
receiver autonomous integrity monitoring (RAIM) .....7-28
receiver-transmitter (RT) .............................................3-31
rectangular cross-check ................................................4-11
reduced vertical separation minimum (RVSM) .............3-7
reference circle .............................................................8-18
I-7
regions of command .......................................................2-7
normal command ........................................................2-7
reversed command ......................................................2-8
relative bearing (RB) ......................................................7-3
relative wind ........................................................... 2-2, 2-4
remote communications outlet (RCO) .........................8-10
remote indicating compass ...........................................3-15
repeatable accuracy ......................................................7-25
required navigation performance .................................7-46
required navigation instrument system inspection .......3-34
reversal of motion ..........................................................1-8
RNAV instrument approach charts ..............................8-32
reversed command .........................................................2-8
reverse sensing .............................................................7-12
rhodopsin........................................................................1-2
rigidity ..........................................................................3-16
rime ice .........................................................................2-13
risk................................................................................1-13
risk analysis ..................................................................1-13
RNAV (See area navigation) runway width
illusion ................................................................. 1-9, 1-10
and terrain slopes illusion ................................. 1-9, 1-10
runway end identifi er lights (REIL) .............................7-40
runway visual range (RVR) ............................. 8-27, 10-22
runway visual value (RVV) .......................................10-22
S
safety systems ..............................................................3-30
scanning techniques .....................................................4-24
selected radial cross-check ................................. 4-11, 4-24
selective availability (SA) ............................................7-33
semicircular canals .........................................................1-4
sensitive altimeter ..........................................................3-3
principle of operation .................................................3-3
sensory systems for orientation ......................................1-2
servo failure .................................................................6-17
side-step maneuver .....................................................10-20
simplex ...........................................................................9-2
simplifi ed directional facility (SDF) ............................7-45
single-pilot resource management (SRM) ...................1-14
situational awareness ....................................... 1-14, 11-11
skin friction drag ............................................................2-3
sky wave .........................................................................7-2
slip/skid indicator .........................................................5-39
slow-speed fl ight ............................................................2-8
small airplanes ...............................................................2-9
somatogravic illusion .....................................................1-6
space wave .....................................................................7-2
spatial disorientation ......................................................1-2
coping with spatial disorientation ..............................1-8
demonstration of spatial disorientation ......................1-7
special use airspace ........................................................8-2
speed stability .................................................................2-7
St. Elmo’s Fire ..................................................... 7-3, 11-3
stall warning systems ...................................................2-16
standard entry procedures ..........................................10-11
standard holding pattern
no wind .....................................................................10-9
with wind ..................................................................10-9
standard instrument departure procedures (SID) .........10-5
standard rate of turn .................................. 2-11, 5-19, 5-51
establishing ...............................................................5-51
common errors ..........................................................5-51
standard terminal arrival routes (STAR) ............ 8-12, 10-9
standby battery .............................................................11-6
static longitudinal stability .............................................2-8
static pressure .................................................................3-2
steep turns .......................................................... 5-22, 5-53
stepdown fi xes ..............................................................8-21
straight-and-level fl ight ........................4-22, 5-2, 5-34, 6-3
airspeed changes ............................................. 5-11, 5-40
common errors ............................................................6-7
power control during ..................................................6-7
straight climbs and descents ............................... 5-14, 5-46
common errors ....................................... 5-17, 5-50, 6-13
stress .............................................................................1-11
structural icing ................................................ 2-13, 10-24
suction relief valve .......................................................3-17
synchro .........................................................................3-15
synthetic vision ............................................................3-27
system status ................................................................7-33
systems prefl ight procedures
before engine start ....................................................3-36
after engine start .......................................................3-37
taxiing and takeoff ....................................................3-37
engine shut down ......................................................3-37
T
tactical air navigation (TACAN) .................. 7-8, 8-7, 10-7
tailplane stall symptoms ...............................................2-16
task management ..........................................................1-15
teardrop
patterns .....................................................................5-31
procedure ..................................................................8-21
techniques ......................................................................5-1
for electrical usage ......................................... 11-5, 11-6
master battery switch ................................................11-5
operating on the main battery ......................... 11-5, 11-6
temporary fl ight restrictions (TFRs) ..............................8-4
tension ................................................................ 4-10, 4-13
terminal arrival area (TAA) .........................................8-18
terminal instrument approach procedures (TERPs) .....8-12
I-8
Terminal Procedures Publications (TPP) .....................8-12
terminal radar approach control (TRACON) .................9-6
terrain alerting systems ................................................3-34
terrain awareness and warning systems (TAWS) ........3-34
threshold crossing height (TCH) ..................................8-32
thrust ......................................................2-2, 2-3, 2-6, 2-10
thunderstorm encounter, inadvertent ...........................11-2
thunderstorms ................................................... 9-11, 10-25
tilting to right or left .......................................................1-8
time factors .................................................................10-12
time and speed table .....................................................8-27
timed turns ................................................ 5-21, 5-53, 6-13
Title 14 of the Code of Federal Regulations
(14 CFR) ..................1-12, 3-2, 7-16, 8-4, 8-11, 10-2, 11-8
touch down zone elevation (TDZE) .............................8-27
Tower En Route Control (TEC) ............................. 8-6, 9-7
tracking ..........................................................................7-5
to and from the station ..............................................7-14
Traditional navigation systems ......................................7-3
traffi c
advisory systems ......................................................3-31
alert systems .............................................................3-31
alert and collision avoidance system (TCAS) ..........3-31
avoidance ................................................................11-14
avoidance systems ....................................................3-31
information system (TIS) .........................................3-31
transcribed weather broadcast (TWEB) .......................8-10
transponder .....................................................................9-3
codes ...........................................................................9-3
trend indicators .............................................................4-26
trim ................. 2-8, 4-8, 4-10, 4-20, 5-12, 5-13, 5-26, 5-45
control ............................................................... 4-8, 5-43
turbulence ...................................................................10-23
turn indicator ........................................................ 3-20, 6-7
turn rate indicator .........................................................5-38
turn-and-slip indicator .......................................... 3-20, 5-8
turns..................................................2-10, 5-19, 5-51, 6-13
change of airspeed .......................................... 5-24, 6-14
climbing and descending ................................ 5-24, 6-15
common errors ................................................ 5-25, 6-15
compass ................................................. 5-21, 5-53, 6-15
coordinator ................................................ 3-21, 4-8, 5-7
to predetermined headings .................... 5-20, 5-52, 6-13
radius of ....................................................................2-11
rate of ........................................................................2-10
standard rate .......................................... 2-11, 5-19, 5-51
steep ..........................................................................5-22
timed ...................................................... 5-21, 5-53, 6-13
turn-and-slip indicator ................................... 3-20, 4-8, 5-8
types of icing ................................................................2-13
types of NAVAIDS ........................................................8-7
U
ultra high frequency (UHF) ...........................................7-3
uncaging .......................................................................5-29
underpower ..................................................................5-39
unforecast adverse weather ..........................................11-2
unusual attitude .................................................. 5-26, 6-16
common errors ....................................... 5-28, 5-58, 6-16
recognizing ...............................................................5-27
recovery from ................................................. 5-26, 5-55
V
vacuum pump systems .................................................3-17
variation .......................................................................3-12
vectoring ........................................................................9-6
venturi tubes .................................................................3-16
vertical card magnetic compass ...................................3-14
vertical speed indicator (VSI) ..................3-8, 4-5, 5-4, 6-5
very high frequency (VHF) ............................................9-2
very high frequency omni-directional
range (VOR) ...................................................................7-8
accuracy ....................................................................7-16
function of ................................................................7-12
operational errors ......................................................7-14
receiver accuracy check ...........................................7-16
vestibular ......................................................... 1-2, 1-4, 1-5
vestibular illusions .........................................................1-5
VFR Over-The-Top ...................................................10-27
VFR-On-Top ..............................................................10-26
Victor airways ................................................................8-4
visual approach slope indicator (VASI) .......................7-41
visual descent point (VDP) ..........................................8-21
visual fl ight rules (VFR) ........................2-1, 3-1, 4-16, 6-1
visual illusions ...............................................................1-7
visual meteorological conditions
(VMC) ................................................1-3, 7-31, 7-34, 9-14
volcanic ash ................................................................10-24
VOR/DME RNAV .......................................................7-23
components ...............................................................7-23
errors .........................................................................7-24
function of ................................................................7-23
VOR test facility (VOT) ..............................................7-16
VMC (See visual meteorological conditions)
W
water refraction ..............................................................1-9
waypoint .........................................................................7-8
weather and radar processor (WARP) .........................9-11
weather avoidance assistance .......................................9-11
weather conditions .....................................................10-22
weather information and communication features .......8-10
I-9
weight ..................................................................... 2-2, 2-3
wet type vacuum pump ................................................3-17
wide area augmentation system (WAAS) ....................7-34
windshields ........................................................ 2-16, 2-17
wing, the .........................................................................2-2
wind correction angle (WCA) ........................................7-5
wind shear ..................................................................10-25
work .............................................................................2-10
Z
zone of confusion .........................................................7-12
