直升机飞行手册Rotorcraft flying handbook

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your responsibility to ensure the aircraft is in an airworthy condition.

In preparation for flight, the use of a checklist is important

so that no item is overlooked. Follow the manufacturer’s

suggested outline for both the inside and outside inspection. This ensures that all the items the manufacturer

feels are important are checked. Obviously, if there are

other items you feel might need attention, inspect

them as well.

MINIMUM EQUIPMENT LISTS (MELS) AND

OPERATIONS WITH INOPERATIVE

EQUIPMENT

The Code of Federal Regulations (CFRs) requires that

all aircraft instruments and installed equipment be

operative prior to each departure. However, when the

FAA adopted the minimum equipment list (MEL)

concept for 14 CFR part 91 operations, flights were

allowed with inoperative items, as long as the inoperative items were determined to be nonessential for safe

flight. At the same time, it allowed part 91 operators,

without an MEL, to defer repairs on nonessential

equipment within the guidelines of part 91.

There are two primary methods of deferring maintenance

on rotorcraft operating under part 91. They are the deferral provision of 14 CFR part 91, section 91.213(d) and an

FAA-approved MEL.

The deferral provision of section 91.213(d) is widely

used by most pilot/operators. Its popularity is due to

simplicity and minimal paperwork. When inoperative

equipment is found during preflight or prior to departure, the decision should be to cancel the flight, obtain

maintenance prior to flight, or to defer the item or

equipment.

Maintenance deferrals are not used for in-flight discrepancies. The manufacturer's RFM/POH procedures are

to be used in those situations. The discussion that

Minimum Equipment List (MEL)—An inventory of instruments and

equipment that may legally be inoperative, with the specific conditions

under which an aircraft may be flown with such items inoperative.

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follows assumes that the pilot wishes to defer maintenance that would ordinarily be required prior to flight.

Using the deferral provision of section 91.213(d), the

pilot determines whether the inoperative equipment is

required by type design, the CFRs, or ADs. If the inoperative item is not required, and the helicopter can be

safely operated without it, the deferral may be made.

The inoperative item shall be deactivated or removed and

an INOPERATIVE placard placed near the appropriate

switch, control, or indicator. If deactivation or removal

involves maintenance (removal always will), it must be

accomplished by certificated maintenance personnel.

For example, if the position lights (installed equipment)

were discovered to be inoperative prior to a daytime

flight, the pilot would follow the requirements of section 91.213(d).

The deactivation may be a process as simple as the pilot

positioning a circuit breaker to the OFF position, or as

complex as rendering instruments or equipment totally

inoperable. Complex maintenance tasks require a certificated and appropriately rated maintenance person to

perform the deactivation. In all cases, the item or equipment must be placarded INOPERATIVE.

All rotorcraft operated under part 91 are eligible to use

the maintenance deferral provisions of section 91.213(d).

However, once an operator requests an MEL, and a Letter

of Authorization (LOA) is issued by the FAA, then the

use of the MEL becomes mandatory for that helicopter.

All maintenance deferrals must be accomplished in

accordance with the terms and conditions of the MEL and

the operator-generated procedures document.

The use of an MEL for rotorcraft operated under part 91

also allows for the deferral of inoperative items or

equipment. The primary guidance becomes the FAAapproved MEL issued to that specific operator and

N-numbered helicopter.

The FAA has developed master minimum equipment

lists (MMELs) for rotorcraft in current use. Upon written request by a rotorcraft operator, the local FAA Flight

Standards District Office (FSDO) may issue the appropriate make and model MMEL, along with an LOA, and

the preamble. The operator then develops operations

and maintenance (O&M) procedures from the MMEL.

This MMEL with O&M procedures now becomes the

operator's MEL. The MEL, LOA, preamble, and procedures document developed by the operator must be on

board the helicopter when it is operated.

The FAA considers an approved MEL to be a supplemental type certificate (STC) issued to an aircraft by

serial number and registration number. It therefore

becomes the authority to operate that aircraft in a condition other than originally type certificated.

With an approved MEL, if the position lights were discovered inoperative prior to a daytime flight, the pilot

would make an entry in the maintenance record or discrepancy record provided for that purpose. The item is

then either repaired or deferred in accordance with the

MEL. Upon confirming that daytime flight with inoperative position lights is acceptable in accordance with the

provisions of the MEL, the pilot would leave the position

lights switch OFF, open the circuit breaker (or whatever

action is called for in the procedures document), and placard the position light switch as INOPERATIVE.

There are exceptions to the use of the MEL for deferral.

For example, should a component fail that is not listed

in the MEL as deferrable (the rotor tachometer, engine

tachometer, or cyclic trim, for example), then repairs

are required to be performed prior to departure. If maintenance or parts are not readily available at that

location, a special flight permit can be obtained from

the nearest FSDO. This permit allows the helicopter to

be flown to another location for maintenance. This

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allows an aircraft that may not currently meet applicable airworthiness requirements, but is capable of safe

flight, to be operated under the restrictive special terms

and conditions attached to the special flight permit.

Deferral of maintenance is not to be taken lightly, and

due consideration should be given to the effect an inoperative component may have on the operation of a

helicopter, particularly if other items are inoperative.

Further information regarding MELs and operations

with inoperative equipment can be found in AC 91-67,

Minimum Equipment Requirements for General

Aviation Operations Under FAR Part 91.

ENGINE START

AND ROTOR ENGAGEMENT

During the engine start, rotor engagement, and systems

ground check, use the manufacturer’s checklists. If a

problem arises, have it checked before continuing.

Prior to performing these tasks, however, make sure

the area near the helicopter is clear of personnel and

equipment. Helicopters are safe and efficient flying

machines as long as they are operated within the

parameters established by the manufacturer.

ROTOR SAFETY CONSIDERATIONS

The exposed nature of the main and tail rotors deserve

special caution. You must exercise extreme care when

taxiing near hangars or obstructions since the distance

between the rotor blade tips and obstructions is very

difficult to judge. [Figure 9-1] In addition, you cannot

see the tail rotor of some helicopters from the cabin.

Therefore, when hovering backwards or turning in

those helicopters, allow plenty of room for tail rotor

clearance. It is a good practice to glance over your

shoulder to maintain this clearance.

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Another rotor safety consideration is the thrust a helicopter generates. The main rotor system is capable of

blowing sand, dust, snow, ice, and water at high velocities for a significant distance causing injury to nearby

people and damage to buildings, automobiles, and other

aircraft. Loose snow, can severely reduce visibility and

obscure outside visual references. Any airborne debris

near the helicopter can be ingested into the engine air

intake or struck by the main and tail rotor blades.

SAFETY IN AND AROUND HELICOPTERS

People have been injured, some fatally, in helicopter

accidents that would not have occurred had they been

informed of the proper method of boarding or deplaning. A properly briefed passenger should never be

endangered by a spinning rotor. The simplest method

of avoiding accidents of this sort is to stop the rotors

before passengers are boarded or allowed to depart.

Because this action is not always practicable, and to

realize the vast and unique capabilities of the helicopter, it is often necessary to take on passengers or to

deplane them while the engine and rotors are turning.

To avoid accidents, it is essential that all persons associated with helicopter operations, including passengers,

be made aware of all possible hazards and instructed as

to how they can be avoided.

Persons directly involved with boarding or deplaning

passengers, aircraft servicing, rigging, or hooking up

external loads, etc., should be instructed as to their

duties. It would be difficult, if not impossible, to cover

each and every type of operation related to helicopters.

A few of the more obvious and common ones are covered below.

RAMP ATTENDANTS AND AIRCRAFT SERVIC-

ING PERSONNEL—These personnel should be

instructed as to their specific duties, and the proper

method of fulfilling them. In addition, the ramp attendant should be taught to:

1. keep passengers and unauthorized persons out of

the helicopter landing and takeoff area.

2. brief passengers on the best way to approach and

board a helicopter with its rotors turning.

AIRCRAFT SERVICING—The helicopter rotor blades

should be stopped, and both the aircraft and the refueling unit properly grounded prior to any refueling operation. You, as the pilot, should ensure that the proper

grade of fuel and the proper additives, when required,

are being dispensed.

Refueling the aircraft, while the blades are turning,

known as "hot refueling," may be practical for certain

types of operation. However, this can be hazardous if

not properly conducted. Pilots should remain at the

flight controls; and refueling personnel should be

knowledgeable about the proper refueling procedures

and properly briefed for specific helicopter makes and

models.

Refueling units should be positioned to ensure adequate rotor blade clearance. Persons not involved with

the refueling operation should keep clear of the area.

Smoking must be prohibited in and around the aircraft

during all refueling operations.

EXTERNAL-LOAD RIGGERS—Rigger training is

possibly one of the most difficult and continually

changing problems of the helicopter external-load

operator. A poorly rigged cargo net, light standard, or

load pallet could result in a serious and costly accident.

It is imperative that all riggers be thoroughly trained to

meet the needs of each individual external-load operation. Since rigging requirements may vary several

times in a single day, proper training is of the utmost

importance to safe operations.

PILOT AT THE FLIGHT CONTROLS—Many helicopter operators have been lured into a "quick turnaround" ground operation to avoid delays at airport

terminals and to minimize stop/start cycles of the

engine. As part of this quick turnaround, the pilot might

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leave the cockpit with the engine and rotors turning.

Such an operation can be extremely hazardous if a gust

of wind disturbs the rotor disc, or the collective flight

control moves causing lift to be generated by the rotor

system. Either occurrence may cause the helicopter to

roll or pitch, resulting in a rotor blade striking the tailboom or the ground. Good operating procedures dictate

that pilots remain at the flight controls whenever the

engine is running and the rotors are turning.

EXTERNAL-LOAD HOOKUP PERSONNEL—

There are several areas in which these personnel

should be knowledgeable. First, they should know the

lifting capability of the helicopters involved. Since

some operators have helicopter models with almost

Figure 9-1. Exercise extreme caution when hovering near

buildings or other aircraft.

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identical physical characteristics but different lifting

capabilities, this knowledge is essential. For example,

a hookup person may be working with a turbocharged

helicopter on a high altitude project when a non-turbocharged helicopter, which looks exactly the same to

the ground crew, comes to pick up a load. If the

hookup person attaches a load greater than the

non-turbocharged helicopter can handle, a potentially

dangerous situation could exist.

Second, know the pilots. The safest plan is to standardize all pilots in the manner in which sling loads

are picked up and released. Without pilot standardization, the operation could be hazardous. The operator

should standardize the pilots on operations while

personnel are beneath the helicopter.

Third, know the cargo. Many items carried via sling are

very fragile, others can take a beating. The hookup person should always know when a hazardous article is

involved and the nature of the hazard, such as explosives, radioactive materials, and toxic chemicals. In

addition to knowing this, the hookup person should be

familiar with the types of protective gear or clothing

and the actions necessary to protect their own safety

and that of the operation.

Fourth, know appropriate hand signals. When direct

radio communications between ground and flight personnel are not used, the specific meaning of hand

signals should be coordinated prior to operations.

Fifth, know emergency procedures. Ground and flight

personnel should fully agree to and understand the

actions to be taken by all participants in the event of

emergencies. This prior planning is essential to avoid

injuries to all concerned.

PASSENGERS—All persons who board a helicopter

while its rotors are turning should be instructed in the

safest means of doing so. Naturally, if you are at the

controls, you may not be able to conduct a boarding

briefing. Therefore, the individual who arranged for the

passengers' flight or is assigned as the ramp attendant

should accomplish this task. The exact procedures may

vary slightly from one helicopter model to another, but

in general the following should suffice.

When boarding—

1. stay away from the rear of the helicopter.

2. approach or leave the helicopter in a crouching

manner.

3. approach from the side or front, but never out of

the pilot's line of vision.

4. carry tools horizontally, below waist level, never

upright or over the shoulder.

5. hold firmly to hats and loose articles.

6. never reach up or dart after a hat or other object

that might be blown off or away.

7. protect eyes by shielding them with a hand or by

squinting.

8. if suddenly blinded by dust or a blowing object,

stop and crouch lower; or better yet, sit down and

wait for help.

9. never grope or feel your way toward or away

from the helicopter.

Since few helicopters carry cabin attendants, you, as

the pilot, will have to conduct the pre-takeoff and prelanding briefings. The type of operation dictates what

sort of briefing is necessary. All briefings should

include the following:

1. The use and operation of seatbelts for takeoff, en

route, and landing.

2. For overwater flights, the location and use of

flotation gear and other survival equipment that

might be on board. You should also include how

and when to abandon the helicopter should a

ditching be necessary.

3. For flights over rough or isolated terrain, all

occupants should be told where maps and survival gear are located.

4. Passengers should be instructed as to what

actions and precautions to take in the event of an

emergency, such as the body position for best

spinal protection against a high vertical impact

landing (erect with back firmly against the seat

back); and when and how to exit after landing.

Ensure that passengers are aware of the location

of the fire extinguisher and survival equipment.

5. Smoking should not be permitted within 50 feet

of an aircraft on the ground. Smoking could be

permitted, at the discretion of the pilot, except

under the following conditions:

• during all ground operations.

• during, takeoff or landing.

• when carrying flammable or hazardous

materials.

When passengers are approaching or leaving a helicopter that is sitting on a slope with the rotors turning, they

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should approach and depart downhill. This affords the

greatest distance between the rotor blades and the

ground. If this involves walking around the helicopter,

they should always go around the front, never the rear.

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VERTICAL TAKEOFF TO A HOVER

A vertical takeoff, or takeoff to a hover, is a maneuver

in which the helicopter is raised vertically from the surface to the normal hovering altitude (2 to 5 feet) with a

minimum of lateral or longitudinal movement.

TECHNIQUE

Prior to any takeoff or maneuver, you should ensure

that the area is clear of other traffic. Then, head the helicopter into the wind, if possible. Place the cyclic in the

neutral position, with the collective in the full down

position. Increase the throttle smoothly to obtain and

maintain proper r.p.m., then raise the collective. Use

smooth, continuous movement, coordinating the throttle to maintain proper r.p.m. As you increase the collective, the helicopter becomes light on the skids, and

torque tends to cause the nose to swing or yaw to the

right unless sufficient left antitorque pedal is used to

maintain the heading. (On helicopters with a clockwise

main rotor system, the yaw is to the left and right pedal

must be applied.)

As the helicopter becomes light on the skids, make necessary cyclic pitch control adjustments to maintain a

level attitude. When airborne, use the antitorque pedals

to maintain heading and the collective to ensure continuous vertical assent to the normal hovering altitude.

When hovering altitude is reached, use the throttle and

collective to control altitude, and the cyclic to maintain

a stationary hover. Use the antitorque pedals to maintain heading. When a stabilized hover is achieved,

check the engine instruments and note the power

required to hover. You should also note the position of

the cyclic. Cyclic position varies with wind and the

amount and distribution of the load.

Excessive movement of any flight control requires a

change in the other flight controls. For example, if

while hovering, you drift to one side, you naturally

move the cyclic in the opposite direction. When you do

this, part of the vertical thrust is diverted, resulting in a

loss of altitude. To maintain altitude, you must increase

the collective. This increases drag on the blades and

tends to slow them down. To counteract the drag and

maintain r.p.m., you need to increase the throttle.

Increased throttle means increased torque, so you must

add more pedal pressure to maintain the heading. This

can easily lead to overcontrolling the helicopter.

However, as your level of proficiency increases, problems associated with overcontrolling decrease.

COMMON ERRORS

1. Failing to ascend vertically as the helicopter

becomes airborne.

2. Pulling through on the collective after becoming

airborne, causing the helicopter to gain too much

altitude.

3. Overcontrolling the antitorque pedals, which not

only changes the handling of the helicopter, but

also changes the r.p.m.

4. Reducing throttle rapidly in situations where

proper r.p.m. has been exceeded. This usually

results in exaggerated heading changes and loss

of lift, resulting in loss of altitude.

HOVERING

Hovering is a maneuver in which the helicopter is maintained in a nearly motionless flight over a reference

point at a constant altitude and on a constant heading.

The maneuver requires a high degree of concentration

and coordination.

TECHNIQUE

To maintain a hover over a point, you should look for

small changes in the helicopter’s attitude and altitude.

When you note these changes, make the necessary control inputs before the helicopter starts to move from the

point. To detect small variations in altitude or position,

your main area of visual attention needs to be some

distance from the aircraft, using various points on the

helicopter or the tip-path plane as a reference. Looking

too close or looking down leads to overcontrolling.

Obviously, in order to remain over a certain point, you

should know where the point is, but your attention

should not be focused there.

As with a takeoff, you control altitude with the collective and maintain a constant r.p.m. with the throttle.

Use the cyclic to maintain the helicopter’s position and

the pedals to control heading. To maintain the

helicopter in a stabilized hover, make small, smooth,

coordinated corrections. As the desired effect occurs,

remove the correction in order to stop the helicopter’s

movement. For example, if the helicopter begins to

move rearward, you need to apply a small amount of

forward cyclic pressure. However, neutralize this pressure just before the helicopter comes to a stop, or it will

begin to move forward.

After you gain experience, you will develop a certain

“feel” for the helicopter. You will feel and see small

deviations, so you can make the corrections before the

helicopter actually moves. A certain relaxed looseness

develops, and controlling the helicopter becomes second nature, rather than a mechanical response.

COMMON ERRORS

1. Tenseness and slow reactions to movements of

the helicopter.

2. Failure to allow for lag in cyclic and collective

pitch, which leads to overcontrolling.

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3. Confusing attitude changes for altitude changes,

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which result in improper use of the controls.

4. Hovering too high, creating a hazardous flight

condition.

5. Hovering too low, resulting in occasional touchdown.

HOVERING TURN

A hovering turn is a maneuver performed at hovering

altitude in which the nose of the helicopter is rotated

either left or right while maintaining position over a

reference point on the surface. The maneuver requires

the coordination of all flight controls and demands precise control near the surface. You should maintain a

constant altitude, rate of turn, and r.p.m.

TECHNIQUE

Initiate the turn in either direction by applying antitorque pedal pressure toward the desired direction. It

should be noted that during a turn to the left, you need

to add more power because left pedal pressure

increases the pitch angle of the tail rotor, which, in turn,

requires additional power from the engine. A turn to the

right requires less power. (On helicopters with a clockwise rotating main rotor, right pedal increases the pitch

angle and, therefore, requires more power.)

As the turn begins, use the cyclic as necessary (usually

into the wind) to keep the helicopter over the desired

spot. To continue the turn, you need to add more and

more pedal pressure as the helicopter turns to the crosswind position. This is because the wind is striking the

tail surface and tail rotor area, making it more difficult

for the tail to turn into the wind. As pedal pressures

increase due to crosswind forces, you must increase the

cyclic pressure into the wind to maintain position. Use

the collective with the throttle to maintain a constant

altitude and r.p.m. [Figure 9-2]

After the 90° portion of the turn, you need to decrease

pedal pressure slightly to maintain the same rate of

turn. Approaching the 180°, or downwind, portion,

you need to anticipate opposite pedal pressure due to

the tail moving from an upwind position to a downwind position. At this point, the rate of turn has a tendency to increase at a rapid rate due to the

weathervaning tendency of the tail surfaces. Because

of the tailwind condition, you need to hold rearward

cyclic pressure to keep the helicopter over the same

spot.

Because of the helicopter’s tendency to weathervane,

maintaining the same rate of turn from the 180° position actually requires some pedal pressure opposite the

direction of turn. If you do not apply opposite pedal

pressure, the helicopter tends to turn at a faster rate.

The amount of pedal pressure and cyclic deflection

throughout the turn depends on the wind velocity. As

you finish the turn on the upwind heading, apply

opposite pedal pressure to stop the turn. Gradually

apply forward cyclic pressure to keep the helicopter

from drifting.

Cyclic - Forward

Pedal - Some left in

hover, more left to start

turn to left.

Cyclic - Right

Pedal - Most left

pressure in turn.

Cyclic - Rearward

Pedal - Changing from

left to right pressure.

Cyclic - Left

Pedal - Most right pedal

pressure in turn.

Cyclic - Forward

Pedal - Some right to

stop turn, then left to

maintain heading.

Collective - Power

required to hover at

desired height.

Throttle – As necessary

to maintain r.p.m.

Collective -Most power

in turn.

Throttle – As necessary

to maintain r.p.m.

Collective - Power

reducing.

Throttle – As necessary

to maintain r.p.m.

Collective - Least power

in turn.

Throttle – As necessary

to maintain r.p.m.

Collective - Increasing

as left pedal applied.

Throttle – As necessary

to maintain r.p.m.

WIND

Figure 9-2. Left turns in helicopters with a counterclockwise rotating main rotor are more difficult to execute because the tail

rotor demands more power. This requires that you compensate with additional collective pitch and increased throttle. You

might want to refer to this graphic throughout the remainder of the discussion on a hovering turn to the left.

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Control pressures and direction of application change

continuously throughout the turn. The most dramatic

change is the pedal pressure (and corresponding power

requirement) necessary to control the rate of turn as the

helicopter moves through the downwind portion of the

maneuver.

Turns can be made in either direction; however, in a

high wind condition, the tail rotor may not be able to

produce enough thrust, which means you will not be

able to control a turn to the right in a counterclockwise

rotor system. Therefore, if control is ever questionable, you should first attempt to make a 90° turn to the

left. If sufficient tail rotor thrust exists to turn the

helicopter crosswind in a left turn, a right turn can

be successfully controlled. The opposite applies to

helicopters with clockwise rotor systems. In this

case, you should start your turn to the right.

Hovering turns should be avoided in winds strong

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enough to preclude sufficient aft cyclic control to

maintain the helicopter on the selected surface

reference point when headed downwind. Check

the flight manual for the manufacturer’s recommendations for this limitation.

COMMON ERRORS

1. Failing to maintain a slow, constant rate of turn.

2. Failing to maintain position over the reference

point.

3. Failing to maintain r.p.m. within normal range.

4. Failing to maintain constant altitude.

5. Failing to use the antitorque pedals properly.

HOVERING—FORWARD FLIGHT

You normally use forward hovering flight to move a

helicopter to a specific location, and it is usually begun

from a stationary hover. During the maneuver, constant

groundspeed, altitude, and heading should be maintained.

TECHNIQUE

Before starting, pick out two references directly in

front and in line with the helicopter. These reference

points should be kept in line throughout the maneuver.

[Figure 9-3]

Begin the maneuver from a normal hovering altitude by

applying forward pressure on the cyclic. As movement

begins, return the cyclic toward the neutral position to

keep the groundspeed at a slow rate—no faster than a

brisk walk. Throughout the maneuver, maintain a

constant groundspeed and path over the ground with

the cyclic, a constant heading with the antitorque

pedals, altitude with the collective, and the proper

r.p.m. with the throttle.

To stop the forward movement, apply reward cyclic

pressure until the helicopter stops. As forward motion

stops, return the cyclic to the neutral position to prevent rearward movement. Forward movement can also

be stopped by simply applying rearward pressure to

level the helicopter and let it drift to a stop.

COMMON ERRORS

1. Exaggerated movement of the cyclic, resulting in

erratic movement over the surface.

2. Failure to use the antitorque pedals properly,

resulting is excessive heading changes.

3. Failure to maintain desired hovering altitude.

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

HOVERING—SIDEWARD FLIGHT

Sideward hovering flight may be necessary to move

the helicopter to a specific area when conditions make

it impossible to use forward flight. During the maneuver, a constant groundspeed, altitude, and heading

should be maintained.

TECHNIQUE

Before starting sideward hovering flight, make sure the

area you are going to hover into is clear. Then pick two

points of reference in a line in the direction of sideward

hovering flight to help you maintain the proper ground

Reference

Points

Figure 9-3. To maintain a straight ground track, use two reference points in line and at some distance in front of the helicopter.

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track. These reference points should be kept in line

throughout the maneuver. [Figure 9-4]

Begin the maneuver from a normal hovering altitude

by applying cyclic toward the side in which the

movement is desired. As the movement begins, return

the cyclic toward the neutral position to keep the

groundspeed at a slow rate—no faster than a brisk

walk. Throughout the maneuver, maintain a constant

groundspeed and ground track with cyclic. Maintain

heading, which in this maneuver is perpendicular to

the ground track, with the antitorque pedals, and a

constant altitude with the collective. Use the throttle

to maintain the proper operating r.p.m.

To stop the sideward movement, apply cyclic pressure in the direction opposite to that of movement

and hold it until the helicopter stops. As motion

stops, return the cyclic to the neutral position to

prevent movement in the opposite direction.

Applying sufficient opposite cyclic pressure to

level the helicopter may also stop sideward movement. The helicopter then drifts to a stop.

COMMON ERRORS

1. Exaggerated movement of the cyclic, resulting in

overcontrolling and erratic movement over the

surface.

2. Failure to use proper antitorque pedal control,

resulting in excessive heading change.

3. Failure to maintain desired hovering altitude.

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

5. Failure to make sure the area is clear prior to

starting the maneuver.

HOVERING—REARWARD FLIGHT

Rearward hovering flight may be necessary to move the

helicopter to a specific area when the situation is such

that forward or sideward hovering flight cannot be used.

During the maneuver, maintain a constant groundspeed,

altitude, and heading. Due to the limited visibility

behind a helicopter, it is important that you make sure

that the area behind the helicopter is cleared before

beginning the maneuver. Use of ground personnel is recommended.

TECHNIQUE

Before starting rearward hovering flight, pick out two

reference points in front of, and in line with the helicopter just like you would if you were hovering forward. [Figure 9-3] The movement of the helicopter

should be such that these points remain in line.

Begin the maneuver from a normal hovering altitude by

applying rearward pressure on the cyclic. After the

movement has begun, position the cyclic to maintain a

slow groundspeed (no faster than a brisk walk).

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Throughout the maneuver, maintain constant groundspeed and ground track with the cyclic, a constant

heading with the antitorque pedals, constant altitude

with the collective, and the proper r.p.m. with the throttle.

To stop the rearward movement, apply forward cyclic

and hold it until the helicopter stops. As the motion

stops, return the cyclic to the neutral position. Also, as

in the case of forward and sideward hovering flight,

opposite cyclic can be used to level the helicopter and

let it drift to a stop.

COMMON ERRORS

1. Exaggerated movement of the cyclic resulting in

overcontrolling and an uneven movement over

the surface.

2. Failure to use the antitorque pedals properly,

resulting in excessive heading change.

3. Failure to maintain desired hovering altitude.

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

5. Failure to make sure the area is clear prior to

starting the maneuver.

TAXIING

Taxiing refers to operations on, or near the surface of

taxiways or other prescribed routes. In helicopters,

there are three different types of taxiing.

Reference

Points

Figure 9-4. The key to hovering sideward is establishing at

least two reference points that help you maintain a straight

track over the ground while keeping a constant heading.

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HOVER TAXI

A "hover taxi" is used when operating below 25 feet

AGL. [Figure 9-5] Since hover taxi is just like forward,

sideward, or rearward hovering flight, the technique to

perform it will not be presented here.

AIR TAXI

An "air taxi" is preferred when movements require

greater distances within an airport or heliport boundary. [Figure 9-6] In this case, you basically fly to your

new location; however, you are expected to remain

below 100 feet AGL, and to avoid overflight of other

aircraft, vehicles, and personnel.

TECHNIQUE

Before starting, determine the appropriate airspeed and

altitude combination to remain out of the cross-hatched

or shaded areas of the height-velocity diagram.

Additionally, be aware of crosswind conditions that

could lead to loss of tail rotor effectiveness. Pick out

two references directly in front of the helicopter for the

ground path desired. These reference points should be

kept in line throughout the maneuver.

Begin the maneuver from a normal hovering altitude

by applying forward pressure on the cyclic. As movement begins, attain the desired airspeed with the cyclic.

Control the desired altitude with the collective, and

r.p.m. with the throttle. Throughout the maneuver,

maintain a desired groundspeed and ground track with

the cyclic, a constant heading with antitorque pedals,

the desired altitude with the collective, and proper

operating r.p.m. with the throttle.

To stop the forward movement, apply aft cyclic pressure

to reduce forward speed. Simultaneously lower the collective to initiate a descent to hover altitude. As

forward motion stops, return the cyclic to the neutral position to prevent rearward movement. When at the proper

hover altitude, increase the collective as necessary.

COMMON ERRORS

1. Erratic movement of the cyclic, resulting in

improper airspeed control and erratic movement

over the surface.

2. Failure to use antitorque pedals properly, resulting in excessive heading changes.

3. Failure to maintain desired altitude.

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

5. Overflying parked aircraft causing possible damage from rotor downwash.

6. Flying in the cross-hatched or shaded area of the

height-velocity diagram.

7. Flying in a crosswind that could lead to loss of

tail rotor effectiveness.

SURFACE TAXI

A "surface taxi," for those helicopters with wheels, is

used whenever you wish to minimize the effects of

rotor downwash. [Figure 9-7]

TECHNIQUE

The helicopter should be in a stationary position on the

surface with the collective full down and the r.p.m. the

same as that used for a hover. This r.p.m. should be

maintained throughout the maneuver. Then, move the

cyclic slightly forward and apply gradual upward pressure on the collective to move the helicopter forward

Hover Taxi

(25 Feet or Less)

Poor Surface Conditions or Skid Type Helicopters

Figure 9-5. Hover taxi.

Air Taxi

(100 Feet or Less)

Faster Travel

Figure 9-6. Air taxi.

Surface Taxi

Less Rotor Downwash

Figure 9-7. Surface taxi.

9-10

along the surface. Use the antitorque pedals to maintain

heading and the cyclic to maintain ground track. The

collective controls starting, stopping, and speed while

taxiing. The higher the collective pitch, the faster the

taxi speed; however, you should not taxi faster than a

brisk walk. If your helicopter is equipped with brakes,

use them to help you slow down. Do not use the cyclic

to control groundspeed.

During a crosswind taxi, hold the cyclic into the wind a

sufficient amount to eliminate any drifting movement.

COMMON ERRORS

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1. Improper use of cyclic.

2. Failure to use antitorque pedals for heading

control.

3. Improper use of the controls during crosswind

operations.

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

NORMAL TAKEOFF FROM A HOVER

A normal takeoff from a hover is an orderly transition

to forward flight and is executed to increase altitude

safely and expeditiously. During the takeoff, fly a profile that avoids the cross-hatched or shaded areas of the

height-velocity diagram.

TECHNIQUE

Refer to figure 9-8 (position 1). Bring the helicopter to

a hover and make a performance check, which

includes power, balance, and flight controls. The power

check should include an evaluation of the amount of

excess power available; that is, the difference between

the power being used to hover and the power available

at the existing altitude and temperature conditions. The

balance condition of the helicopter is indicated by the

position of the cyclic when maintaining a stationary

hover. Wind will necessitate some cyclic deflection,

but there should not be an extreme deviation from

neutral. Flight controls must move freely, and the helicopter should respond normally. Then visually clear

the area all around.

Start the helicopter moving by smoothly and slowly easing the cyclic forward (position 2). As the helicopter

starts to move forward, increase the collective, as necessary, to prevent the helicopter from sinking and adjust

the throttle to maintain r.p.m. The increase in power

requires an increase in the proper antitorque pedal to

maintain heading. Maintain a straight takeoff path

throughout the takeoff. As you accelerate through effective translational lift (position 3), the helicopter begins

to climb and the nose tends to rise due to increased lift.

At this point adjust the collective to obtain normal climb

power and apply enough forward cyclic to overcome

the tendency of the nose to rise. At position 4, hold an

attitude that allows a smooth acceleration toward climbing airspeed and a commensurate gain in altitude so that

the takeoff profile does not take you through any of the

cross-hatched or shaded areas of the height-velocity

diagram. As airspeed increases (position 5), the streamlining of the fuselage reduces engine torque effect,

requiring a gradual reduction of antitorque pedal

pressure. As the helicopter continues to climb and accelerate to best rate of climb, apply aft cyclic pressure to

raise the nose smoothly to the normal climb attitude.

COMMON ERRORS

1. Failing to use sufficient collective pitch to prevent loss of altitude prior to attaining translational lift.

2. Adding power too rapidly at the beginning of the

transition from hovering to forward flight without

forward cyclic compensation, causing the helicopter

to gain excessive altitude before acquiring airspeed.

Figure 9-8. The helicopter takes several positions during a normal takeoff from a hover. The numbered positions in the text refer

to the numbers in this illustration.

9-11

3. Assuming an extreme nose-down attitude near

the surface in the transition from hovering to

forward flight.

4. Failing to maintain a straight flight path over the

surface (ground track).

5. Failing to maintain proper airspeed during the

climb.

6. Failing to adjust the throttle to maintain proper

r.p.m.

NORMAL TAKEOFF FROM THE

SURFACE

Normal takeoff from the surface is used to move the

helicopter from a position on the surface into effective

translational lift and a normal climb using a minimum

amount of power. If the surface is dusty or covered with

loose snow, this technique provides the most favorable

visibility conditions and reduces the possibility of

debris being ingested by the engine.

TECHNIQUE

Place the helicopter in a stationary position on the surface. Lower the collective to the full down position,

and reduce the r.p.m. below operating r.p.m. Visually

clear the area and select terrain features, or other

objects, to aid in maintaining the desired track during

takeoff and climb out. Increase the throttle to the

proper r.p.m. and raise the collective slowly until the

helicopter is light on the skids. Hesitate momentarily

and adjust the cyclic and antitorque pedals, as necessary, to prevent any surface movement. Continue to

apply upward collective and, as the helicopter breaks

ground, use the cyclic, as necessary, to begin forward

movement as altitude is gained. Continue to accelerate, and as effective translational lift is attained, the

helicopter begins to climb. Adjust attitude and power,

if necessary, to climb in the same manner as a takeoff

from a hover.

COMMOM ERRORS

1. Departing the surface in an attitude that is too

nose-low. This situation requires the use of excessive power to initiate a climb.

2. Using excessive power combined with a level

attitude, which causes a vertical climb.

3. Too abrupt application of the collective when

departing the surface, causing r.p.m. and heading

control errors.

CROSSWIND CONSIDERATIONS

DURING TAKEOFFS

If the takeoff is made during crosswind conditions, the

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helicopter is flown in a slip during the early stages of

the maneuver. [Figure 9-9] The cyclic is held into the

wind a sufficient amount to maintain the desired

ground track for the takeoff. The heading is maintained

with the use of the antitorque pedals. In other words,

the rotor is tilted into the wind so that the sideward

movement of the helicopter is just enough to counteract the crosswind effect. To prevent the nose from

turning in the direction of the rotor tilt, it is necessary

to increase the antitorque pedal pressure on the side

opposite the rotor tilt.

After approximately 50 feet of altitude is gained, make

a coordinated turn into the wind to maintain the desired

ground track. This is called crabbing into the wind. The

stronger the crosswind, the more you have to turn the

helicopter into the wind to maintain the desired ground

track. [Figure 9-10]

Wind

Movement

Helicopter

Side Movement

Figure 9-9. During a slip, the rotor disc is tilted into the wind.

Wind

Movement

Helicopter Ground

Track

Helicopter

Heading

Figure 9-10. To compensate for wind drift at altitude, crab the

helicopter into the wind.

9-12

STRAIGHT-AND-LEVEL FLIGHT

Straight-and-level flight is flight in which a constant

altitude and heading are maintained. The attitude of the

helicopter determines the airspeed and is controlled by

the cyclic. Altitude is primarily controlled by use of the

collective.

TECHNIQUE

To maintain forward flight, the rotor tip-path plane must

be tilted forward to obtain the necessary horizontal

thrust component from the main rotor. This generally

results in a nose-low attitude. The lower the nose, the

greater the power required to maintain altitude, and the

higher the resulting airspeed. Conversely, the greater

the power used, the lower the nose must be to maintain

altitude. [Figure 9-11]

When in straight-and-level flight, any increase in the

collective, while holding airspeed constant, causes the

helicopter to climb. A decrease in the collective, while

holding airspeed constant, causes the helicopter to

descend. A change in the collective requires a coordinated change of the throttle to maintain a constant

r.p.m. Additionally, the antitorque pedals need to be

adjusted to maintain heading and to keep the helicopter

in longitudinal trim.

To increase airspeed in straight-and-level flight, apply

forward pressure on the cyclic and raise the collective

as necessary to maintain altitude. To decrease airspeed,

apply rearward pressure on the cyclic and lower the

collective, as necessary, to maintain altitude.

Although the cyclic is sensitive, there is a slight delay

in control reaction, and it will be necessary to anticipate actual movement of the helicopter. When making

cyclic inputs to control the altitude or airspeed of a helicopter, take care not to overcontrol. If the nose of the

helicopter rises above the level-flight attitude, apply

forward pressure to the cyclic to bring the nose down.

If this correction is held too long, the nose drops too

low. Since the helicopter continues to change attitude

momentarily after the controls reach neutral, return the

cyclic to neutral slightly before the desired attitude is

reached. This principal holds true for any cyclic input.

Since helicopters are inherently unstable, if a gust or

turbulence causes the nose to drop, the nose tends to

continue to drop instead of returning to a straight-andlevel attitude as would a fixed-wing aircraft.

Therefore, you must remain alert and FLY the helicopter at all times.

COMMON ERRORS

1. Failure to properly trim the helicopter, tending to

hold antitorque pedal pressure and opposite

cyclic. This is commonly called cross-controlling.

2. Failure to maintain desired airspeed.

3. Failure to hold proper control position to maintain desired ground track.

TURNS

A turn is a maneuver used to change the heading of the

helicopter. The aerodynamics of a turn were previously

discussed in Chapter 3—Aerodynamics of Flight.

TECHNIQUE

Before beginning any turn, the area in the direction of

the turn must be cleared not only at the helicopter’s altitude, but also above and below. To enter a turn from

straight-and-level flight, apply sideward pressure on

the cyclic in the direction the turn is to be made. This is

the only control movement needed to start the turn. Do

not use the pedals to assist the turn. Use the pedals only

to compensate for torque to keep the helicopter in longitudinal trim. [Figure 9-12]

How fast the helicopter banks depends on how much

lateral cyclic pressure you apply. How far the helicopter banks (the steepness of the bank) depends on how

long you displace the cyclic. After establishing the

proper bank angle, return the cyclic toward the neutral

position. Increase the collective and throttle to main-

Tip-Path Plane

Figure 9-11. You can maintain a straight-and-level attitude by

keeping the tip-path plane parallel to and a constant distance

above or below the natural horizon. For any given airspeed,

this distance remains the same as long as you sit in the same

position in the same type of aircraft.

HCL

Inertia

Figure 9-12. During a level, coordinated turn, the rate of turn

is commensurate with the angle of bank used, and inertia and

horizontal component of lift (HCL) are equal.

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9-13

tain altitude and r.p.m. As the torque increases, increase

the proper antitorque pedal pressure to maintain longitudinal trim. Depending on the degree of bank, additional forward cyclic pressure may be required to

maintain airspeed.

Rolling out of the turn to straight-and-level flight is the

same as the entry into the turn except that pressure on

the cyclic is applied in the opposite direction. Since the

helicopter continues to turn as long as there is any bank,

start the rollout before reaching the desired heading.

The discussion on level turns is equally applicable to

making turns while climbing or descending. The only

difference being that the helicopter is in a climbing or

descending attitude rather than that of level flight. If a

simultaneous entry is desired, merely combine the

techniques of both maneuvers—climb or descent

entry and turn entry. When recovering from a climbing

or descending turn, the desired heading and altitude are

rarely reached at the same time. If the heading is

reached first, stop the turn and maintain the climb or

descent until reaching the desired altitude. On the

other hand, if the altitude is reached first, establish the

level flight attitude and continue the turn to the

desired heading.

SLIPS

A slip occurs when the helicopter slides sideways

toward the center of the turn. [Figure 9-13] It is caused

by an insufficient amount of antitorque pedal in the

direction of the turn, or too much in the direction opposite the turn, in relation to the amount of power used. In

other words, if you hold improper antitorque pedal pressure, which keeps the nose from following the turn, the

helicopter slips sideways toward the center of the turn.

SKIDS

A skid occurs when the helicopter slides sideways

away from the center of the turn. [Figure 9-14] It is

caused by too much antitorque pedal pressure in the

direction of the turn, or by too little in the direction

opposite the turn in relation to the amount of power

used. If the helicopter is forced to turn faster with

increased pedal pressure instead of by increasing the

degree of the bank, it skids sideways away from the

center of the turn instead of flying in its normal curved

pattern.

In summary, a skid occurs when the rate of turn is too

fast for the amount of bank being used, and a slip occurs

when the rate of turn is too slow for the amount of bank

being used.

COMMON ERRORS

1. Using antitorque pedal pressures for turns. This is

usually not necessary for small helicopters.

2. Slipping or skidding in the turn.

NORMAL CLIMB

The entry into a climb from a hover has already been

discussed under “Normal Takeoff from a Hover;” therefore, this discussion is limited to a climb entry from

cruising flight.

TECHNIQUE

To enter a climb from cruising flight, apply aft cyclic to

obtain the approximate climb attitude. Simultaneously

increase the collective and throttle to obtain climb

power and maintain r.p.m. In a counterclockwise rotor

system, increase the left antitorque pedal pressure to

compensate for the increased torque. As the airspeed

approaches normal climb airspeed, adjust the cyclic to

hold this airspeed. Throughout the maneuver, maintain

climb attitude, heading, and airspeed with the cyclic;

climb power and r.p.m. with the collective and throttle;

and longitudinal trim with the antitorque pedals.

To level off from a climb, start adjusting the attitude to the

level flight attitude a few feet prior to reaching the desired

altitude. The amount of lead depends on the rate of climb

at the time of level-off (the higher the rate of climb, the

Slip

Inertia HCL

Figure 9-13. During a slip, the rate of turn is too slow for the

angle of bank used, and the horizontal component of lift

(HCL) exceeds inertia.

Skid

HCL Inertia

Figure 9-14. During a skid, the rate of turn is too fast for the

angle of bank used, and inertia exceeds the horizontal component of lift (HCL).

9-14

more the lead). Generally, the lead is 10 percent of the

climb rate. For example, if your climb rate is 500 feet per

minute, you should lead the level-off by 50 feet.

To begin the level-off, apply forward cyclic to adjust

and maintain a level flight attitude, which is slightly

nose low. You should maintain climb power until the

airspeed approaches the desired cruising airspeed, then

lower the collective to obtain cruising power and adjust

the throttle to obtain and maintain cruising r.p.m.

Throughout the level-off, maintain longitudinal trim

and heading with the antitorque pedals.

COMMON ERRORS

1. Failure to maintain proper power and airspeed.

2. Holding too much or too little antitorque pedal.

3. In the level-off, decreasing power before lowering the nose to cruising attitude.

NORMAL DESCENT

A normal descent is a maneuver in which the helicopter loses altitude at a controlled rate in a controlled

attitude.

TECHNIQUE

To establish a normal descent from straight-and-level

flight at cruising airspeed, lower the collective to obtain

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

increase right antitorque pedal pressure to maintain

heading in a counterclockwise rotor system, or left