2-1-7. Pilot Control of Airport Lighting
Radio control of lighting is available at selected
airports to provide airborne control of lights by
keying the aircraft's microphone. Control of lighting
systems is often available at locations without
specified hours for lighting and where there is no
control tower or FSS or when the tower or FSS is
closed (locations with a part-time tower or FSS) or
specified hours. All lighting systems which are radio
controlled at an airport, whether on a single runway
or multiple runways, operate on the same radio
frequency. (See TBL 2-1-1 and TBL 2-1-2.)
AIM 2/14/08
2-1-7
Airport Lighting Aids
FIG 2-1-9
Taxiway Lead-On Light Configuration
TBL 2-1-1
Runways With Approach Lights
Lighting System
No. of Int.
Steps
Status During
Nonuse Period
Intensity Step Selected Per No. of Mike Clicks
3 Clicks 5 Clicks 7 Clicks
Approach Lights (Med. Int.) 2 Off Low Low High
Approach Lights (Med. Int.) 3 Off Low Med High
MIRL 3 Off or Low _ _ _
HIRL 5 Off or Low _ _ _
VASI 2 Off _ _ _
NOTES: _ Predetermined intensity step.
_ Low intensity for night use. High intensity for day use as determined by photocell control.
TBL 2-1-2
Runways Without Approach Lights
Lighting System
No. of Int.
Steps
Status During
Nonuse Period
Intensity Step Selected Per No. of Mike Clicks
3 Clicks 5 Clicks 7 Clicks
MIRL 3 Off or Low Low Med. High
HIRL 5 Off or Low Step 1 or 2 Step 3 Step 5
LIRL 1 Off On On On
VASI_ 2 Off _ _ _
REIL_ 1 Off Off On/Off On
REIL_ 3 Off Low Med. High
NOTES: _ Low intensity for night use. High intensity for day use as determined by photocell control.
_ The control of VASI and/or REIL may be independent of other lighting systems.
AIM 2/14/08
2-1-8 Airport Lighting Aids
a. With FAA approved systems, various combina-
tions of medium intensity approach lights, runway
lights, taxiway lights, VASI and/or REIL may be
activated by radio control. On runways with both
approach lighting and runway lighting (runway edge
lights, taxiway lights, etc.) systems, the approach
lighting system takes precedence for air-to-ground
radio control over the runway lighting system which
is set at a predetermined intensity step, based on
expected visibility conditions. Runways without
approach lighting may provide radio controlled
intensity adjustments of runway edge lights. Other
lighting systems, including VASI, REIL, and taxiway
lights may be either controlled with the runway edge
lights or controlled independently of the runway edge
lights.
b. The control system consists of a 3-step control
responsive to 7, 5, and/or 3 microphone clicks. This
3-step control will turn on lighting facilities capable
of either 3-step, 2-step or 1-step operation. The
3-step and 2-step lighting facilities can be altered in
intensity, while the 1-step cannot. All lighting is
illuminated for a period of 15 minutes from the most
recent time of activation and may not be extinguished
prior to end of the 15 minute period (except for 1-step
and 2-step REILs which may be turned off when
desired by keying the mike 5 or 3 times respectively).
c. Suggested use is to always initially key the mike
7 times; this assures that all controlled lights are
turned on to the maximum available intensity. If
desired, adjustment can then be made, where the
capability is provided, to a lower intensity (or the
REIL turned off) by keying 5 and/or 3 times. Due to
the close proximity of airports using the same
frequency, radio controlled lighting receivers may be
set at a low sensitivity requiring the aircraft to be
relatively close to activate the system. Consequently,
even when lights are on, always key mike as directed
when overflying an airport of intended landing or just
prior to entering the final segment of an approach.
This will assure the aircraft is close enough to activate
the system and a full 15 minutes lighting duration is
available. Approved lighting systems may be
activated by keying the mike (within 5 seconds) as
indicated in TBL 2-1-3.
TBL 2-1-3
Radio Control System
Key Mike Function
7 times within 5 seconds Highest intensity available
5 times within 5 seconds Medium or lower intensity
(Lower REIL or REIL-off)
3 times within 5 seconds Lowest intensity available
(Lower REIL or REIL-off)
d. For all public use airports with FAA standard
systems the Airport/Facility Directory contains the
types of lighting, runway and the frequency that is
used to activate the system. Airports with IAPs
include data on the approach chart identifying the
light system, the runway on which they are installed,
and the frequency that is used to activate the system.
NOTE-
Although the CTAF is used to activate the lights at many
airports, other frequencies may also be used. The
appropriate frequency for activating the lights on the
airport is provided in the Airport/Facility Directory and
the standard instrument approach procedures publica-
tions. It is not identified on the sectional charts.
e. Where the airport is not served by an IAP, it may
have either the standard FAA approved control
system or an independent type system of different
specification installed by the airport sponsor. The
Airport/Facility Directory contains descriptions of
pilot controlled lighting systems for each airport
having other than FAA approved systems, and
explains the type lights, method of control, and
operating frequency in clear text.
2-1-8. Airport/Heliport Beacons
a. Airport and heliport beacons have a vertical
light distribution to make them most effective from
one to ten degrees above the horizon; however, they
can be seen well above and below this peak spread.
The beacon may be an omnidirectional capacitor-dis-
charge device, or it may rotate at a constant speed
which produces the visual effect of flashes at regular
intervals. Flashes may be one or two colors
alternately. The total number of flashes are:
1. 24 to 30 per minute for beacons marking
airports, landmarks, and points on Federal airways.
2. 30 to 45 per minute for beacons marking
heliports.
AIM 2/14/08
2-1-9
Airport Lighting Aids
b. The colors and color combinations of beacons
are:
1. White and Green- Lighted land airport.
2. *Green alone- Lighted land airport.
3. White and Yellow- Lighted water airport.
4. *Yellow alone- Lighted water airport.
5. Green, Yellow, and White- Lighted heliport.
NOTE*Green alone or yellow alone is used only in connection
with a white-and-green or white-and-yellow beacon
display, respectively.
c. Military airport beacons flash alternately white
and green, but are differentiated from civil beacons
by dualpeaked (two quick) white flashes between the
green flashes.
d. In Class B, Class C, Class D and Class E surface
areas, operation of the airport beacon during the hours
of daylight often indicates that the ground visibility
is less than 3 miles and/or the ceiling is less than
1,000_feet. ATC clearance in accordance with
14_CFR Part 91 is required for landing, takeoff and
flight in the traffic pattern. Pilots should not rely
solely on the operation of the airport beacon to
indicate if weather conditions are IFR or VFR. At
some locations with operating control towers, ATC
personnel turn the beacon on or off when controls are
in the tower. At many airports the airport beacon is
turned on by a photoelectric cell or time clocks and
ATC personnel cannot control them. There is no
regulatory requirement for daylight operation and it
is the pilot's responsibility to comply with proper
preflight planning as required by 14 CFR
Section_91.103.
2-1-9. Taxiway Lights
a. Taxiway Edge Lights. Taxiway edge lights are
used to outline the edges of taxiways during periods
of darkness or restricted visibility conditions. These
fixtures emit blue light.
NOTE-
At most major airports these lights have variable intensity
settings and may be adjusted at pilot request or when
deemed necessary by the controller.
b. Taxiway Centerline Lights. Taxiway center-
line lights are used to facilitate ground traffic under
low visibility conditions. They are located along the
taxiway centerline in a straight line on straight
portions, on the centerline of curved portions, and
along designated taxiing paths in portions of
runways, ramp, and apron areas. Taxiway centerline
lights are steady burning and emit green light.
c. Clearance Bar Lights. Clearance bar lights
are installed at holding positions on taxiways in order
to increase the conspicuity of the holding position in
low visibility conditions. They may also be installed
to indicate the location of an intersecting taxiway
during periods of darkness. Clearance bars consist of
three in-pavement steady-burning yellow lights.
d. Runway Guard Lights. Runway guard lights
are installed at taxiway/runway intersections. They
are primarily used to enhance the conspicuity of
taxiway/runway intersections during low visibility
conditions, but may be used in all weather conditions.
Runway guard lights consist of either a pair of
elevated flashing yellow lights installed on either side
of the taxiway, or a row of in-pavement yellow lights
installed across the entire taxiway, at the runway
holding position marking.
NOTE-
Some airports may have a row of three or five in-pavement
yellow lights installed at taxiway/runway intersections.
They should not be confused with clearance bar lights
described in paragraph 2-1-9c, Clearance Bar Lights.
e. Stop Bar Lights. Stop bar lights, when
installed, are used to confirm the ATC clearance to
enter or cross the active runway in low visibility
conditions (below 1,200 ft Runway Visual Range). A
stop bar consists of a row of red, unidirectional,
steady-burning in-pavement lights installed across
the entire taxiway at the runway holding position, and
elevated steady-burning red lights on each side. A
controlled stop bar is operated in conjunction with the
taxiway centerline lead-on lights which extend from
the stop bar toward the runway. Following the ATC
clearance to proceed, the stop bar is turned off and the
lead-on lights are turned on. The stop bar and lead-on
lights are automatically reset by a sensor or backup
timer.
CAUTION-
Pilots should never cross a red illuminated stop bar, even
if an ATC clearance has been given to proceed onto or
across the runway.
NOTE-
If after crossing a stop bar, the taxiway centerline lead-on
lights inadvertently extinguish, pilots should hold their
position and contact ATC for further instructions.
AIM 2/14/08
2-2-1
Air Navigation and Obstruction Lighting
Section 2. Air Navigation and Obstruction Lighting
2-2-1. Aeronautical Light Beacons
a. An aeronautical light beacon is a visual
NAVAID displaying flashes of white and/or colored
light to indicate the location of an airport, a heliport,
a landmark, a certain point of a Federal airway in
mountainous terrain, or an obstruction. The light used
may be a rotating beacon or one or more flashing
lights. The flashing lights may be supplemented by
steady burning lights of lesser intensity.
b. The color or color combination displayed by a
particular beacon and/or its auxiliary lights tell
whether the beacon is indicating a landing place,
landmark, point of the Federal airways, or an
obstruction. Coded flashes of the auxiliary lights, if
employed, further identify the beacon site.
2-2-2. Code Beacons and Course Lights
a. Code Beacons. The code beacon, which can be
seen from all directions, is used to identify airports
and landmarks. The code beacon flashes the three or
four character airport identifier in International
Morse Code six to eight times per minute. Green
flashes are displayed for land airports while yellow
flashes indicate water airports.
b. Course Lights. The course light, which can be
seen clearly from only one direction, is used only with
rotating beacons of the Federal Airway System:
two_course lights, back to back, direct coded flashing
beams of light in either direction along the course of
airway.
NOTE-
Airway beacons are remnants of the “lighted” airways
which antedated the present electronically equipped
federal airways system. Only a few of these beacons exist
today to mark airway segments in remote mountain areas.
Flashes in Morse code identify the beacon site.
2-2-3. Obstruction Lights
a. Obstructions are marked/lighted to warn airmen
of their presence during daytime and nighttime
conditions. They may be marked/lighted in any of the
following combinations:
1. Aviation Red Obstruction Lights. Flash-
ing aviation red beacons (20 to 40 flashes per minute)
and steady burning aviation red lights during
nighttime operation. Aviation orange and white paint
is used for daytime marking.
2. Medium Intensity Flashing White
Obstruction Lights. Medium intensity flashing
white obstruction lights may be used during daytime
and twilight with automatically selected reduced
intensity for nighttime operation. When this system
is used on structures 500 feet (153m) AGL or less in
height, other methods of marking and lighting the
structure may be omitted. Aviation orange and white
paint is always required for daytime marking on
structures exceeding 500 feet (153m) AGL. This
system is not normally installed on structures less
than 200 feet (61m) AGL.
3. High Intensity White Obstruction Lights.
Flashing high intensity white lights during daytime
with reduced intensity for twilight and nighttime
operation. When this type system is used, the marking
of structures with red obstruction lights and aviation
orange and white paint may be omitted.
4. Dual Lighting. A combination of flashing
aviation red beacons and steady burning aviation red
lights for nighttime operation and flashing high
intensity white lights for daytime operation. Aviation
orange and white paint may be omitted.
5. Catenary Lighting. Lighted markers are
available for increased night conspicuity of highvoltage (69KV or higher) transmission line catenary
wires. Lighted markers provide conspicuity both day
and night.
b. Medium intensity omnidirectional flashing
white lighting system provides conspicuity both day
and night on catenary support structures. The unique
sequential/simultaneous flashing light system alerts
pilots of the associated catenary wires.
c. High intensity flashing white lights are being
used to identify some supporting structures of
overhead transmission lines located across rivers,
chasms, gorges, etc. These lights flash in a middle,
top, lower light sequence at approximately 60 flashes
per minute. The top light is normally installed near
the top of the supporting structure, while the lower
light indicates the approximate lower portion of the
AIM 2/14/08
2-2-2 Air Navigation and Obstruction Lighting
wire span. The lights are beamed towards the
companion structure and identify the area of the wire
span.
d. High intensity flashing white lights are also
employed to identify tall structures, such as chimneys
and towers, as obstructions to air navigation. The
lights provide a 360 degree coverage about the
structure at 40 flashes per minute and consist of from
one to seven levels of lights depending upon the
height of the structure. Where more than one level is
used the vertical banks flash simultaneously.
AIM 2/14/08
2-3-1
Airport Marking Aids and Signs
Section 3. Airport Marking Aids and Signs
2-3-1. General
a. Airport pavement markings and signs provide
information that is useful to a pilot during takeoff,
landing, and taxiing.
b. Uniformity in airport markings and signs from
one airport to another enhances safety and improves
efficiency. Pilots are encouraged to work with the
operators of the airports they use to achieve the
marking and sign standards described in this section.
c. Pilots who encounter ineffective, incorrect, or
confusing markings or signs on an airport should
make the operator of the airport aware of the problem.
These situations may also be reported under the
Aviation Safety Reporting Program as described in
paragraph_7-6-1, Aviation Safety Reporting Pro-
gram. Pilots may also report these situations to the
FAA regional airports division.
d. The markings and signs described in this
section of the AIM reflect the current FAA
recommended standards.
REFERENCE-
AC 150/5340-1, Standards for Airport Markings.
AC 150/5340-18, Standards for Airport Sign Systems.
2-3-2. Airport Pavement Markings
a. General. For the purpose of this presentation
the Airport Pavement Markings have been grouped
into four areas:
1. Runway Markings.
2. Taxiway Markings.
3. Holding Position Markings.
4. Other Markings.
b. Marking Colors. Markings for runways are
white. Markings defining the landing area on a
heliport are also white except for hospital heliports
which use a red “H” on a white cross. Markings for
taxiways, areas not intended for use by aircraft
(closed and hazardous areas), and holding positions
(even if they are on a runway) are yellow.
2-3-3. Runway Markings
a. General. There are three types of markings for
runways: visual, nonprecision instrument, and
precision instrument. TBL 2-3-1 identifies the
marking elements for each type of runway and
TBL 2-3-2 identifies runway threshold markings.
TBL 2-3-1
Runway Marking Elements
Marking Element Visual Runway
Nonprecision
Instrument
Runway
Precision
Instrument
Runway
Designation X X X
Centerline X X X
Threshold X1 X X
Aiming Point X2 X X
Touchdown Zone X
Side Stripes X
_1 On runways used, or intended to be used, by international commercial transports.
_2 On runways 4,000 feet (1200 m) or longer used by jet aircraft.
AIM 2/14/08
2-3-2 Airport Marking Aids and Signs
FIG 2-3-1
Precision Instrument Runway Markings
THRESHOLD MARKINGS
CONFIGURATION 'B'
NUMBER OF STRIPES
RELATED TO RUNWAY
WIDTH - SEE TEXT
20
L
AIMING POINT
MARKING
CENTERLINE
TOUCHDOWN ZONE
MARKING
THRESHOLD
THRESHOLD MARKINGS
CONFIGURATION 'A'
DESIGNATION MARKINGS
b. Runway Designators. Runway numbers and
letters are determined from the approach direction.
The runway number is the whole number nearest
one-tenth the magnetic azimuth of the centerline of
the runway, measured clockwise from the magnetic
north. The letters, differentiate between left (L),
right_(R), or center (C), parallel runways, as
applicable:
1. For two parallel runways “L” “R.”
2. For three parallel runways “L” “C” “R.”
c. Runway Centerline Marking. The runway
centerline identifies the center of the runway and
provides alignment guidance during takeoff and
landings. The centerline consists of a line of
uniformly spaced stripes and gaps.
d. Runway Aiming Point Marking. The aiming
point marking serves as a visual aiming point for a
landing aircraft. These two rectangular markings
consist of a broad white stripe located on each side of
the runway centerline and approximately 1,000 feet
from the landing threshold, as shown in FIG 2-3-1,
Precision Instrument Runway Markings.
e. Runway Touchdown Zone Markers. The
touchdown zone markings identify the touchdown
zone for landing operations and are coded to provide
distance information in 500 feet (150m) increments.
These markings consist of groups of one, two, and
three rectangular bars symmetrically arranged in
pairs about the runway centerline, as shown in
FIG 2-3-1, Precision Instrument Runway Markings.
For runways having touchdown zone markings on
both ends, those pairs of markings which extend to
within 900 feet (270m) of the midpoint between the
thresholds are eliminated.
AIM 2/14/08
2-3-3
Airport Marking Aids and Signs
FIG 2-3-2
Nonprecision Instrument Runway and Visual Runway Markings
20
20
AIMING POINT
MARKING
THRESHOLD THRESHOLD
MARKINGS
DESIGNATION
MARKING
PAVEMENT EDGE
AIMING POINT
MARKING
PAVEMENT EDGE
DESIGNATION MARKING
THRESHOLD
NONPRECISION INSTRUMENT RUNWAY MARKINGS
VISUAL RUNWAY MARKINGS
f. Runway Side Stripe Marking. Runway side
stripes delineate the edges of the runway. They
provide a visual contrast between runway and the
abutting terrain or shoulders. Side stripes consist of
continuous white stripes located on each side of the
runway as shown in FIG 2-3-4.
g. Runway Shoulder Markings. Runway shoul-
der stripes may be used to supplement runway side
stripes to identify pavement areas contiguous to the
runway sides that are not intended for use by aircraft.
Runway Shoulder stripes are Yellow.
(See FIG 2-3-5.)
h. Runway Threshold Markings. Runway
threshold markings come in two configurations. They
either consist of eight longitudinal stripes of uniform
dimensions disposed symmetrically about the
runway centerline, as shown in FIG 2-3-1, or the
number of stripes is related to the runway width as
indicated in TBL 2-3-2. A threshold marking helps
identify the beginning of the runway that is available
for landing. In some instances the landing threshold
may be relocated or displaced.
TBL 2-3-2
Number of Runway Threshold Stripes
Runway Width Number of Stripes
60 feet (18 m) 4
75 feet (23 m) 6
100 feet (30 m) 8
150 feet (45 m) 12
200 feet (60 m) 16
AIM 2/14/08
2-3-4 Airport Marking Aids and Signs
1. Relocation of a Threshold. Sometimes
construction, maintenance, or other activities require
the threshold to be relocated towards the rollout end
of the runway. (See FIG 2-3-3.) When a threshold is
relocated, it closes not only a set portion of the
approach end of a runway, but also shortens the length
of the opposite direction runway. In these cases, a
NOTAM should be issued by the airport operator
identifying the portion of the runway that is closed,
e.g., 10/28 W 900 CLSD. Because the duration of the
relocation can vary from a few hours to several
months, methods identifying the new threshold may
vary. One common practice is to use a ten feet wide
white threshold bar across the width of the runway.
Although the runway lights in the area between the
old threshold and new threshold will not be
illuminated, the runway markings in this area may or
may not be obliterated, removed, or covered.
2. Displaced Threshold. A displaced thresh-
old is a threshold located at a point on the runway
other than the designated beginning of the runway.
Displacement of a threshold reduces the length of
runway available for landings. The portion of runway
behind a displaced threshold is available for takeoffs
in either direction and landings from the opposite
direction. A ten feet wide white threshold bar is
located across the width of the runway at the
displaced threshold. White arrows are located along
the centerline in the area between the beginning of the
runway and displaced threshold. White arrow heads
are located across the width of the runway just prior
to the threshold bar, as shown in FIG 2-3-4.
NOTE-
Airport operator. When reporting the relocation or
displacement of a threshold, the airport operator should
avoid language which confuses the two.
i. Demarcation Bar. A demarcation bar delin-
eates a runway with a displaced threshold from a blast
pad, stopway or taxiway that precedes the runway. A
demarcation bar is 3 feet (1m) wide and yellow, since
it is not located on the runway as shown in
FIG 2-3-6.
1. Chevrons. These markings are used to show
pavement areas aligned with the runway that are
unusable for landing, takeoff, and taxiing. Chevrons
are yellow. (See FIG 2-3-7.)
j. Runway Threshold Bar. A threshold bar
delineates the beginning of the runway that is
available for landing when the threshold has been
relocated or displaced. A threshold bar is 10 feet (3m)
in width and extends across the width of the runway,
as shown in FIG 2-3-4.
AIM 2/14/08
2-3-5
Airport Marking Aids and Signs
FIG 2-3-3
Relocation of a Threshold with Markings for Taxiway Aligned with Runway
AIM 2/14/08
2-3-6 Airport Marking Aids and Signs
FIG 2-3-4
Displaced Threshold Markings
AIM 2/14/08
2-3-7
Airport Marking Aids and Signs
FIG 2-3-5
Runway Shoulder Markings
RUNWAY THRESHOLD
MIDPOINT OF
RUNWAY
SHOULDER SHOULDER
RUNWAY
45
45
45
45
2-3-4. Taxiway Markings
a. General. All taxiways should have centerline
markings and runway holding position markings
whenever they intersect a runway. Taxiway edge
markings are present whenever there is a need to
separate the taxiway from a pavement that is not
intended for aircraft use or to delineate the edge of the
taxiway. Taxiways may also have shoulder markings
and holding position markings for Instrument
Landing System/Microwave Landing System (ILS/
MLS) critical areas, and taxiway/taxiway
intersection markings.
REFERENCE-
AIM, Holding Position Markings, Paragraph 2-3-5.
b. Taxiway Centerline.
1. Normal Centerline. The taxiway centerline
is a single continuous yellow line, 6 inches (15 cm) to
12 inches (30 cm) in width. This provides a visual cue
to permit taxiing along a designated path. Ideally, the
aircraft should be kept centered over this line during
taxi. However, being centered on the taxiway
centerline does not guarantee wingtip clearance with
other aircraft or other objects.
2. Enhanced Centerline. At some airports,
mostly the larger commercial service airports, an
enhanced taxiway centerline will be used. The
enhanced taxiway centerline marking consists of a
parallel line of yellow dashes on either side of the
normal taxiway centerline. The taxiway centerlines
are enhanced for a maximum of 150 feet prior to a
runway holding position marking. The purpose of
this enhancement is to warn the pilot that he/she is
approaching a runway holding position marking and
should prepare to stop unless he/she has been cleared
onto or across the runway by ATC. (See FIG 2-3-8.)
c. Taxiway Edge Markings. Taxiway edge
markings are used to define the edge of the taxiway.
They are primarily used when the taxiway edge does
not correspond with the edge of the pavement. There
are two types of markings depending upon whether
the aircraft is suppose to cross the taxiway edge:
1. Continuous Markings. These consist of a
continuous double yellow line, with each line being
at least 6 inches (15 cm) in width spaced 6 inches
(15_cm) apart. They are used to define the taxiway
edge from the shoulder or some other abutting paved
surface not intended for use by aircraft.
2. Dashed Markings. These markings are
used when there is an operational need to define the
edge of a taxiway or taxilane on a paved surface
where the adjoining pavement to the taxiway edge is
intended for use by aircraft, e.g., an apron. Dashed
taxiway edge markings consist of a broken double
yellow line, with each line being at least 6 inches
(15_cm) in width, spaced 6 inches (15 cm) apart (edge
to edge). These lines are 15 feet (4.5 m) in length with
25 foot (7.5 m) gaps. (See FIG 2-3-9.)
d. Taxi Shoulder Markings. Taxiways, holding
bays, and aprons are sometimes provided with paved
shoulders to prevent blast and water erosion.
Although shoulders may have the appearance of full
strength pavement they are not intended for use by
aircraft, and may be unable to support an aircraft.
Usually the taxiway edge marking will define this
area. Where conditions exist such as islands or
taxiway curves that may cause confusion as to which
side of the edge stripe is for use by aircraft, taxiway
shoulder markings may be used to indicate the
pavement is unusable. Taxiway shoulder markings
are yellow. (See FIG 2-3-10.)
AIM 2/14/08
2-3-8 Airport Marking Aids and Signs
FIG 2-3-6
Markings for Blast Pad or Stopway or Taxiway Preceding a Displaced Threshold
AIM 2/14/08
2-3-9
Airport Marking Aids and Signs
FIG 2-3-7
Markings for Blast Pads and Stopways
AIM 2/14/08
2-3-10 Airport Marking Aids and Signs
FIG 2-3-8
Enhanced Taxiway Centerline
FIG 2-3-9
Dashed Markings
DOUBLE
YELLOW
LINES
TAXIWAY EDGE
MARKINGS
CONTINUOUS
TAXIWAY EDGE
MARKINGS
DASHED
e. Surface Painted Taxiway Direction
Signs. Surface painted taxiway direction signs have
a yellow background with a black inscription, and are
provided when it is not possible to provide taxiway
direction signs at intersections, or when necessary to
supplement such signs. These markings are located
adjacent to the centerline with signs indicating turns
to the left being on the left side of the taxiway
centerline and signs indicating turns to the right being
on the right side of the centerline. (See FIG 2-3-11.)
FIG 2-3-10
Taxi Shoulder Markings
YELLOW STRIPES
PAVEMENT EDGE
TAXIWAY EDGE
MARKINGS
RUNWAY
f. Surface Painted Location Signs. Surface
painted location signs have a black background with
a yellow inscription. When necessary, these markings
are used to supplement location signs located along
side the taxiway and assist the pilot in confirming the
designation of the taxiway on which the aircraft is
located. These markings are located on the right side
of the centerline. (See FIG 2-3-11.)
g. Geographic Position Markings. These mark-
ings are located at points along low visibility taxi
routes designated in the airport's Surface Movement
Guidance Control System (SMGCS) plan. They are
used to identify the location of taxiing aircraft during
low visibility operations. Low visibility operations
are those that occur when the runway visible
range_(RVR) is below 1200 feet(360m). They are
positioned to the left of the taxiway centerline in the
direction of taxiing. (See FIG 2-3-12.) The
geographic position marking is a circle comprised of
an outer black ring contiguous to a white ring with a
pink circle in the middle. When installed on asphalt
or other dark-colored pavements, the white ring and
the black ring are reversed, i.e., the white ring
becomes the outer ring and the black ring becomes the
inner ring. It is designated with either a number or a
number and letter. The number corresponds to the
consecutive position of the marking on the route.
AIM 2/14/08
2-3-11
Airport Marking Aids and Signs
FIG 2-3-11
Surface Painted Signs
AIM 2/14/08
2-3-12 Airport Marking Aids and Signs
2-3-5. Holding Position Markings
a. Runway Holding Position Markings. For
runways, these markings indicate where an aircraft is
supposed to stop when approaching a runway. They
consist of four yellow lines, two solid and two dashed,
spaced six or twelve inches apart, and extending
across the width of the taxiway or runway. The solid
lines are always on the side where the aircraft is to
hold. There are three locations where runway holding
position markings are encountered.
1. Runway Holding Position Markings on
Taxiways. These markings identify the locations on
a taxiway where an aircraft is supposed to stop when
it does not have clearance to proceed onto the runway.
Generally, runway holding position markings also
identify the boundary of the runway safety area for
aircraft exiting the runway. The runway holding
position markings are shown in FIG 2-3-13 and
FIG 2-3-16. When instructed by ATC to, “Hold short
of (runway “xx”),” the pilot must stop so that no part
of the aircraft extends beyond the runway holding
position marking. When approaching the runway, a
pilot should not cross the runway holding position
marking without ATC clearance at a controlled
airport, or without making sure of adequate
separation from other aircraft at uncontrolled
airports. An aircraft exiting a runway is not clear of
the runway until all parts of the aircraft have crossed
the applicable holding position marking.
REFERENCE-
AIM, Exiting the Runway After Landing,. Paragraph 4-3-20.
2. Runway Holding Position Markings on
Runways. These markings are installed on runways
only if the runway is normally used by air traffic
control for “land, hold short” operations or taxiing
operations and have operational significance only for
those two types of operations. A sign with a white
inscription on a red background is installed adjacent
to these holding position markings. (See
FIG 2-3-14.) The holding position markings are
placed on runways prior to the intersection with
another runway, or some designated point. Pilots
receiving instructions “cleared to land, runway “xx””
from air traffic control are authorized to use the entire
landing length of the runway and should disregard
any holding position markings located on the runway.
Pilots receiving and accepting instructions “cleared
to land runway “xx,” hold short of runway “yy”” from
air traffic control must either exit runway “xx,” or
stop at the holding position prior to runway “yy.”
3. Taxiways Located in Runway Approach
Areas. These markings are used at some airports
where it is necessary to hold an aircraft on a taxiway
located in the approach or departure area of a runway
so that the aircraft does not interfere with the
operations on that runway. This marking is collocated
with the runway approach area holding position sign.
When specifically instructed by ATC “Hold short of
(runway xx approach area)” the pilot should stop so
no part of the aircraft extends beyond the holding
position marking. (See subparagraph_2-3-8b2,
Runway Approach Area Holding Position Sign, and
FIG 2-3-15.)
b. Holding Position Markings for Instrument
Landing System (ILS). Holding position markings
for ILS/MLS critical areas consist of two yellow solid
lines spaced two feet apart connected by pairs of solid
lines spaced ten feet apart extending across the width
of the taxiway as shown. (See FIG 2-3-16.) A sign
with an inscription in white on a red background is
installed adjacent to these hold position markings.
When the ILS critical area is being protected, the pilot
should stop so no part of the aircraft extends beyond
the holding position marking. When approaching the
holding position marking, a pilot should not cross the
marking without ATC clearance. ILS critical area is
not clear until all parts of the aircraft have crossed the
applicable holding position marking.
REFERENCE-
AIM, Instrument Landing System (ILS), Paragraph 1-1-9.
c. Holding Position Markings for Taxiway/
Taxiway Intersections. Holding position markings
for taxiway/taxiway intersections consist of a single
dashed line extending across the width of the taxiway
as shown. (See FIG 2-3-17.) They are installed on
taxiways where air traffic control normally holds
aircraft short of a taxiway intersection. When
instructed by ATC “hold short of (taxiway)” the pilot
should stop so no part of the aircraft extends beyond
the holding position marking. When the marking is
not present the pilot should stop the aircraft at a point
which provides adequate clearance from an aircraft
on the intersecting taxiway.
d. Surface Painted Holding Position Signs.
Surface painted holding position signs have a red
background with a white inscription and supplement
the signs located at the holding position. This type of
marking is normally used where the width of the
holding position on the taxiway is greater than 200
feet(60m). It is located to the left side of the taxiway
centerline on the holding side and prior to the holding
position marking. (See FIG 2-3-11.)
AIM 2/14/08
2-3-13
Airport Marking Aids and Signs
FIG 2-3-12
Geographic Position Markings
FIG 2-3-13
Runway Holding Position Markings on Taxiway
RUNWAY
TAXIWAY
EXAMPLE OF HOLDING POSITION MARKINGS
EXTENDED ACROSS HOLDING BAY
HOLDING
BAY
15
TAXIWAY/RUNWAY
HOLDING POSITION
MARKINGS
AIM 2/14/08
2-3-14 Airport Marking Aids and Signs
FIG 2-3-14
Runway Holding Position Markings on Runways
AIM 2/14/08
2-3-15
Airport Marking Aids and Signs
FIG 2-3-15
Taxiways Located in Runway Approach Area
AIM 2/14/08
2-3-16 Airport Marking Aids and Signs
FIG 2-3-16
Holding Position Markings: ILS Critical Area
15
DETAIL 2
DETAIL 1
RUNWAY HOLDING
POSITION MARKINGS,
YELLOW, SEE
DETAIL 1
ILS HOLDING
POSITION MARKINGS,
YELLOW, SEE
DETAIL 2
ILS CRITICAL
AREA
2-3-6. Other Markings
a. Vehicle Roadway Markings. The vehicle
roadway markings are used when necessary to define
a pathway for vehicle operations on or crossing areas
that are also intended for aircraft. These markings
consist of a white solid line to delineate each edge of
the roadway and a dashed line to separate lanes within
the edges of the roadway. In lieu of the solid lines,
zipper markings may be used to delineate the edges
of the vehicle roadway. (See FIG 2-3-18.) Details of
the zipper markings are shown in FIG 2-3-19.
b. VOR Receiver Checkpoint Markings. The
VOR receiver checkpoint marking allows the pilot to
check aircraft instruments with navigational aid
signals. It consists of a painted circle with an arrow in
the middle; the arrow is aligned in the direction of the
checkpoint azimuth. This marking, and an associated
sign, is located on the airport apron or taxiway at a
point selected for easy access by aircraft but where
other airport traffic is not to be unduly obstructed.
(See FIG 2-3-20.)
NOTE-
The associated sign contains the VOR station identification
letter and course selected (published) for the check, the
words “VOR check course,” and DME data (when
applicable). The color of the letters and numerals are black
on a yellow background.
EXAMPLE-
DCA 176-356
VOR check course
DME XXX
AIM 2/14/08
2-3-17
Airport Marking Aids and Signs
FIG 2-3-17
Holding Position Markings: Taxiway/Taxiway Intersections
TAXIWAY HOLDING
POSITION MARKINGS,
YELLOW, SEE
DETAIL 1
DETAIL 1
FIG 2-3-18
Vehicle Roadway Markings
AIM 2/14/08
2-3-18 Airport Marking Aids and Signs
FIG 2-3-19
Roadway Edge Stripes, White, Zipper Style
c. Nonmovement Area Boundary Markings.
These markings delineate the movement area,
i.e.,_area under air traffic control. These markings are
yellow and located on the boundary between the
movement and nonmovement area. The nonmove-
ment area boundary markings consist of two yellow
lines (one solid and one dashed) 6 inches (15cm) in
width. The solid line is located on the nonmovement
area side while the dashed yellow line is located on
the movement area side. The nonmovement
boundary marking area is shown in FIG 2-3-21.
FIG 2-3-20
Ground Receiver Checkpoint Markings
1
4
2
3
1. WHITE
2. YELLOW
3. YELLOW ARROW ALIGNED TOWARD THE FACILITY
4. INTERIOR OF CIRCLE BLACK (CONCRETE SURFACE ONLY)
5. CIRCLE MAY BE BORDERED ON INSIDE AND OUTSIDE WITH
6” BLACK BAND IF NECESSARY FOR CONTRAST
5
FIG 2-3-21
Nonmovement Area Boundary Markings
BOTH LINES
ARE YELLOW
SOLID LINE ON
NONMOVEMENT
SIDE
DASHED LINE ON
MOVEMENT SIDE
FIG 2-3-22
Closed or Temporarily Closed Runway
and Taxiway Markings
2
X
d. Marking and Lighting of Permanently
Closed Runways and Taxiways. For runways and
taxiways which are permanently closed, the lighting
circuits will be disconnected. The runway threshold,
runway designation, and touchdown markings are
obliterated and yellow crosses are placed at each end
of the runway and at 1,000 foot intervals.
(See FIG 2-3-22.)
AIM 2/14/08
2-3-19
Airport Marking Aids and Signs
FIG 2-3-23
Helicopter Landing Areas
e. Temporarily Closed Runways and Taxiways.
To provide a visual indication to pilots that a runway
is temporarily closed, crosses are placed on the
runway only at each end of the runway. The crosses
are yellow in color. (See FIG 2-3-22.)
1. A raised lighted yellow cross may be placed
on each runway end in lieu of the markings described
in subparagraph e,Temporarily Closed Runways and
Taxiways, to indicate the runway is closed.
2. A visual indication may not be present
depending on the reason for the closure, duration of
the closure, airfield configuration and the existence
and the hours of operation of an airport traffic control
tower. Pilots should check NOTAMs and the
Automated Terminal Information System (ATIS) for
local runway and taxiway closure information.
3. Temporarily closed taxiways are usually
treated as hazardous areas, in which no part of an
aircraft may enter, and are blocked with barricades.
However, as an alternative a yellow cross may be
installed at each entrance to the taxiway.
f. Helicopter Landing Areas. The markings
illustrated in FIG 2-3-23 are used to identify the
landing and takeoff area at a public use heliport and
hospital heliport. The letter “H” in the markings is
oriented to align with the intended direction of
approach. FIG 2-3-23 also depicts the markings for
a closed airport.
2-3-7. Airport Signs
There are six types of signs installed on airfields:
mandatory instruction signs, location signs, direction
signs, destination signs, information signs, and
runway distance remaining signs. The characteristics
and use of these signs are discussed in para-
graph_2-3-8, Mandatory Instruction Signs, through
paragraph 2-3-13, Runway Distance Remaining
Signs.
REFERENCE-
AC150/5340-18, Standards for Airport Sign Systems for Detailed
Information on Airport Signs.
AIM 2/14/08
2-3-20 Airport Marking Aids and Signs
FIG 2-3-24
Runway Holding Position Sign
FIG 2-3-25
Holding Position Sign at Beginning of Takeoff Runway
2-3-8. Mandatory Instruction Signs
a. These signs have a red background with a white
inscription and are used to denote:
1. An entrance to a runway or critical area and;
2. Areas where an aircraft is prohibited from
entering.
b. Typical mandatory signs and applications
are:
1. Runway Holding Position Sign. This sign
is located at the holding position on taxiways that
intersect a runway or on runways that intersect other
runways. The inscription on the sign contains the
designation of the intersecting runway as shown in
FIG 2-3-24. The runway numbers on the sign are
arranged to correspond to the respective runway
threshold. For example, “15-33” indicates that the
threshold for Runway 15 is to the left and the
threshold for Runway 33 is to the right.
(a) On taxiways that intersect the beginning
of the takeoff runway, only the designation of the
takeoff runway may appear on the sign as shown in
FIG 2-3-25, while all other signs will have the
designation of both runway directions.
AIM 2/14/08
2-3-21
Airport Marking Aids and Signs
FIG 2-3-26
Holding Position Sign for a Taxiway that Intersects the Intersection of Two Runways
FIG 2-3-27
Holding Position Sign for a Runway Approach Area
(b) If the sign is located on a taxiway that
intersects the intersection of two runways, the
designations for both runways will be shown on the
sign along with arrows showing the approximate
alignment of each runway as shown in FIG 2-3-26.
In addition to showing the approximate runway
alignment, the arrow indicates the direction to the
threshold of the runway whose designation is
immediately next to the arrow.
(c) A runway holding position sign on a
taxiway will be installed adjacent to holding position
markings on the taxiway pavement. On runways,
holding position markings will be located only on the
runway pavement adjacent to the sign, if the runway
is normally used by air traffic control for “Land, Hold
Short” operations or as a taxiway. The holding
position markings are described in paragraph 2-3-5,
Holding Position Markings.
2. Runway Approach Area Holding Position
Sign. At some airports, it is necessary to hold an
aircraft on a taxiway located in the approach or
departure area for a runway so that the aircraft does
not interfere with operations on that runway. In these
situations, a sign with the designation of the approach
end of the runway followed by a “dash” (-) and letters
“APCH” will be located at the holding position on the
taxiway. Holding position markings in accordance
with paragraph 2-3-5, Holding Position Markings,
will be located on the taxiway pavement. An example
of this sign is shown in FIG 2-3-27. In this example,
the sign may protect the approach to Runway 15
and/or the departure for Runway 33.
AIM 2/14/08
2-3-22 Airport Marking Aids and Signs
FIG 2-3-28
Holding Position Sign for ILS Critical Area
FIG 2-3-29
Sign Prohibiting Aircraft Entry into an Area
3. ILS Critical Area Holding Position
Sign. At some airports, when the instrument landing
system is being used, it is necessary to hold an aircraft
on a taxiway at a location other than the holding
position described in paragraph 2-3-5, Holding
Position Markings. In these situations the holding
position sign for these operations will have the
inscription “ILS” and be located adjacent to the
holding position marking on the taxiway described in
paragraph 2-3-5. An example of this sign is shown
in FIG 2-3-28.
4. No Entry Sign. This sign, shown in
FIG 2-3-29, prohibits an aircraft from entering an
area. Typically, this sign would be located on a
taxiway intended to be used in only one direction or
at the intersection of vehicle roadways with runways,
taxiways or aprons where the roadway may be
mistaken as a taxiway or other aircraft movement
surface.
NOTE-
The holding position sign provides the pilot with a visual
cue as to the location of the holding position marking. The
operational significance of holding position markings are
described in the notes for paragraph 2-3-5, Holding
Position Markings.
AIM 2/14/08
2-3-23
Airport Marking Aids and Signs
FIG 2-3-30
Taxiway Location Sign
FIG 2-3-31
Taxiway Location Sign Collocated with Runway Holding Position Sign
2-3-9. Location Signs
a. Location signs are used to identify either a
taxiway or runway on which the aircraft is located.
Other location signs provide a visual cue to pilots to
assist them in determining when they have exited an
area. The various location signs are described below.
1. Taxiway Location Sign. This sign has a
black background with a yellow inscription and
yellow border as shown in FIG 2-3-30. The
inscription is the designation of the taxiway on which
the aircraft is located. These signs are installed along
taxiways either by themselves or in conjunction with
direction signs or runway holding position signs.
(See FIG 2-3-35 and FIG 2-3-31.)
AIM 2/14/08
2-3-24 Airport Marking Aids and Signs
FIG 2-3-32
Runway Location Sign
FIG 2-3-33
Runway Boundary Sign
2. Runway Location Sign. This sign has a
black background with a yellow inscription and
yellow border as shown in FIG 2-3-32. The
inscription is the designation of the runway on which
the aircraft is located. These signs are intended to
complement the information available to pilots
through their magnetic compass and typically are
installed where the proximity of two or more runways
to one another could cause pilots to be confused as to
which runway they are on.
3. Runway Boundary Sign. This sign has a
yellow background with a black inscription with a
graphic depicting the pavement holding position
marking as shown in FIG 2-3-33. This sign, which
faces the runway and is visible to the pilot exiting the
runway, is located adjacent to the holding position
marking on the pavement. The sign is intended to
provide pilots with another visual cue which they can
use as a guide in deciding when they are “clear of the
runway.”
AIM 2/14/08
2-3-25
Airport Marking Aids and Signs
FIG 2-3-34
ILS Critical Area Boundary Sign
4. ILS Critical Area Boundary Sign. This
sign has a yellow background with a black inscription
with a graphic depicting the ILS pavement holding
position marking as shown in FIG 2-3-34. This sign
is located adjacent to the ILS holding position
marking on the pavement and can be seen by pilots
leaving the critical area. The sign is intended to
provide pilots with another visual cue which they can
use as a guide in deciding when they are “clear of the
ILS critical area.”
2-3-10. Direction Signs
a. Direction signs have a yellow background with
a black inscription. The inscription identifies the
designation(s) of the intersecting taxiway(s) leading
out of the intersection that a pilot would normally be
expected to turn onto or hold short of. Each
designation is accompanied by an arrow indicating
the direction of the turn.
b. Except as noted in subparagraph e, each
taxiway designation shown on the sign is accompanied by only one arrow. When more than one taxiway
designation is shown on the sign each designation and
its associated arrow is separated from the other
taxiway designations by either a vertical message
divider or a taxiway location sign as shown in
FIG 2-3-35.
c. Direction signs are normally located on the left
prior to the intersection. When used on a runway to
indicate an exit, the sign is located on the same side
of the runway as the exit. FIG 2-3-36 shows a
direction sign used to indicate a runway exit.
d. The taxiway designations and their associated
arrows on the sign are arranged clockwise starting
from the first taxiway on the pilot's left.
(See FIG 2-3-35.)
e. If a location sign is located with the direction
signs, it is placed so that the designations for all turns
to the left will be to the left of the location sign; the
designations for continuing straight ahead or for all
turns to the right would be located to the right of the
location sign. (See FIG 2-3-35.)
f. When the intersection is comprised of only one
crossing taxiway, it is permissible to have two arrows
associated with the crossing taxiway as shown in
FIG 2-3-37. In this case, the location sign is located
to the left of the direction sign.
AIM 2/14/2-3-26 Airport Marking Aids and Signs
FIG 2-3-35
Direction Sign Array with Location Sign on Far Side of Intersection
FIG 2-3-36
Direction Sign for Runway Exit
3/15/07 7110.65R CHG 2 AIM 7/31/08
AIM 2/14/08
2-3-27
Airport Marking Aids and Signs
FIG 2-3-37
Direction Sign Array for Simple Intersection
AIM 2/14/08
2-3-28 Airport Marking Aids and Signs
FIG 2-3-38
Destination Sign for Military Area
FIG 2-3-39
Destination Sign for Common Taxiing Route to Two Runways
2-3-11. Destination Signs
a. Destination signs also have a yellow back-
ground with a black inscription indicating a
destination on the airport. These signs always have an
arrow showing the direction of the taxiing route to
that destination. FIG 2-3-38 is an example of a
typical destination sign. When the arrow on the
destination sign indicates a turn, the sign is located
prior to the intersection.
b. Destinations commonly shown on these types
of signs include runways, aprons, terminals, military
areas, civil aviation areas, cargo areas, international
areas, and fixed base operators. An abbreviation may
be used as the inscription on the sign for some of these
destinations.
c. When the inscription for two or more
destinations having a common taxiing route are
placed on a sign, the destinations are separated by a
“dot” (_) and one arrow would be used as shown in
FIG 2-3-39. When the inscription on a sign contains
two or more destinations having different taxiing
routes, each destination will be accompanied by an
arrow and will be separated from the other
destinations on the sign with a vertical black message
divider as shown in FIG 2-3-40.
AIM 2/14/08
2-3-29
Airport Marking Aids and Signs
FIG 2-3-40
Destination Sign for Different Taxiing Routes to Two Runways
2-3-12. Information Signs
Information signs have a yellow background with a
black inscription. They are used to provide the pilot
with information on such things as areas that cannot
be seen from the control tower, applicable radio
frequencies, and noise abatement procedures. The
airport operator determines the need, size, and
location for these signs.
2-3-13. Runway Distance Remaining Signs
Runway distance remaining signs have a black
background with a white numeral inscription and
may be installed along one or both side(s) of the
runway. The number on the signs indicates the
distance (in thousands of feet) of landing runway
remaining. The last sign, i.e., the sign with the
numeral “1,” will be located at least 950 feet from the
runway end. FIG 2-3-41 shows an example of a
runway distance remaining sign.
FIG 2-3-41
Runway Distance Remaining Sign Indicating
3,000 feet of Runway Remaining
3
AIM 2/14/2-3-30 Airport Marking Aids and Signs
2-3-14. Aircraft Arresting Systems
a. Certain airports are equipped with a means of
rapidly stopping military aircraft on a runway. This
equipment, normally referred to as EMERGENCY
ARRESTING GEAR, generally consists of pendant
cables supported over the runway surface by rubber
“donuts.” Although most devices are located in the
overrun areas, a few of these arresting systems have
cables stretched over the operational areas near the
ends of a runway.
b. Arresting cables which cross over a runway
require special markings on the runway to identify
the cable location. These markings consist of 10 feet
diameter solid circles painted “identification yellow,” 30 feet on center, perpendicular to the runway
centerline across the entire runway width. Additional
details are contained in AC 150/5220-9, Aircraft
Arresting Systems for Joint Civil/Military Airports.
NOTE-
Aircraft operations on the runway are not restricted by the
installation of aircraft arresting devices.
c. Engineered materials arresting systems
(EMAS). EMAS, which are constructed of high
energy-absorbing materials of selected strength, are
located in the safety area beyond the end of the
runway. They are designed to crush under the weight
of commercial aircraft and they exert deceleration
forces on the landing gear. These systems do not
affect the normal landing and takeoff of airplanes.
More information concerning EMAS is in FAA
Advisory Circular AC 150/5220-22, Engineered
Materials Arresting Systems (EMAS) for Aircraft
Overruns.
NOTE-
EMAS may be located as close as 35 feet beyond the end of
the runway. Aircraft should never taxi or drive across the
runway.
FIG 2-3-42
Engineered Materials Arresting System (EMAS)
3/15/07 7110.65R CHG 2 AIM 7/31/08
AIM 2/14/08
3-1-1
General
Chapter 3. Airspace
Section 1. General
3-1-1. General
a. There are two categories of airspace or airspace
areas:
1. Regulatory (Class A, B, C, D and E airspace
areas, restricted and prohibited areas); and
2. Nonregulatory (military operations areas
(MOAs), warning areas, alert areas, and controlled
firing areas).
NOTE-
Additional information on special use airspace (prohibited
areas, restricted areas, warning areas, MOAs, alert areas
and controlled firing areas) may be found in Chapter 3,
Airspace, Section 4, Special Use Airspace, para-
graphs_3-4-1 through 3-4-7.
b. Within these two categories, there are four
types:
1. Controlled,
2. Uncontrolled,
3. Special use, and
4. Other airspace.
c. The categories and types of airspace are dictated
by:
1. The complexity or density of aircraft
movements,
2. The nature of the operations conducted
within the airspace,
3. The level of safety required, and
4. The national and public interest.
d. It is important that pilots be familiar with the
operational requirements for each of the various types
or classes of airspace. Subsequent sections will cover
each class in sufficient detail to facilitate
understanding.
3-1-2. General Dimensions of Airspace
Segments
Refer to Code of Federal Regulations (CFRs) for
specific dimensions, exceptions, geographical areas
covered, exclusions, specific transponder or equip-
ment requirements, and flight operations.
3-1-3. Hierarchy of Overlapping Airspace
Designations
a. When overlapping airspace designations apply
to the same airspace, the operating rules associated
with the more restrictive airspace designation apply.
b. For the purpose of clarification:
1. Class A airspace is more restrictive than
Class_B, Class C, Class D, Class E, or Class G
airspace;
2. Class B airspace is more restrictive than
Class_C, Class D, Class E, or Class G airspace;
3. Class C airspace is more restrictive than
Class_D, Class E, or Class G airspace;
4. Class D airspace is more restrictive than
Class_E or Class G airspace; and
5. Class E is more restrictive than Class G
airspace.
3-1-4. Basic VFR Weather Minimums
a. No person may operate an aircraft under basic
VFR when the flight visibility is less, or at a distance
from clouds that is less, than that prescribed for the
corresponding altitude and class of airspace.
(See TBL 3-1-1.)
NOTE-
Student pilots must comply with 14 CFR Section 61.89(a)
(6) and (7).
b. Except as provided in 14 CFR Section 91.157,
Special VFR Weather Minimums, no person may
operate an aircraft beneath the ceiling under VFR
within the lateral boundaries of controlled airspace
designated to the surface for an airport when the
ceiling is less than 1,000 feet. (See 14 CFR
Section_91.155(c).)
AIM 2/14/08
3-1-2 General
TBL 3-1-1
Basic VFR Weather Minimums
Airspace Flight Visibility Distance from Clouds
Class A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Not Applicable Not Applicable
Class B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 statute miles Clear of Clouds
Class C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 statute miles 500 feet below
1,000 feet above
2,000 feet horizontal
Class D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 statute miles 500 feet below
1,000 feet above
2,000 feet horizontal
Class E
Less than 10,000 feet MSL . . . . . . . . . . . . . . . . . . . . . . . . 3 statute miles 500 feet below
1,000 feet above
2,000 feet horizontal
At or above 10,000 feet MSL . . . . . . . . . . . . . . . . . . . . . . 5 statute miles 1,000 feet below
1,000 feet above
1 statute mile horizontal
Class G
1,200 feet or less above the surface (regardless of MSL
altitude).
Day, except as provided in section 91.155(b) . . . . . . . . . . 1 statute mile Clear of clouds
Night, except as provided in section 91.155(b) . . . . . . . . . 3 statute miles 500 feet below
1,000 feet above
2,000 feet horizontal
More than 1,200 feet above the surface but less than
10,000 feet MSL.
Day . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 statute mile 500 feet below
1,000 feet above
2,000 feet horizontal
Night . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 statute miles 500 feet below
1,000 feet above
2,000 feet horizontal
More than 1,200 feet above the surface and at or above
10,000 feet MSL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 statute miles 1,000 feet below
1,000 feet above
1 statute mile horizontal
3-1-5. VFR Cruising Altitudes and Flight Levels
(See TBL 3-1-2.)
TBL 3-1-2
VFR Cruising Altitudes and Flight Levels
If your magnetic course
(ground track) is:
And you are more than 3,000 feet above the
surface but below 18,000 feet MSL, fly:
And you are above 18,000 feet
MSL to FL 290, fly:
0
_
to 179
_
. . . . . . . . . . . . . . . . Odd thousands MSL, plus 500 feet
(3,500; 5,500; 7,500, etc.)
Odd Flight Levels plus 500 feet
(FL 195; FL 215; FL 235, etc.)
180
_
to 359
_
. . . . . . . . . . . . . . Even thousands MSL, plus 500 feet
(4,500; 6,500; 8,500, etc.)
Even Flight Levels plus 500 feet
(FL 185; FL 205; FL 225, etc.)
AIM 2/14/08
3-2-1
Controlled Airspace
Section 2. Controlled Airspace
3-2-1. General
a. Controlled Airspace. A generic term that
covers the different classification of airspace
(Class_A, Class_B, Class C, Class D, and Class E
airspace) and defined dimensions within which air
traffic control service is provided to IFR flights and
to VFR flights in accordance with the airspace
classification. (See FIG 3-2-1.)
b. IFR Requirements. IFR operations in any
class of controlled airspace requires that a pilot must
file an IFR flight plan and receive an appropriate ATC
clearance.
c. IFR Separation. Standard IFR separation is
provided to all aircraft operating under IFR in
controlled airspace.
d. VFR Requirements. It is the responsibility of
the pilot to insure that ATC clearance or radio
communication requirements are met prior to entry
into Class B, Class C, or Class D airspace. The pilot
retains this responsibility when receiving ATC radar
advisories. (See 14 CFR Part 91.)
e. Traffic Advisories. Traffic advisories will be
provided to all aircraft as the controller's work
situation permits.
f. Safety Alerts. Safety Alerts are mandatory
services and are provided to ALL aircraft. There are
two types of Safety Alerts:
1. Terrain/Obstruction Alert. A Terrain/
Obstruction Alert is issued when, in the controller's
judgment, an aircraft's altitude places it in unsafe
proximity to terrain and/or obstructions; and
2. Aircraft Conflict/Mode C Intruder Alert.
An Aircraft Conflict/Mode C Intruder Alert is issued
if the controller observes another aircraft which
places it in an unsafe proximity. When feasible, the
controller will offer the pilot an alternative course of
action.
FIG 3-2-1
Airspace Classes
MSL - mean sea level
AGL - above ground level
FL - flight level
CLASS B
CLASS C
CLASS E
CLASS D
CLASS G CLASS G CLASS G
Nontowered
Airport
FL 600
18,000 MSL
14,500 MSL
1,200 AGL 700 AGL
CLASS A
AIM 2/14/08
3-2-2 Controlled Airspace
g. Ultralight Vehicles. No person may operate an
ultralight vehicle within Class A, Class B, Class C, or
Class D airspace or within the lateral boundaries of
the surface area of Class E airspace designated for an
airport unless that person has prior authorization from
the ATC facility having jurisdiction over that
airspace. (See 14 CFR Part 103.)
h. Unmanned Free Balloons. Unless otherwise
authorized by ATC, no person may operate an
unmanned free balloon below 2,000 feet above the
surface within the lateral boundaries of Class B,
Class_C, Class_D, or Class E airspace designated for
an airport. (See 14 CFR Part_101.)
i. Parachute Jumps. No person may make a
parachute jump, and no pilot-in-command may
allow a parachute jump to be made from that aircraft,
in or into Class A, Class B, Class C, or Class D
airspace without, or in violation of, the terms of an
ATC authorization issued by the ATC facility having
jurisdiction over the airspace. (See 14 CFR Part 105.)
3-2-2. Class A Airspace
a. Definition. Generally, that airspace from
18,000 feet MSL up to and including FL 600,
including the airspace overlying the waters within
12_nautical miles of the coast of the 48 contiguous
States and Alaska; and designated international
airspace beyond 12 nautical miles 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.
b. Operating Rules and Pilot/Equipment
Requirements. Unless otherwise authorized, all
persons must operate their aircraft under IFR. (See
14_CFR Section_71.33 and 14 CFR Section 91.167
through 14_CFR Section_91.193.)
c. Charts. Class A airspace is not specifically
charted.
3-2-3. Class B Airspace
a. Definition. Generally, that airspace from the
surface to 10,000 feet MSL surrounding the nation's
busiest airports in terms of IFR operations or
passenger enplanements. The configuration of each
Class B airspace area is individually tailored and
consists of a surface area and two or more layers
(some Class B airspace areas resemble upside-down
wedding cakes), and is designed to contain all
published instrument procedures once an aircraft
enters the airspace. An ATC clearance is required for
all aircraft to operate in the area, and all aircraft that
are so cleared receive separation services within the
airspace. The cloud clearance requirement for VFR
operations is “clear of clouds.”
b. Operating Rules and Pilot/Equipment
Requirements for VFR Operations. Regardless of
weather conditions, an ATC clearance is required
prior to operating within Class B airspace. Pilots
should not request a clearance to operate within
Class_B airspace unless the requirements of 14 CFR
Section 91.215 and 14 CFR Section 91.131 are met.
Included among these requirements are:
1. Unless otherwise authorized by ATC, aircraft
must be equipped with an operable two-way radio
capable of communicating with ATC on appropriate
frequencies for that Class B airspace.
2. No person may take off or land a civil aircraft
at the following primary airports within Class B
airspace unless the pilot-in-command holds at least
a private pilot certificate:
(a) Andrews Air Force Base, MD
(b) Atlanta Hartsfield Airport, GA
(c) Boston Logan Airport, MA
(d) Chicago O'Hare Intl. Airport, IL
(e) Dallas/Fort Worth Intl. Airport, TX
(f) Los Angeles Intl. Airport, CA
(g) Miami Intl. Airport, FL
(h) Newark Intl. Airport, NJ
(i) New York Kennedy Airport, NY
(j) New York La Guardia Airport, NY
(k) Ronald Reagan Washington National
Airport, DC
(l) San Francisco Intl. Airport, CA
3. No person may take off or land a civil aircraft
at an airport within Class B airspace or operate a civil
aircraft within Class B airspace unless:
(a) The pilot-in-command holds at least a
private pilot certificate; or
AIM 2/14/08
3-2-3
Controlled Airspace
(b) The aircraft is operated by a student pilot
or recreational pilot who seeks private pilot
certification and has met the requirements of 14 CFR
Section 61.95.
4. Unless otherwise authorized by ATC, each
person operating a large turbine engine-powered
airplane to or from a primary airport shall operate at
or above the designated floors while within the lateral
limits of Class B airspace.
5. Unless otherwise authorized by ATC, each
aircraft must be equipped as follows:
(a) For IFR operations, an operable VOR or
TACAN receiver; and
(b) For all operations, a two-way radio
capable of communications with ATC on appropriate
frequencies for that area; and
(c) Unless otherwise authorized by ATC, an
operable radar beacon transponder with automatic
altitude reporting equipment.
NOTE-
ATC may, upon notification, immediately authorize a
deviation from the altitude reporting equipment require-
ment; however, a request for a deviation from the 4096
transponder equipment requirement must be submitted to
the controlling ATC facility at least one hour before the
proposed operation.
REFERENCE-
AIM, Transponder Operation, Paragraph 4-1-19.
6. Mode C Veil. The airspace within 30_nauti-
cal miles of an airport listed in Appendix D, Section_1
of 14 CFR Part 91 (generally primary airports within
Class B airspace areas), from the surface upward to
10,000 feet MSL. Unless otherwise authorized by
ATC, aircraft operating within this airspace must be
equipped with automatic pressure altitude reporting
equipment having Mode_C capability.
However, an aircraft that was not originally
certificated with an engine-driven electrical system
or which has not subsequently been certified with a
system installed may conduct operations within a
Mode C veil provided the aircraft remains outside
Class A, B or C airspace; and below the altitude of the
ceiling of a Class B or Class C airspace area
designated for an airport or 10,000 feet MSL,
whichever is lower.
c. Charts. Class B airspace is charted on
Sectional Charts, IFR En Route Low Altitude, and
Terminal Area Charts.
d. Flight Procedures.
1. Flights. Aircraft within Class B airspace are
required to operate in accordance with current IFR
procedures. A clearance for a visual approach to a
primary airport is not authorization for turbinepowered airplanes to operate below the designated
floors of the Class B airspace.
2. VFR Flights.
(a) Arriving aircraft must obtain an ATC
clearance prior to entering Class B airspace and must
contact ATC on the appropriate frequency, and in
relation to geographical fixes shown on local charts.
Although a pilot may be operating beneath the floor
of the Class B airspace on initial contact,
communications with ATC should be established in
relation to the points indicated for spacing and
sequencing purposes.
(b) Departing aircraft require a clearance to
depart Class B airspace and should advise the
clearance delivery position of their intended altitude
and route of flight. ATC will normally advise VFR
aircraft when leaving the geographical limits of the
Class B airspace. Radar service is not automatically
terminated with this advisory unless specifically
stated by the controller.
(c) Aircraft not landing or departing the
primary airport may obtain an ATC clearance to
transit the Class_B airspace when traffic conditions
permit and provided the requirements of 14 CFR
Section 91.131 are met. Such VFR aircraft are
encouraged, to the extent possible, to operate at
altitudes above or below the Class B airspace or
transit through established VFR corridors. Pilots
operating in VFR corridors are urged to use frequency
122.750 MHz for the exchange of aircraft position
information.
e. ATC Clearances and Separation. An ATC
clearance is required to enter and operate within
Class_B airspace. VFR pilots are provided sequenc-
ing and separation from other aircraft while operating
within Class B airspace.
REFERENCE-
AIM, Terminal Radar Services for VFR Aircraft, Paragraph 4-1-17.
AIM 2/14/08
3-2-4 Controlled Airspace
NOTE1. Separation and sequencing of VFR aircraft will be
suspended in the event of a radar outage as this service is
dependent on radar. The pilot will be advised that the
service is not available and issued wind, runway
information and the time or place to contact the tower.
2. Separation of VFR aircraft will be suspended during
CENRAP operations. Traffic advisories and sequencing to
the primary airport will be provided on a workload
permitting basis. The pilot will be advised when center
radar presentation (CENRAP) is in use.
1. VFR aircraft are separated from all VFR/IFR
aircraft which weigh 19,000 pounds or less by a
minimum of:
(a) Target resolution, or
(b) 500 feet vertical separation, or
(c) Visual separation.
2. VFR aircraft are separated from all VFR/IFR
aircraft which weigh more than 19,000 and turbojets
by no less than:
(a) 1 1
/2 miles lateral separation, or
(b) 500 feet vertical separation, or
(c) Visual separation.
3. This program is not to be interpreted as
relieving pilots of their responsibilities to see and
avoid other traffic operating in basic VFR weather
conditions, to adjust their operations and flight path
as necessary to preclude serious wake encounters, to
maintain appropriate terrain and obstruction clear-
ance or to remain in weather conditions equal to or
better than the minimums required by 14 CFR
Section 91.155. Approach control should be advised
and a revised clearance or instruction obtained when
compliance with an assigned route, heading and/or
altitude is likely to compromise pilot responsibility
with respect to terrain and obstruction clearance,
vortex exposure, and weather minimums.
4. ATC may assign altitudes to VFR aircraft that
do not conform to 14 CFR Section 91.159.
“RESUME APPROPRIATE VFR ALTITUDES”
will be broadcast when the altitude assignment is no
longer needed for separation or when leaving Class B
airspace. Pilots must return to an altitude that
conforms to 14 CFR Section 91.159.
f. Proximity operations. VFR aircraft operating
in proximity to Class B airspace are cautioned against
operating too closely to the boundaries, especially
where the floor of the Class B airspace is 3,000 feet
or less above the surface or where VFR cruise
altitudes are at or near the floor of higher levels.
Observance of this precaution will reduce the
potential for encountering an aircraft operating at the
altitudes of Class B floors. Additionally, VFR aircraft
are encouraged to utilize the VFR Planning Chart as
a tool for planning flight in proximity to Class B
airspace. Charted VFR Flyway Planning Charts are
published on the back of the existing VFR Terminal
Area Charts.
3-2-4. Class C Airspace
a. Definition. Generally, that airspace from the
surface to 4,000 feet above the airport elevation
(charted in MSL) surrounding those airports that have
an operational control tower, are serviced by a radar
approach control, and that have a certain number of
IFR operations or passenger enplanements. Although
the configuration 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 no lower
than 1,200_feet up to 4,000 feet above the airport
elevation.
b. Charts. Class C airspace is charted on
Sectional Charts, IFR En Route Low Altitude, and
Terminal Area Charts where appropriate.
c. Operating Rules and Pilot/Equipment
Requirements:
1. Pilot Certification. No specific certifica-
tion required.
2. Equipment.
(a) Two-way radio; and
(b) Unless otherwise authorized by ATC, an
operable radar beacon transponder with automatic
altitude reporting equipment.
NOTE-
See paragraph 4-1-19, Transponder Operation, subpara-
graph f2(c) for Mode C transponder requirements for
operating above Class C airspace.
3. Arrival or Through Flight Entry Require-
ments. Two-way radio communication must be
established with the ATC facility providing ATC
services prior to entry and thereafter maintain those
communications while in Class C airspace. Pilots of
AIM 2/14/08
3-2-5
Controlled Airspace
arriving aircraft should contact the Class C airspace
ATC facility on the publicized frequency and give
their position, altitude, radar beacon code, destina-
tion, and request Class C service. Radio contact
should be initiated far enough from the Class C
airspace boundary to preclude entering Class C
airspace before two-way radio communications are
established.
NOTE1. If the controller responds to a radio call with, “(aircraft
callsign) standby,” radio communications have been
established and the pilot can enter the Class C airspace.
2. If workload or traffic conditions prevent immediate
provision of Class C services, the controller will inform the
pilot to remain outside the Class C airspace until
conditions permit the services to be provided.
3. It is important to understand that if the controller
responds to the initial radio call without using the aircraft
identification, radio communications have not been
established and the pilot may not enter the Class C
airspace.
4. Though not requiring regulatory action, Class C
airspace areas have a procedural Outer Area. Normally
this area is 20 NM from the primary Class C airspace
airport. Its vertical limit extends from the lower limits of
radio/radar coverage up to the ceiling of the approach
control's delegated airspace, excluding the Class C
airspace itself, and other airspace as appropriate. (This
outer area is not charted.)
5. Pilots approaching an airport with Class C service
should be aware that if they descend below the base altitude
of the 5 to 10 mile shelf during an instrument or visual
approach, they may encounter nontransponder, VFR
aircraft.
EXAMPLE1. “remain outside the Class Charlie
airspace and standby.”
2. “Aircraft calling Dulles approach control, standby.”
4. Departures from:
(a) A primary or satellite airport with an
operating control tower. Two-way radio communica-
tions must be established and maintained with the
control tower, and thereafter as instructed by ATC
while operating in Class C airspace.
(b) A satellite airport without an operating
control tower. Two-way radio communications must
be established as soon as practicable after departing
with the ATC facility having jurisdiction over the
Class C airspace.
5. Aircraft Speed. Unless otherwise autho-
rized or required by ATC, no person may operate an
aircraft at or below 2,500 feet above the surface
within 4 nautical miles of the primary airport of a
Class C airspace area at an indicated airspeed of more
than 200 knots (230 mph).
d. Air Traffic Services. When two-way radio
communications and radar contact are established, all
participating VFR aircraft are:
1. Sequenced to the primary airport.
2. Provided Class C services within the Class C
airspace and the outer area.
3. Provided basic radar services beyond the
outer area on a workload permitting basis. This can be
terminated by the controller if workload dictates.
e. Aircraft Separation. Separation is provided
within the Class C airspace and the outer area after
two-way radio communications and radar contact are
established. VFR aircraft are separated from IFR
aircraft within the Class C airspace by any of the
following:
1. Visual separation.
2. 500 feet vertical; except when operating
beneath a heavy jet.
3. Target resolution.
NOTE1. Separation and sequencing of VFR aircraft will be
suspended in the event of a radar outage as this service is
dependent on radar. The pilot will be advised that the
service is not available and issued wind, runway
information and the time or place to contact the tower.
2. Separation of VFR aircraft will be suspended during
CENRAP operations. Traffic advisories and sequencing to
the primary airport will be provided on a workload
permitting basis. The pilot will be advised when CENRAP
is in use.
3. Pilot participation is voluntary within the outer area
and can be discontinued, within the outer area, at the pilot's
request. Class C services will be provided in the outer area
unless the pilot requests termination of the service.
4. Some facilities provide Class C services only during
published hours. At other times, terminal IFR radar service
will be provided. It is important to note that the
communications and transponder requirements are
dependent of the class of airspace established outside of the
published hours.
AIM 2/14/08
3-2-6 Controlled Airspace
f. Secondary Airports
1. In some locations Class C airspace may
overlie the Class D surface area of a secondary
airport. In order to allow that control tower to provide
service to aircraft, portions of the overlapping
Class_C airspace may be procedurally excluded when
the secondary airport tower is in operation. Aircraft
operating in these procedurally excluded areas will
only be provided airport traffic control services when
in communication with the secondary airport tower.
2. Aircraft proceeding inbound to a satellite
airport will be terminated at a sufficient distance to
allow time to change to the appropriate tower or
advisory frequency. Class C services to these aircraft
will be discontinued when the aircraft is instructed to
contact the tower or change to advisory frequency.
3. Aircraft departing secondary controlled
airports will not receive Class C services until they
have been radar identified and two-way communica-
tions have been established with the Class C airspace
facility.
