直升机飞行手册Rotorcraft flying handbook

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pedal pressure in a clockwise system. If cruising

airspeed is the same as, or slightly above descending airspeed, simultaneously apply the necessary cyclic

pressure to obtain the approximate descending attitude.

If cruising speed is well above descending airspeed, you

can maintain a level flight attitude until the airspeed

approaches the descending airspeed, then lower the

nose to the descending attitude. Throughout the maneuver, maintain descending attitude and airspeed with the

cyclic; descending power and r.p.m. with the collective

and throttle; and heading with the antitorque pedals.

To level off from the descent, lead the desired altitude by

approximately 10 percent of the rate of descent. For example, a 500 feet per minute rate of descent would require a

50 foot lead. At this point, increase the collective to obtain

cruising power, adjust the throttle to maintain r.p.m., and

increase left antitorque pedal pressure to maintain heading

(right pedal pressure in a clockwise rotor system). Adjust

the cyclic to obtain cruising airspeed and a level flight attitude as the desired altitude is reached.

COMMON ERRORS

1. Failure to maintain constant angle of decent during training.

2. Failure to lead the level-off sufficiently, which

results in recovery below the desired altitude.

3. Failure to adjust antitorque pedal pressures for

changes in power.

GROUND REFERENCE MANEUVERS

Ground reference maneuvers are training exercises

flown to help you develop a division of attention

between the flight path and ground references, while

controlling the helicopter and watching for other aircraft in the vicinity. Prior to each maneuver, a clearing

turn should be accomplished to ensure the practice area

is free of conflicting traffic.

RECTANGULAR COURSE

The rectangular course is a training maneuver in which

the ground track of the helicopter is equidistant from

all sides of a selected rectangular area on the ground.

While performing the maneuver, the altitude and airspeed should be held constant. The rectangular course

helps you to develop a recognition of a drift toward or

away from a line parallel to the intended ground track.

This is helpful in recognizing drift toward or from an

airport runway during the various legs of the airport

traffic pattern.

For this maneuver, pick a square or rectangular field,

or an area bounded on four sides by section lines or

roads, where the sides are approximately a mile in

length. The area selected should be well away from

other air traffic. Fly the maneuver approximately 600

to 1,000 feet above the ground, which is the altitude

usually required for an airport traffic pattern. You

should fly the helicopter parallel to and at a uniform

distance, about one-fourth to one-half mile, from the

field boundaries, not above the boundaries. For best

results, position your flight path outside the field

boundaries just far enough away that they may be

easily observed from either pilot seat by looking out

the side of the helicopter. If an attempt is made to fly

directly above the edges of the field, you will have

no usable reference points to start and complete the

turns. In addition, the closer the track of the helicopter is to the field boundaries, the steeper the bank

necessary at the turning points. Also, you should be

able to see the edges of the selected field while seated

in a normal position and looking out the side of the

helicopter during either a left-hand or right-hand

course. The distance of the ground track from the

edges of the field should be the same regardless of

whether the course is flown to the left or right. All

turns should be started when your helicopter is abeam

the corners of the field boundaries. The bank normally should not exceed 30°.

Although the rectangular course may be entered from

any direction, this discussion assumes entry on a

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downwind heading. [Figure 9-15] As you approach the

field boundary on the downwind leg, you should begin

planning for your turn to the crosswind leg. Since you

have a tailwind on the downwind leg, the helicopter's

groundspeed is increased (position 1). During the turn

onto the crosswind leg, which is the equivalent of the

base leg in a traffic pattern, the wind causes the helicopter to drift away from the field. To counteract this

effect, the roll-in should be made at a fairly fast rate

with a relatively steep bank (position 2).

As the turn progresses, the tailwind component

decreases, which decreases the groundspeed.

Consequently, the bank angle and rate of turn must be

reduced gradually to ensure that upon completion of

the turn, the crosswind ground track continues to be the

same distance from the edge of the field. Upon completion of the turn, the helicopter should be level and

aligned with the downwind corner of the field.

However, since the crosswind is now pushing you

away from the field, you must establish the proper drift

correction by flying slightly into the wind. Therefore,

the turn to crosswind should be greater than a 90°

change in heading (position 3). If the turn has been

made properly, the field boundary again appears to be

one-fourth to one-half mile away. While on the crosswind leg, the wind correction should be adjusted, as

necessary, to maintain a uniform distance from the field

boundary (position 4).

As the next field boundary is being approached (position 5), plan the turn onto the upwind leg. Since a wind

correction angle is being held into the wind and toward

the field while on the crosswind leg, this next turn

requires a turn of less than 90°. Since the crosswind

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becomes a headwind, causing the groundspeed to

decrease during this turn, the bank initially must be

medium and progressively decreased as the turn proceeds. To complete the turn, time the rollout so that the

helicopter becomes level at a point aligned with the

corner of the field just as the longitudinal axis of the

helicopter again becomes parallel to the field boundary

(position 6). The distance from the field boundary

should be the same as on the other sides of the field.

On the upwind leg, the wind is a headwind, which

results in an decreased groundspeed (position 7).

Consequently, enter the turn onto the next leg with a

fairly slow rate of roll-in, and a relatively shallow bank

(position 8). As the turn progresses, gradually increase

the bank angle because the headwind component is

diminishing, resulting in an increasing groundspeed.

During and after the turn onto this leg, the wind tends

to drift the helicopter toward the field boundary. To

WIND

No Crab

Start Turn

At Boundary

Complete Turn

At Boundary

Turn less Than

90°—Roll Out

With Crab Established

Crab Into

Wind

Start Turn

At Boundary

Turn More

Than 90°

Enter

Pattern

Complete Turn

At Boundary

No Crab

Start Turn

At Boundary

Turn More Than

90°—Roll Out

With Crab Established

Complete Turn

At Boundary

Crab Into

Wind

Start Turn

At Boundary

Turn Less

Than 90°

Complete Turn

At Boundary

TrackWithNoWindCorrection

TrackWithNoWindCorrection

Figure 9-15. Rectangular course. The numbered positions in the text refer to the numbers in this illustration.

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compensate for the drift, the amount of turn must be

less than 90° (position 9).

Again, the rollout from this turn must be such that as

the helicopter becomes level, the nose of the helicopter

is turned slightly away the field and into the wind to

correct for drift. The helicopter should again be the

same distance from the field boundary and at the same

altitude, as on other legs. Continue the crosswind leg

until the downwind leg boundary is approached (position 10). Once more you should anticipate drift and

turning radius. Since drift correction was held on the

crosswind leg, it is necessary to turn greater than 90° to

align the helicopter parallel to the downwind leg

boundary. Start this turn with a medium bank angle,

gradually increasing it to a steeper bank as the turn progresses. Time the rollout to assure paralleling the

boundary of the field as the helicopter becomes level

(position 11).

If you have a direct headwind or tailwind on the

upwind and downwind leg, drift should not be encountered. However, it may be difficult to find a situation

where the wind is blowing exactly parallel to the field

boundaries. This makes it necessary to use a slight

wind correction angle on all the legs. It is important to

anticipate the turns to compensate for groundspeed,

drift, and turning radius. When the wind is behind the

helicopter, the turn is faster and steeper; when it is

ahead of the helicopter, the turn is slower and

shallower. These same techniques apply while flying in

an airport traffic pattern.

S-TURNS

Another training maneuver you might use is the S-turn,

which helps you correct for wind drift in turns. This

maneuver requires turns to the left and right. The reference line used, whether a road, railroad, or fence, should

be straight for a considerable distance and should

extend as nearly perpendicular to the wind as possible.

The object of S-turns is to fly a pattern of two half circles of equal size on opposite sides of the reference line.

[Figure 9-16] The maneuver should be performed at a

constant altitude between 600 and 1,000 feet above the

terrain. S-turns may be started at any point; however,

during early training it may be beneficial to start on a

downwind heading. Entering downwind permits the

immediate selection of the steepest bank that is desired

throughout the maneuver. The discussion that follows is

based on choosing a reference line that is perpendicular

to the wind and starting the maneuver on a downwind

heading.

As the helicopter crosses the reference line, immediately establish a bank. This initial bank is the steepest

used throughout the maneuver since the helicopter is

headed directly downwind and the groundspeed is at its

highest. Gradually reduce the bank, as necessary, to

describe a ground track of a half circle. Time the turn

so that as the rollout is completed, the helicopter is

crossing the reference line perpendicular to it and heading directly upwind. Immediately enter a bank in the

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opposite direction to begin the second half of the “S.”

Since the helicopter is now on an upwind heading, this

bank (and the one just completed before crossing the

reference line) is the shallowest in the maneuver.

Gradually increase the bank, as necessary, to describe a

ground track that is a half circle identical in size to the

one previously completed on the other side of the reference line. The steepest bank in this turn should be

attained just prior to rollout when the helicopter is

approaching the reference line nearest the downwind

heading. Time the turn so that as the rollout is complete, the helicopter is perpendicular to the reference

line and is again heading directly downwind.

In summary, the angle of bank required at any given

point in the maneuver is dependent on the groundspeed. The faster the groundspeed, the steeper the

bank; the slower the groundspeed, the shallower

the bank. To express it another way, the more nearly

the helicopter is to a downwind heading, the steeper the

bank; the more nearly it is to an upwind heading,

the shallower the bank. In addition to varying the angle

of bank to correct for drift in order to maintain the

proper radius of turn, the helicopter must also be flown

with a drift correction angle (crab) in relation to its

ground track; except of course, when it is on direct

upwind or downwind headings or there is no wind. One

would normally think of the fore and aft axis of the helicopter as being tangent to the ground track pattern at

each point. However, this is not the case. During the turn

on the upwind side of the reference line (side from

which the wind is blowing), crab the nose of the helicopter toward the outside of the circle. During the turn

on the downwind side of the reference line (side of the

reference line opposite to the direction from which the

wind is blowing), crab the nose of the helicopter toward

the inside of the circle. In either case, it is obvious that

Points of

Shallowest Bank

Points of

Steepest Bank

WIND

Figure 9-16. S-turns across a road.

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the helicopter is being crabbed into the wind just as it is

when trying to maintain a straight ground track. The

amount of crab depends upon the wind velocity and

how nearly the helicopter is to a crosswind position.

The stronger the wind, the greater the crab angle at any

given position for a turn of a given radius. The more

nearly the helicopter is to a crosswind position, the

greater the crab angle. The maximum crab angle should

be at the point of each half circle farthest from the

reference line.

A standard radius for S-turns cannot be specified, since

the radius depends on the airspeed of the helicopter,

the velocity of the wind, and the initial bank chosen

for entry.

TURNS AROUND A POINT

This training maneuver requires you to fly constant

radius turns around a preselected point on the ground

using a bank of approximately 30°, while maintaining

a constant altitude. [Figure 9-17] Your objective, as in

other ground reference maneuvers, is to develop the

ability to subconsciously control the helicopter while

dividing attention between the flight path and ground

references, while still watching for other air traffic in

the vicinity.

The factors and principles of drift correction that are

involved in S-turns are also applicable in this maneuver. As in other ground track maneuvers, a constant

radius around a point will, if any wind exists, require

a constantly changing angle of bank and angles of

wind correction. The closer the helicopter is to a

direct downwind heading where the groundspeed is

greatest, the steeper the bank, and the faster the rate

of turn required to establish the proper wind correction angle. The more nearly it is to a direct upwind

heading where the groundspeed is least, the shallower

the bank, and the slower the rate of turn required to

establish the proper wind correction angle. It follows,

then, that throughout the maneuver, the bank and rate

of turn must be gradually varied in proportion to the

groundspeed.

The point selected for turns around a point should be

prominent and easily distinguishable, yet small enough

to present a precise reference. Isolated trees, crossroads,

or other similar small landmarks are usually suitable.

The point should be in an area away from communities,

livestock, or groups of people on the ground to prevent

possible annoyance or hazard to others. Since the

maneuver is performed between 600 and 1,000 feet

AGL, the area selected should also afford an opportunity for a safe emergency autorotation in the event it

becomes necessary.

To enter turns around a point, fly the helicopter on a

downwind heading to one side of the selected point

at a distance equal to the desired radius of turn. When

any significant wind exists, it is necessary to roll into

the initial bank at a rapid rate so that the steepest

bank is attained abeam the point when the helicopter

is headed directly downwind. By entering the maneuver while heading directly downwind, the steepest

bank can be attained immediately. Thus, if a bank of

30° is desired, the initial bank is 30° if the helicopter

is at the correct distance from the point. Thereafter,

the bank is gradually shallowed until the point is

reached where the helicopter is headed directly

upwind. At this point, the bank is gradually steepened

until the steepest bank is again attained when heading downwind at the initial point of entry.

Just as S-turns require that the helicopter be turned

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into the wind in addition to varying the bank, so do

turns around a point. During the downwind half of the

circle, the helicopter’s nose must be progressively

turned toward the inside of the circle; during the

upwind half, the nose must be progressively turned

toward the outside. The downwind half of the turn

around the point may be compared to the downwind

side of the S-turn, while the upwind half of the turn

around a point may be compared to the upwind side

of the S-turn.

As you become experienced in performing turns

around a point and have a good understanding of the

effects of wind drift and varying of the bank angle

and wind correction angle as required, entry into the

maneuver may be from any point. When entering

this maneuver at any point, the radius of the turn

UPPERHALFOFCIRCLE

DOWNWINDHALFOFCIRCLE

Shallowest

Bank

Steeper

Bank

Steepest

Bank

Shallower

Bank

WIND

Figure 9-17. Turns around a point.

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must be carefully selected, taking into account the

wind velocity and groundspeed so that an excessive

bank is not required later on to maintain the proper

ground track.

COMMON ERRORS DURING GROUND

REFERENCE MANEUVERS

1. Faulty entry technique.

2. Poor planning, orientation, or division of

attention.

3. Uncoordinated flight control application.

4. Improper correction for wind drift.

5. An unsymmetrical ground track during S-Turns

Across a Road.

6. Failure to maintain selected altitude or airspeed.

7. Selection of a ground reference where there is no

suitable emergency landing area within gliding

distance.

TRAFFIC PATTERNS

A traffic pattern is useful to control the flow of traffic, particularly at airports without operating control towers. It

affords a measure of safety, separation, protection, and

administrative control over arriving, departing, and

circling aircraft. Due to specialized operating characteristics, airplanes and helicopters do not mix well in the

same traffic environment. At multiple-use airports,

you routinely must avoid the flow of fixed-wing traffic. To do this, you need to be familiar with the

patterns typically flown by airplanes. In addition, you

should learn how to fly these patterns in case air traffic control (ATC) requests that you fly a fixed-wing

traffic pattern.

A normal traffic pattern is rectangular, has five named

legs, and a designated altitude, usually 600 to 1,000

feet AGL. A pattern in which all turns are to the left is

called a standard pattern. [Figure 9-18] The takeoff leg

(item 1) normally consists of the aircraft’s flight path

after takeoff. This leg is also called the upwind leg. You

should turn to the crosswind leg (item 2), after passing

the departure end of the runway when you are at a safe

altitude. Fly the downwind leg (item 3) parallel to the

runway at the designated traffic pattern altitude and

distance from the runway. Begin the base leg (item 4)

at a point selected according to other traffic and wind

conditions. If the wind is very strong, begin the turn

sooner than normal. If the wind is light, delay the turn

to base. The final approach (item 5) is the path the aircraft flies immediately prior to touchdown.

You may find variations at different localities and at

airports with operating control towers. For example, a

right-hand pattern may be designated to expedite the

flow of traffic when obstacles or highly populated areas

make the use of a left-hand pattern undesirable.

When approaching an airport with an operating control

tower in a helicopter, it is possible to expedite traffic by

stating your intentions, for example:

1. (Call sign of helicopter) Robinson 8340J.

2. (Position) 10 miles west.

3. (Request) for landing and hover to...

In order to avoid the flow of fixed-wing traffic, the

tower will often clear you direct to an approach point

or to a particular runway intersection nearest your

destination point. At uncontrolled airports, if at all

possible, you should adhere to standard practices

and patterns.

Traffic pattern entry procedures at airports with an

operating control tower are specified by the controller.

At uncontrolled airports, traffic pattern altitudes and

entry procedures may vary according to established

local procedures. The general procedure is for you to

enter the pattern at a 45° angle to the downwind leg

abeam the midpoint of the runway. For information

concerning traffic pattern and landing direction, you

should utilize airport advisory service or UNICOM,

when available.

The standard departure procedure when using the

fixed-wing traffic pattern is usually straight-out, downwind, or a right-hand departure. When a control tower

is in operation, you can request the type of departure

you desire. In most cases, helicopter departures are

made into the wind unless obstacles or traffic dictate

otherwise. At airports without an operating control

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tower, you must comply with the departure procedures

established for that airport.

Downwind Leg

Base Leg

Final Approach

Leg

Takeoff Leg

(Upwind)

Crosswind Leg

Figure 9-18. A standard traffic pattern has turns to left and

five designated legs.

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APPROACHES

An approach is the transition from traffic pattern altitude to either a hover or to the surface. The approach

should terminate at the hover altitude with the rate of

descent and groundspeed reaching zero at the same

time. Approaches are categorized according to the angle

of descent as normal, steep, or shallow. In this chapter

we will concentrate on the normal approach. Steep and

shallow approaches are discussed in the next chapter.

You should use the type of approach best suited to the

existing conditions. These conditions may include

obstacles, size and surface of the landing area, density

altitude, wind direction and speed, and weight.

Regardless of the type of approach, it should always

be made to a specific, predetermined landing spot.

NORMAL APPROACH TO A HOVER

A normal approach uses a descent profile of between

8° and 12° starting at approximately 300 feet AGL.

TECHNIQUE

On final approach, at the recommended approach

airspeed and at approximately 300 feet AGL, align the

helicopter with the point of intended touchdown.

[Figure 9-19] After intercepting an approach angle of 8°

to 12°, begin the approach by lowering the collective

sufficiently to get the helicopter decelerating and

descending down the approach angle. With the decrease

in the collective, the nose tends to pitch down, requiring

aft cyclic to maintain the recommended approach airspeed attitude. Adjust antitorque pedals, as necessary, to

maintain longitudinal trim. You can determine the proper

approach angle by relating the point of intended

touchdown to a point on the helicopter windshield. The

collective controls the angle of approach. If the touchdown point seems to be moving up on the windshield, the

angle is becoming shallower, necessitating a slight

increase in collective. If the touchdown point moves

down on the windshield, the approach angle is becoming

steeper, requiring a slight decrease in collective. Use the

cyclic to control the rate of closure or how fast your are

moving toward the touchdown point. Maintain entry

airspeed until the apparent groundspeed and rate of

closure appear to be increasing. At this point, slowly

begin decelerating with slight aft cyclic, and smoothly

lower the collective to maintain approach angle. Use the

cyclic to maintain a rate of closure equivalent to a

brisk walk.

At approximately 25 to 40 feet AGL, depending on wind,

the helicopter begins to lose effective translational lift. To

compensate for loss of effective translational lift, you

must increase the collective to maintain the approach

angle, while maintaining the proper r.p.m. The increase

of collective pitch tends to make the nose rise, requiring

forward cyclic to maintain the proper rate of closure.

As the helicopter approaches the recommended hover

altitude, you need to increase the collective sufficiently

to maintain the hover. At the same time you need to

apply aft cyclic to stop any forward movement, while

controlling the heading with antitorque pedals.

COMMON ERRORS

1. Failing to maintain proper r.p.m. during the entire

approach.

2. Improper use of the collective in controlling the

angle of descent.

3. Failing to make antitorque pedal corrections to

compensate for collective changes during the

approach.

4. Failing to simultaneously arrive at hovering altitude and attitude with zero groundspeed.

5. Low r.p.m. in transition to the hover at the end of

the approach.

6. Using too much aft cyclic close to the surface,

which may result in tail rotor strikes.

H

Imaginary

Centerline

Figure 9-19. Plan the turn to final so the helicopter rolls out

on an imaginary extension of the centerline for the final

approach path. This path should neither angle to the landing area, as shown by the helicopter on the left, nor require

an S-turn, as shown by the helicopter on the right.

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NORMAL APPROACH TO THE SURFACE

A normal approach to the surface or a no-hover landing is

used if loose snow or dusty surface conditions exist.

These situations could cause severely restricted visibility,

or the engine could possibly ingest debris when the helicopter comes to a hover. The approach is the same as the

normal approach to a hover; however, instead of terminating at a hover, continue the approach to touchdown.

Touchdown should occur with the skids level, zero

groundspeed, and a rate of descent approaching zero.

TECHNIQUE:

As the helicopter nears the surface, increase the collective, as necessary, to cushion the landing on the surface, terminate in a skids-level attitude with no forward

movement.

COMMON ERRORS

1. Terminating at a hover, then making a vertical

landing.

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2. Touching down with forward movement.

3. Approaching too slow, requiring the use of excessive power during the termination.

4. Approaching too fast, causing a hard landing.

CROSSWIND DURING APPROACHES

During a crosswind approach, you should crab into the

wind. At approximately 50 feet of altitude, use a slip to

align the fuselage with the ground track. The rotor is

tilted into the wind with cyclic pressure so that the

sideward movement of the helicopter and wind drift

counteract each other. Maintain the heading and ground

track with the antitorque pedals. This technique should

be used on any type of crosswind approach, whether it is

a shallow, normal, or steep approach.

GO-AROUND

A go-around is a procedure for remaining airborne after

an intended landing is discontinued. A go-around may

be necessary when:

• Instructed by the control tower.

• Traffic conflict occurs.

A good rule of thumb to use during an approach is to

make a go-around if the helicopter is in a position from

which it is not safe to continue the approach. Anytime

you feel an approach is uncomfortable, incorrect, or

potentially dangerous, abandon the approach. The decision to make a go-around should be positive and initiated

before a critical situation develops. When the decision is

made, carry it out without hesitation. In most cases, when

you initiate the go-around, power is at a low setting.

Therefore, your first response is to increase collective to

takeoff power. This movement is coordinated with the

throttle to maintain r.p.m., and the proper antitorque pedal

to control heading. Then, establish a climb attitude and

maintain climb speed to go around for another approach.

AFTER LANDING AND SECURING

When the flight is terminated, park the helicopter

where it will not interfere with other aircraft and not

be a hazard to people during shutdown. Rotor downwash can cause damage to other aircraft in close

proximity, and spectators may not realize the danger

or see the rotors turning. Passengers should remain in

the helicopter with their seats belts secured until the

rotors have stopped turning. During the shutdown

and postflight inspection, follow the manufacturer’s

checklist. Any discrepancies found should be noted

and, if necessary, reported to maintenance personnel.

NOISE ABATEMENT PROCEDURES

The FAA, in conjunction with airport operators and

community leaders, is now using noise abatement

procedures to reduce the level of noise generated by

aircraft departing over neighborhoods that are near

airports. The airport authority may simply request that

you use a designated runway, wind permitting. You

also may be asked to restrict some of your operations,

such as practicing landings, during certain time periods. There are three ways to determine the noise abatement procedure at an airport. First, if there is a control

tower on the field, they will assign the preferred noise

abatement runway or takeoff direction to you. Second,

you can check the Airport/Facility Directory for information on local procedures. Third, there may be information for you to read in the pilot’s lounge, or even

signs posted next to a runway that will advise you on

local procedures.

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The maneuvers presented in this chapter require more

finesse and understanding of the helicopter and the

surrounding environment. When performing these

maneuvers, you will probably be taking your helicopter

to the edge of the safe operating envelope. Therefore, if

you are ever in doubt about the outcome of the maneuver,

you should abort the mission entirely or wait for more

favorable conditions.

RECONNAISSANCE PROCEDURES

Anytime you are planning to land or takeoff at an unfamiliar site, you should gather as much information as

you can about the area. Reconnaissance techniques are

ways of gathering this information.

HIGH RECONNAISSANCE

The purpose of a high reconnaissance is to determine

the wind direction and speed, a point for touchdown,

the suitability of the landing area, the approach and

departure axes, obstacles and their effect on wind patterns, and the most suitable flight paths into and out of

the area. When conducting a high reconnaissance, give

particular consideration to forced landing areas in case

of an emergency.

Altitude, airspeed, and flight pattern for a high reconnaissance are governed by wind and terrain features.

You must strike a balance between a reconnaissance

conducted too high and one too low. It should not be

flown so low that you have to divide your attention

between studying the area and avoiding obstructions to

flight. A high reconnaissance should be flown at an altitude of 300 to 500 feet above the surface. A general rule

to follow is to ensure that sufficient altitude is available

at all times to land into the wind in case of engine failure. In addition, a 45° angle of observation generally

allows the best estimate of the height of barriers, the

presence of obstacles, the size of the area, and the slope

of the terrain. Always maintain safe altitudes and airspeeds, and keep a forced landing area within reach

whenever possible.

LOW RECONNAISSANCE

A low reconnaissance is accomplished during the

approach to the landing area. When flying the

approach, verify what was observed in the high reconnaissance, and check for anything new that may have

been missed at a higher altitude, such as wires, slopes,

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and small crevices. If everything is alright, you can

complete the approach to a landing. However, you must

make the decision to land or go-around before effective

translational lift is lost.

If a decision is made to complete the approach, terminate it in a hover, so you can carefully check the

landing point before lowering the helicopter to the

surface. Under certain conditions, it may be desirable

to continue the approach to the surface. Once the helicopter is on the ground, maintain operating r.p.m. until

you have checked the stability of the helicopter to be

sure it is in a secure and safe position.

GROUND RECONNAISSANCE

Prior to departing an unfamiliar location, make a

detailed analysis of the area. There are several factors

to consider during this evaluation. Besides determining

the best departure path, you must select a route that will

get your helicopter from its present position to the takeoff point.

Some things to consider while formulating a takeoff

plan are the aircraft load, height of obstacles, the shape

of the area, and direction of the wind. If the helicopter is

heavily loaded, you must determine if there is sufficient

power to clear the obstacles. Sometimes it is better to

pick a path over shorter obstacles than to take off

directly into the wind. You should also evaluate the

shape of the area so that you can pick a path that will

give you the most room to maneuver and abort the takeoff if necessary. Wind analysis also helps determine the

route of takeoff. The prevailing wind can be altered by

obstructions on the departure path, and can significantly

affect aircraft performance. One way to determine the

wind direction is to drop some dust or grass, and

observe which way it is blowing. Keep in mind that if

the main rotor is turning, you will need to be a sufficient

distance from the helicopter to ensure that the downwash of the blades does not give you a false indication.

If possible, you should walk the route from the helicopter to the takeoff position. Evaluate obstacles that could

be hazardous and ensure that you will have adequate

rotor clearance. Once at the downwind end of the available area, mark a position for takeoff so that the tail and

main rotors have sufficient clearance from any obstructions behind the helicopter. Use a sturdy marker, such

as a heavy stone or log, so it does not blow away.

10-2

MAXIMUM PERFORMANCE TAKEOFF

A maximum performance takeoff is used to climb at a

steep angle to clear barriers in the flight path. It can be

used when taking off from small areas surrounded by

high obstacles. Before attempting a maximum

performance takeoff, you must know thoroughly the

capabilities and limitations of your equipment. You

must also consider the wind velocity, temperature, altitude, gross weight, center-of-gravity location, and

other factors affecting your technique and the performance of the helicopter.

To safely accomplish this type of takeoff, there must be

enough power to hover, in order to prevent the helicopter from sinking back to the surface after becoming

airborne. This hover power check can be used to determine if there is sufficient power available to accomplish

this maneuver.

The angle of climb for a maximum performance takeoff depends on existing conditions. The more critical

the conditions, such as high density altitudes, calm

winds, and high gross weights, the shallower the angle

of climb. In light or no wind conditions, it might be

necessary to operate in the crosshatched or shaded

areas of the height/velocity diagram during the beginning of this maneuver. Therefore, be aware of the

calculated risk when operating in these areas. An

engine failure at a low altitude and airspeed could place

the helicopter in a dangerous position, requiring a high

degree of skill in making a safe autorotative landing.

TECHNIQUE

Before attempting a maximum performance takeoff,

bring the helicopter to a hover, and determine the

excess power available by noting the difference

between the power available and that required to hover.

You should also perform a balance and flight control

check and note the position of the cyclic. Then position

the helicopter into the wind and return the helicopter to

the surface. Normally, this maneuver is initiated from

the surface. After checking the area for obstacles and

other aircraft, select reference points along the takeoff

path to maintain ground track. You should also consider

alternate routes in case you are not able to complete the

maneuver. [Figure 10-1]

Begin the takeoff by getting the helicopter light on the

skids (position 1). Pause and neutralize all aircraft movement. Slowly increase the collective and position the

cyclic so as to break ground in a 40 knot attitude. This is

approximately the same attitude as when the helicopter is

light on the skids. Continue to slowly increase the collective until the maximum power available is reached. This

large collective movement requires a substantial increase

in pedal pressure to maintain heading (position 2). Use the

cyclic, as necessary, to control movement toward the

desired flight path and, therefore, climb angle during the

maneuver (position 3). Maintain rotor r.p.m. at its maximum, and do not allow it to decrease since you would

probably have to lower the collective to regain it. Maintain

these inputs until the helicopter clears the obstacle, or until

reaching 50 feet for demonstration purposes (position 4).

Then, establish a normal climb attitude and reduce power

(position 5). As in any maximum performance maneuver,

the techniques you use affect the actual results. Smooth,

coordinated inputs coupled with precise control allow the

helicopter to attain its maximum performance.

帅哥

COMMON ERRORS

1. Failure to consider performance data, including

height/velocity diagram.

2. Nose too low initially, causing horizontal flight

rather than more vertical flight.

3. Failure to maintain maximum permissible r.p.m.

4. Abrupt control movements.

5. Failure to resume normal climb power and airspeed after clearing the obstacle.

RUNNING/ROLLING TAKEOFF

A running takeoff in a skid-type helicopter or a rolling

takeoff in a wheeled helicopter is sometimes used when

conditions of load and/or density altitude prevent a sustained hover at normal hovering altitude. However, you

should not attempt this maneuver if you do not have

sufficient power to hover, at least momentarily. If the

helicopter cannot be hovered, its performance is unpredictable. If the helicopter cannot be raised off the

surface at all, sufficient power might not be available

to safely accomplish the maneuver. If you cannot

momentarily hover the helicopter, you must wait for

conditions to improve or off-load some of the weight.

To accomplish a safe running or rolling takeoff, the surface area must be of sufficient length and smoothness,

and there cannot be any barriers in the flight path to

interfere with a shallow climb.

For wheeled helicopters, a rolling takeoff is sometimes

used to minimize the downwash created during a takeoff from a hover. Figure 10-1. Maximum performance takeoff.

10-3

TECHNIQUE

Refer to figure 10-2. To begin the maneuver, first align

the helicopter to the takeoff path. Next, increase the

throttle to obtain takeoff r.p.m., and increase the collective smoothly until the helicopter becomes light on the

skids or landing gear (position 1). Then, move the

cyclic slightly forward of the neutral hovering position,

and apply additional collective to start the forward

movement (position 2). To simulate a reduced power

condition during practice, use one to two inches less

manifold pressure, or three to five percent less torque,

than that required to hover.

Maintain a straight ground track with lateral cyclic and

heading with antitorque pedals until a climb is established.

As effective translational lift is gained, the helicopter

becomes airborne in a fairly level attitude with little or no

pitching (position 3). Maintain an altitude to take advantage of ground effect, and allow the airspeed to increase

toward normal climb speed. Then, follow a climb profile

that takes you through the clear area of the height/velocity

diagram (position 4). During practice maneuvers, after

you have climbed to an altitude of 50 feet, establish the

normal climb power setting and attitude.

COMMON ERRORS

1. Failing to align heading and ground track to keep

surface friction to a minimum.

2. Attempting to become airborne before obtaining

effective translational lift.

3. Using too much forward cyclic during the surface

run.

4. Lowering the nose too much after becoming airborne, resulting in the helicopter settling back to

the surface.

5. Failing to remain below the recommended altitude

until airspeed approaches normal climb speed.

RAPID DECELERATION (QUICK STOP)

In normal operations, use the rapid deceleration or quick

stop maneuver to slow the helicopter rapidly and bring

it to a stationary hover. The maneuver requires a high

degree of coordination of all controls. It is practiced at

an altitude that permits a safe clearance between the tail

rotor and the surface throughout the maneuver, especially at the point where the pitch attitude is highest.

The altitude at completion should be no higher than the

maximum safe hovering altitude prescribed by the manufacturer. In selecting an altitude at which to begin the

maneuver, you should take into account the overall

length of the helicopter and the height/velocity diagram.

Even though the maneuver is called a rapid deceleration

or quick stop, it is performed slowly and smoothly with

the primary emphasis on coordination.

TECHNIQUE

During training always perform this maneuver into the

wind. [Figure 10-3, position 1] After leveling off at an

altitude between 25 and 40 feet, depending on the manufacturer’s recommendations, accelerate to the desired

entry speed, which is approximately 45 knots for most

training helicopters (position 2). The altitude you

choose should be high enough to avoid danger to the

tail rotor during the flare, but low enough to stay out of

the crosshatched or shaded areas of the height/velocity

diagram throughout the maneuver. In addition, this

altitude should be low enough that you can bring the

helicopter to a hover during the recovery.

Figure 10-2. Running/rolling takeoff.

Figure 10-3. Rapid deceleration or quick stop.

10-4

At position 3, initiate the deceleration by applying aft

cyclic to reduce forward speed. Simultaneously, lower

the collective, as necessary, to counteract any climbing

tendency. The timing must be exact. If you apply too

little down collective for the amount of aft cyclic

applied, a climb results. If you apply too much down

collective, a descent results. A rapid application of aft

cyclic requires an equally rapid application of down

collective. As collective pitch is lowered, apply proper

antitorque pedal pressure to maintain heading, and

adjust the throttle to maintain r.p.m.

帅哥

After attaining the desired speed (position 4), initiate

the recovery by lowering the nose and allowing the helicopter to descend to a normal hovering altitude in level

flight and zero groundspeed (position 5). During the

recovery, increase collective pitch, as necessary, to stop

the helicopter at normal hovering altitude, adjust the

throttle to maintain r.p.m., and apply proper pedal pressure, as necessary, to maintain heading.

COMMON ERRORS

1. Initiating the maneuver by applying down

collective.

2. Initially applying aft cyclic stick too rapidly,

causing the helicopter to balloon.

3. Failing to effectively control the rate of deceleration to accomplish the desired results.

4. Allowing the helicopter to stop forward motion

in a tail-low attitude.

5. Failing to maintain proper r.p.m.

6. Waiting too long to apply collective pitch (power)

during the recovery, resulting in excessive manifold pressure or an over-torque situation when

collective pitch is applied rapidly.

7. Failing to maintain a safe clearance over the

terrain.

8. Improper use of antitorque pedals resulting in

erratic heading changes.

STEEP APPROACH TO A HOVER

A steep approach is used primarily when there are

obstacles in the approach path that are too high to allow

a normal approach. A steep approach permits entry into

most confined areas and is sometimes used to avoid

areas of turbulence around a pinnacle. An approach

angle of approximately 15° is considered a steep

approach. [Figure 10-4]

TECHNIQUE

On final approach, head your helicopter into the wind

and align it with the intended touchdown point at the

recommended approach airspeed (position 1). When

you intercept an approach angle of 15°, begin the

approach by lowering the collective sufficiently to

start the helicopter descending down the approach

path and decelerating (position 2). Use the proper

antitorque pedal for trim. Since this angle is steeper

than a normal approach angle, you need to reduce the

collective more than that required for a normal

approach. Continue to decelerate with slight aft

cyclic, and smoothly lower the collective to maintain

the approach angle. As in a normal approach,

reference the touchdown point on the windshield to

determine changes in approach angle. This point is in

a lower position than a normal approach. Aft cyclic is

required to decelerate sooner than a normal approach,

and the rate of closure becomes apparent at a higher

altitude. Maintain the approach angle and rate of

descent with the collective, rate of closure with the

cyclic, and trim with antitorque pedals. Use a crab

above 50 feet and a slip below 50 feet for any crosswind that might be present.

Loss of effective translational lift occurs higher in a

steep approach (position 3), requiring an increase in the

collective to prevent settling, and more forward cyclic

to achieve the proper rate of closure. Terminate the

approach at hovering altitude above the intended landing point with zero groundspeed (position 4). If power

has been properly applied during the final portion of

the approach, very little additional power is required in

the hover.

15° Descent

Figure 10-4. Steep approach to a hover.

Balloon—Gaining an excessive amount of altitude as a result of an

abrupt flare.

10-5

COMMON ERRORS

1. Failing to maintain proper r.p.m. during the entire

approach.

2. Improper use of collective in maintaining the

selected angle of descent.

3. Failing to make antitorque pedal corrections to

compensate for collective pitch changes during

the approach.

4. Slowing airspeed excessively in order to remain

on the proper angle of descent.

5. Inability to determine when effective translational lift is lost.

6. Failing to arrive at hovering altitude and attitude,

and zero groundspeed almost simultaneously.

7. Low r.p.m. in transition to the hover at the end of

the approach.

8. Using too much aft cyclic close to the surface,

which may result in the tail rotor striking the surface.

SHALLOW APPROACH AND

RUNNING/ROLL-ON LANDING

Use a shallow approach and running landing when a

high-density altitude or a high gross weight condition,

or some combination thereof, is such that a normal or

steep approach cannot be made because of insufficient

power to hover. [Figure 10-5] To compensate for this

lack of power, a shallow approach and running landing

makes use of translational lift until surface contact is

made. If flying a wheeled helicopter, you can also use a

roll-on landing to minimize the effect of downwash.

The glide angle for a shallow approach is approximately 5°. Since the helicopter will be sliding or rolling

to a stop during this maneuver, the landing area must

be smooth and long enough to accomplish this task.

TECHNIQUE

A shallow approach is initiated in the same manner as

the normal approach except that a shallower angle of

descent is maintained. The power reduction to initiate

the desired angle of descent is less than that for a normal

approach since the angle of descent is less (position 1).

帅哥

As you lower the collective, maintain heading with

proper antitorque pedal pressure, and r.p.m. with the

throttle. Maintain approach airspeed until the apparent

rate of closure appears to be increasing. Then, begin to

slow the helicopter with aft cyclic (position 2).

As in normal and steep approaches, the primary control

for the angle and rate of descent is the collective, while

the cyclic primarily controls the groundspeed.

However, there must be a coordination of all the controls for the maneuver to be accomplished successfully.

The helicopter should arrive at the point of touchdown

at or slightly above effective translational lift. Since

translational lift diminishes rapidly at slow airspeeds,

the deceleration must be smoothly coordinated, at the

same time keeping enough lift to prevent the helicopter

from settling abruptly.

Just prior to touchdown, place the helicopter in a level

attitude with the cyclic, and maintain heading with the

antitorque pedals. Use the cyclic to keep the heading

and ground track identical (position 3). Allow the

helicopter to descend gently to the surface in a straightand-level attitude, cushioning the landing with the

collective. After surface contact, move the cyclic

slightly forward to ensure clearance between the

tailboom and the rotor disc. You should also use the

cyclic to maintain the surface track. (position 4). You

normally hold the collective stationary until the helicopter stops; however, if you want more braking action,

you can lower the collective slightly. Keep in mind that

due to the increased ground friction when you lower the

collective, the helicopter’s nose might pitch forward.

Exercise caution not to correct this pitching movement

with aft cyclic since this movement could result in the

rotor making contact with the tailboom. During the

landing, maintain normal r.p.m. with the throttle and

directional control with the antitorque pedals.

For wheeled helicopters, use the same technique except

after landing, lower the collective, neutralize the

controls, and apply the brakes, as necessary, to slow the

helicopter. Do not use aft cyclic when bringing the

helicopter to a stop.

COMMON ERRORS

1. Assuming excessive nose-high attitude to slow

the helicopter near the surface.

2. Insufficient collective and throttle to cushion

landing.

3. Failing to add proper antitorque pedal as collective is added to cushion landing, resulting in a

touchdown while the helicopter is moving sideward.

4. Failing to maintain a speed that takes advantage

of effective translational lift.

5° Descent

Figure 10-5. Shallow approach and running landing.

10-6

5. Touching down at an excessive groundspeed for

the existing conditions. (Some helicopters have

maximum touchdown groundspeeds.)

6. Failing to touch down in a level attitude.

7. Failing to maintain proper r.p.m. during and after

touchdown.

8. Poor directional control during touchdown.

SLOPE OPERATIONS

Prior to conducting any slope operations, you should

be thoroughly familiar with the characteristics of

dynamic rollover and mast bumping, which are discussed in Chapter 11—Helicopter Emergencies. The

approach to a slope is similar to the approach to any

other landing area. During slope operations, make

allowances for wind, barriers, and forced landing sites

in case of engine failure. Since the slope may constitute

an obstruction to wind passage, you should anticipate

turbulence and downdrafts.

SLOPE LANDING

You usually land a helicopter across the slope rather

than with the slope. Landing with the helicopter facing

down the slope or downhill is not recommended

because of the possibility of striking the tail rotor on

the surface.

TECHNIQUE

Refer to figure 10-6. At the termination of the

approach, move the helicopter slowly toward the slope,

being careful not to turn the tail upslope. Position the

helicopter across the slope at a stabilized hover headed

into the wind over the spot of intended landing

(frame 1). Downward pressure on the collective starts

the helicopter descending. As the upslope skid touches

the ground, hesitate momentarily in a level attitude,

then apply lateral cyclic in the direction of the slope

(frame 2). This holds the skid against the slope while

you continue lowering the downslope skid with the collective. As you lower the collective, continue to move

the cyclic toward the slope to maintain a fixed position

(frame 3). The slope must be shallow enough so you

can hold the helicopter against it with the cyclic during

the entire landing. A slope of 5° is considered maximum for normal operation of most helicopters.

You should be aware of any abnormal vibration or mast

bumping that signals maximum cyclic deflection. If

this occurs, abandon the landing because the slope is

too steep. In most helicopters with a counterclockwise

rotor system, landings can be made on steeper slopes

when you are holding the cyclic to the right. When

landing on slopes using left cyclic, some cyclic input

must be used to overcome the translating tendency. If

wind is not a factor, you should consider the drifting

tendency when determining landing direction.

After the downslope skid is on the surface, reduce the

collective to full down, and neutralize the cyclic and

pedals (frame 4). Normal operating r.p.m. should be

maintained until the full weight of the helicopter is on

the landing gear. This ensures adequate r.p.m. for

immediate takeoff in case the helicopter starts sliding

down the slope. Use antitorque pedals as necessary

throughout the landing for heading control. Before

reducing the r.p.m., move the cyclic control as necessary to check that the helicopter is firmly on the

ground.

COMMON ERRORS

1. Failure to consider wind effects during the

approach and landing.

2. Failure to maintain proper r.p.m. throughout the

entire maneuver.

3. Turning the tail of the helicopter into the slope.

4. Lowering the downslope skid or wheel too rapidly.

5. Applying excessive cyclic control into the slope,

causing mast bumping.

SLOPE TAKEOFF

A slope takeoff is basically the reverse of a slope landing. [Figure 10-7] Conditions that may be associated

with the slope, such as turbulence and obstacles, must

Figure 10-6. Slope landing.

10-7

be considered during the takeoff. Planning should

include suitable forced landing areas.

TECHNIQUE

Begin the takeoff by increasing r.p.m. to the normal

range with the collective full down. Then, move the

cyclic toward the slope (frame 1). Holding cyclic

toward the slope causes the downslope skid to rise as

you slowly raise the collective (frame 2). As the skid

comes up, move the cyclic toward the neutral position.

If properly coordinated, the helicopter should attain a

level attitude as the cyclic reaches the neutral position.

At the same time, use antitorque pedal pressure to

maintain heading and throttle to maintain r.p.m. With

the helicopter level and the cyclic centered, pause

momentarily to verify everything is correct, and then

gradually raise the collective to complete the liftoff

(frame 3).

After reaching a hover, take care to avoid hitting the

ground with the tail rotor. If an upslope wind exists,

execute a crosswind takeoff and then make a turn into

the wind after clearing the ground with the tail rotor.

COMMON ERRORS

1. Failure to adjust cyclic control to keep the helicopter from sliding downslope.

2. Failure to maintain proper r.p.m.

3. Holding excessive cyclic into the slope as the

downslope skid is raised.

4. Turning the tail of the helicopter into the slope

during takeoff.

CONFINED AREA OPERATIONS

A confined area is an area where the flight of the helicopter is limited in some direction by terrain or the