直升机飞行手册Rotorcraft flying handbook

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which is then controlled by a small increase in collective pitch control. Avoid a large collective pitch

increase, which results in a rapid decay of rotor r.p.m.,

and leads to “chasing the r.p.m.” Avoid looking straight

down in front of the aircraft. Continually cross-check

attitude, trim, rotor r.p.m., and airspeed.

At approximately 40 to 100 feet above the surface, or

at the altitude recommended by the manufacturer (position 3), begin the flare with aft cyclic control to reduce

forward airspeed and decrease the rate of descent.

Maintain heading with the antitorque pedals. Care must

be taken in the execution of the flare so that the cyclic

control is not moved rearward so abruptly as to cause

the helicopter to climb, nor should it be moved so

slowly as to not arrest the descent, which may allow

the helicopter to settle so rapidly that the tail rotor

strikes the ground. When forward motion decreases to

the desired groundspeed, which is usually the slowest

possible speed (position 4), move the cyclic control

forward to place the helicopter in the proper attitude

for landing.

The altitude at this time should be approximately 8 to

15 feet AGL, depending on the altitude recommended

by the manufacturer. Extreme caution should be used

to avoid an excessive nose high and tail low attitude

below 10 feet. At this point, if a full touchdown landing

is to be made, allow the helicopter to descend vertically

(position 5). Increase collective pitch, as necessary, to

check the descent and cushion the landing. Additional

antitorque pedal is required to maintain heading as collective pitch is raised due to the reduction in rotor

r.p.m. and the resulting reduced effect of the tail rotor.

Touch down in a level flight attitude.

A power recovery can be made during training in lieu

of a full touchdown landing. Refer to the section on

power recoveries for the correct technique.

Figure 11-1. Straight-in autorotation.

11-3

After touchdown and after the helicopter has come to a

complete stop, lower the collective pitch to the fulldown position. Do not try to stop the forward ground

run with aft cyclic, as the main rotor blades can strike

the tail boom. Rather, by lowering the collective

slightly during the ground run, more weight is placed

on the undercarriage, slowing the helicopter.

COMMON ERRORS

1. Failing to use sufficient antitorque pedal when

power is reduced.

2. Lowering the nose too abruptly when power is

reduced, thus placing the helicopter in a dive.

3. Failing to maintain proper rotor r.p.m. during

the descent.

4. Application of up-collective pitch at an excessive

altitude resulting in a hard landing, loss of

heading control, and possible damage to the tail

rotor and to the main rotor blade stops.

5. Failing to level the helicopter.

POWER RECOVERY FROM PRACTICE

AUTOROTATION

A power recovery is used to terminate practice

autorotations at a point prior to actual touchdown.

After the power recovery, a landing can be made or a

go-around initiated.

TECHNIQUE

At approximately 8 to 15 feet above the ground,

depending upon the helicopter being used, begin to

level the helicopter with forward cyclic control. Avoid

excessive nose high, tail low attitude below 10 feet.

Just prior to achieving level attitude, with the nose still

slightly up, coordinate upward collective pitch control

with an increase in the throttle to join the needles at

operating r.p.m. The throttle and collective pitch must

be coordinated properly. If the throttle is increased too

fast or too much, an engine overspeed can occur; if

throttle is increased too slowly or too little in proportion to the increase in collective pitch, a loss of rotor

r.p.m. results. Use sufficient collective pitch to stop the

descent and coordinate proper antitorque pedal

pressure to maintain heading. When a landing is to be

made following the power recovery, bring the helicopter to a hover at normal hovering altitude and then

descend to a landing.

If a go-around is to be made, the cyclic control should

be moved forward to resume forward flight. In transitioning from a practice autorotation to a go-around,

exercise care to avoid an altitude-airspeed combination

that would place the helicopter in an unsafe area of its

height-velocity diagram.

COMMON ERRORS

1. Initiating recovery too late, requiring a rapid application of controls, resulting in overcontrolling.

2. Failing to obtain and maintain a level attitude

near the surface.

3. Failing to coordinate throttle and collective pitch

properly, resulting in either an engine overspeed

or a loss of r.p.m.

4. Failing to coordinate proper antitorque pedal with

the increase in power

AUTOROTATIONS WITH TURNS

A turn, or a series of turns, can be made during an

autorotation in order to land into the wind or avoid

obstacles. The turn is usually made early so that the

remainder of the autorotation is the same as a straight

in autorotation. The most common types are 90° and

180° autorotations. The technique below describes a

180° autorotation.

TECHNIQUE

Establish the aircraft on downwind at recommended

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Several factors affect the rate of descent in autorotation; density altitude, gross weight, rotor r.p.m., and

airspeed. Your primary control of the rate of descent is

airspeed. Higher or lower airspeeds are obtained with

the cyclic pitch control just as in normal flight.

In theory, you have a choice in the angle of descent

varying from a vertical descent to maximum range,

which is the minimum angle of descent. Rate of descent

is high at zero airspeed and decreases to a minimum at

approximately 50 to 60 knots, depending upon the particular helicopter and the factors just mentioned. As the

airspeed increases beyond that which gives minimum

rate of descent, the rate of descent increases again.

When landing from an autorotation, the energy stored

in the rotating blades is used to decrease the rate of

descent and make a soft landing. A greater amount of

rotor energy is required to stop a helicopter with a high

rate of descent than is required to stop a helicopter that

is descending more slowly. Therefore, autorotative

descents at very low or very high airspeeds are more

critical than those performed at the minimum rate of

descent airspeed.

Each type of helicopter has a specific airspeed at which

a power-off glide is most efficient. The best airspeed is

the one which combines the greatest glide range with

the slowest rate of descent. The specific airspeed is

somewhat different for each type of helicopter, yet

certain factors affect all configurations in the same

manner. For specific autorotation airspeeds for a particular helicopter, refer to the FAA-approved rotorcraft

flight manual.

The specific airspeed for autorotations is established

for each type of helicopter on the basis of average

weather and wind conditions and normal loading.

When the helicopter is operated with heavy loads in

high density altitude or gusty wind conditions, best

performance is achieved from a slightly increased airspeed in the descent. For autorotations at low density

altitude and light loading, best performance is achieved

from a slight decrease in normal airspeed. Following

this general procedure of fitting airspeed to existing

conditions, you can achieve approximately the same

glide angle in any set of circumstances and estimate the

touchdown point.

When making turns during an autorotation, generally

use cyclic control only. Use of antitorque pedals to

assist or speed the turn causes loss of airspeed and

downward pitching of the nose. When an autorotation

is initiated, sufficient antitorque pedal pressure should

be used to maintain straight flight and prevent yawing.

This pressure should not be changed to assist the turn.

Use collective pitch control to manage rotor r.p.m. If

rotor r.p.m. builds too high during an autorotation, raise

the collective sufficiently to decrease r.p.m. back to the

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normal operating range. If the r.p.m. begins decreasing,

you have to again lower the collective. Always keep

the rotor r.p.m. within the established range for your

helicopter. During a turn, rotor r.p.m. increases due to

the increased back cyclic control pressure, which

induces a greater airflow through the rotor system. The

r.p.m. builds rapidly and can easily exceed the maximum limit if not controlled by use of collective. The

tighter the turn and the heavier the gross weight, the

higher the r.p.m.

To initiate an autorotation, other than in a low hover,

lower the collective pitch control. This holds true

whether performing a practice autorotation or in the

event of an in-flight engine failure. This reduces the

pitch of the main rotor blades and allows them to

continue turning at normal r.p.m. During practice

autorotations, maintain the r.p.m. in the green arc

with the throttle while lowering collective. Once the

collective is fully lowered, reduce engine r.p.m. by

decreasing the throttle. This causes a split of the

engine and rotor r.p.m. needles.

STRAIGHT-IN AUTOROTATION

A straight-in autorotation implies an autorotation from

altitude with no turns. The speed at touchdown and the

resulting ground run depends on the rate and amount of

flare. The greater the degree of flare and the longer it is

held, the slower the touchdown speed and the shorter

the ground run. The slower the speed desired at touchdown, the more accurate the timing and speed of the

flare must be, especially in helicopters with low inertia

rotor systems.

TECHNIQUE

Refer to figure 11-1 (position 1). From level flight at

the manufacturer’s recommended airspeed, between

500 to 700 feet AGL, and heading into the wind,

smoothly, but firmly lower the collective pitch control

to the full down position, maintaining r.p.m. in the

green arc with throttle. Coordinate the collective movement with proper antitorque pedal for trim, and apply

aft cyclic control to maintain proper airspeed. Once the

collective is fully lowered, decrease throttle to ensure a

clean split of the needles. After splitting the needles,

readjust the throttle to keep engine r.p.m. above

normal idling speed, but not high enough to cause

rejoining of the needles. The manufacturer often

recommends the proper r.p.m.

At position 2, adjust attitude with cyclic control to

obtain the manufacturer’s recommended autorotation

or best gliding speed. Adjust collective pitch control, as

necessary, to maintain rotor r.p.m. in the green arc. Aft

cyclic movements cause an increase in rotor r.p.m.,

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OPERATIONS

A pinnacle is an area from which the surface drops

away steeply on all sides. A ridgeline is a long area

from which the surface drops away steeply on one or

two sides, such as a bluff or precipice. The absence of

obstacles does not necessarily lessen the difficulty of

pinnacle or ridgeline operations. Updrafts, downdrafts,

and turbulence, together with unsuitable terrain in

which to make a forced landing, may still present

extreme hazards.

APPROACH AND LANDING

If you need to climb to a pinnacle or ridgeline, do it on

the upwind side, when practicable, to take advantage of

any updrafts. The approach flight path should be parallel to the ridgeline and into the wind as much as possible. [Figure 10-9]

Load, altitude, wind conditions, and terrain features

determine the angle to use in the final part of an

approach. As a general rule, the greater the winds, the

steeper the approach needs to be to avoid turbulent air

and downdrafts. Groundspeed during the approach is

Altitude over Airspeed—In this type of maneuver, it is more important

to gain altitude than airspeed. However, unless operational considerations dictate otherwise, the crosshatched or shaded areas of the

height/velocity diagram should be avoided.

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more difficult to judge because visual references are

farther away than during approaches over trees or flat

terrain. If a crosswind exists, remain clear of downdrafts on the leeward or downwind side of the

ridgeline. If the wind velocity makes the crosswind

landing hazardous, you may be able to make a low,

coordinated turn into the wind just prior to terminating

the approach. When making an approach to a pinnacle,

avoid leeward turbulence and keep the helicopter

within reach of a forced landing area as long as

possible.

On landing, take advantage of the long axis of the area

when wind conditions permit. Touchdown should be

made in the forward portion of the area. Always perform a stability check, prior to reducing r.p.m., to

ensure the landing gear is on firm terrain that can safely

support the weight of the helicopter.

TAKEOFF

A pinnacle takeoff is an airspeed over altitude maneuver made from the ground or from a hover. Since

pinnacles and ridgelines are generally higher than the

immediate surrounding terrain, gaining airspeed on the

takeoff is more important than gaining altitude. The

higher the airspeed, the more rapid the departure from

slopes of the pinnacle. In addition to covering unfavorable terrain rapidly, a higher airspeed affords a more

favorable glide angle and thus contributes to the

chances of reaching a safe area in the event of a forced

landing. If a suitable forced landing area is not available, a higher airspeed also permits a more effective

flare prior to making an autorotative landing.

On takeoff, as the helicopter moves out of ground

effect, maintain altitude and accelerate to normal climb

airspeed. When normal climb speed is attained, establish a normal climb attitude. Never dive the helicopter

down the slope after clearing the pinnacle.

COMMON ERRORS

1. Failure to perform, or improper performance of, a

high or low reconnaissance.

2. Flying the approach angle at too steep or too shallow an approach for the existing conditions.

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

4. Failure to consider emergency landing areas.

5. Failure to consider how wind and turbulence

could affect the approach and takeoff.

Figure 10-9. When flying an approach to a pinnacle or ridgeline, avoid the areas where downdrafts are present, especially when excess power is limited. If you encounter

downdrafts, it may become necessary to make an immediate

turn away from the pinnacle to avoid being forced into the

rising terrain.

Airspeed over Altitude—This means that in this maneuver, obstacles

are not a factor, and it is more important to gain airspeed than altitude.

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11-1

Today helicopters are quite reliable. However

emergencies do occur, whether a result of mechanical

failure or pilot error. By having a thorough knowledge

of the helicopter and its systems, you will be able to

more readily handle the situation. In addition, by

knowing the conditions that can lead to an

emergency, many potential accidents can be avoided.

AUTOROTATION

In a helicopter, an autorotation is a descending maneuver where the engine is disengaged from the main rotor

system and the rotor blades are driven solely by the

upward flow of air through the rotor. In other words, the

engine is no longer supplying power to the main rotor.

The most common reason for an autorotation is an

engine failure, but autorotations can also be performed

in the event of a complete tail rotor failure, since there

is virtually no torque produced in an autorotation. If

altitude permits, they can also be used to recover from

settling with power. If the engine fails, the freewheeling unit automatically disengages the engine from the

main rotor allowing the main rotor to rotate freely.

Essentially, the freewheeling unit disengages anytime

the engine r.p.m. is less than the rotor r.p.m.

At the instant of engine failure, the main rotor blades

are producing lift and thrust from their angle of attack

and velocity. By immediately lowering collective pitch,

which must be done in case of an engine failure, lift and

drag are reduced, and the helicopter begins an immediate descent, thus producing an upward flow of air

through the rotor system. This upward flow of air

through the rotor provides sufficient thrust to maintain

rotor r.p.m. throughout the descent. Since the tail rotor

is driven by the main rotor transmission during autorotation, heading control is maintained as in normal flight.

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presence of obstructions, natural or manmade. For

example, a clearing in the woods, a city street, a road, a

building roof, etc., can each be regarded as a confined

area. Generally, takeoffs and landings should be made

into the wind to obtain maximum airspeed with minimum groundspeed.

There are several things to consider when operating in

confined areas. One of the most important is maintaining

a clearance between the rotors and obstacles forming the

confined area. The tail rotor deserves special consideration because, in some helicopters, you cannot always see

it from the cabin. This not only applies while making the

approach, but while hovering as well. Another consideration is that wires are especially difficult to see;

however, their supporting devices, such as poles or

towers, serve as an indication of their presence and

approximate height. If any wind is present, you should

also expect some turbulence. [Figure 10-8]

Something else for you to consider is the availability of

forced landing areas during the planned approach. You

should think about the possibility of flying from one

alternate landing area to another throughout the

approach, while avoiding unfavorable areas. Always

leave yourself a way out in case the landing cannot be

completed or a go-around is necessary.

APPROACH

A high reconnaissance should be completed before initiating the confined area approach. Start the approach

phase using the wind and speed to the best possible

advantage. Keep in mind areas suitable for forced landing. It may be necessary to choose between an

Figure 10-7. Slope takeoff.

Wind

Figure 10-8. If the wind velocity is 10 knots or greater, you

should expect updrafts on the windward side and downdrafts

on the lee side of obstacles. You should plan the approach

with these factors in mind, but be ready to alter your plans if

the wind speed or direction changes.

10-8

approach that is crosswind, but over an open area, and

one directly into the wind, but over heavily wooded or

extremely rough terrain where a safe forced landing

would be impossible. If these conditions exist, consider

the possibility of making the initial phase of the

approach crosswind over the open area and then turning into the wind for the final portion of the approach.

Always operate the helicopter as close to its normal

capabilities as possible, taking into consideration the

situation at hand. In all confined area operations, with

the exception of the pinnacle operation, the angle of

descent should be no steeper than necessary to clear

any barrier in the approach path and still land on the

selected spot. The angle of climb on takeoff should be

normal, or not steeper than necessary to clear any barrier. Clearing a barrier by a few feet and maintaining

normal operating r.p.m., with perhaps a reserve of

power, is better than clearing a barrier by a wide margin but with a dangerously low r.p.m. and no power

reserve.

Always make the landing to a specific point and not to

some general area. This point should be located well

forward, away from the approach end of the area. The

more confined the area, the more essential it is that you

land the helicopter precisely at a definite point. Keep

this point in sight during the entire final approach.

When flying a helicopter near obstructions, always

consider the tail rotor. A safe angle of descent over barriers must be established to ensure tail rotor clearance

of all obstructions. After coming to a hover, take care

to avoid turning the tail into obstructions.

TAKEOFF

A confined area takeoff is considered an altitude over

airspeed maneuver. Before takeoff, make a ground

reconnaissance to determine the type of takeoff to be

performed, to determine the point from which the takeoff should be initiated to ensure the maximum amount

of available area, and finally, how to best maneuver the

helicopter from the landing point to the proposed takeoff position.

If wind conditions and available area permit, the helicopter should be brought to a hover, turned around, and

hovered forward from the landing position to the takeoff position. Under certain conditions, sideward flight

to the takeoff position may be necessary. If rearward

flight is required to reach the takeoff position, place

reference markers in front of the helicopter in such a

way that a ground track can be safely followed to the

takeoff position. In addition, the takeoff marker should

be located so that it can be seen without hovering

beyond it.

When planning the takeoff, consider the direction of

the wind, obstructions, and forced landing areas. To

help you fly up and over an obstacle, you should form

an imaginary line from a point on the leading edge of

the helicopter to the highest obstacle to be cleared. Fly

this line of ascent with enough power to clear the

obstacle by a safe distance. After clearing the obstacle,

maintain the power setting and accelerate to the normal

climb speed. Then, reduce power to the normal climb

power setting.

COMMON ERRORS

1. Failure to perform, or improper performance of, a

high or low reconnaissance.

2. Flying the approach angle at too steep or too shallow an approach for the existing conditions.

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

4. Failure to consider emergency landing areas.

5. Failure to select a specific landing spot.

6. Failure to consider how wind and turbulence

could affect the approach.

7. Improper takeoff and climb technique for existing conditions.

PINNACLE AND RIDGELINE

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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

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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).

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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.

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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.

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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.

10-1

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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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.

9-19

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.

9-20

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.