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直升机飞行手册Rotorcraft flying handbook [复制链接]

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109 109 109 109 85 67 48

109 109 109 96 75 57 --

109 109 108 84 66 48 --

109 109 95 74 57 -- --

109 108 84 66 48 -- --

109 109 94 72 49 -- --

09 103 81 59 -- -- --

109 91 70 48 -- -- --

109 80 59 -- -- -- --

109 70 48 -- -- -- --

20

40

60

80

100

0

20

40

60

80

100

MAXIMUM VNE DOORS OFF - 102 MPH IAS

VNE - MPH IAS

GROSS

WEIGHT

MORE

THAN

1,700

LBS

1,700

LBS

OR

LESS

NEVER EXCEED SPEED

Pressure Alt. 1,000 Feet

0 2 4 6 8 10 12 14

110

100

90

80

70

60

50

KIAS

VNE

-20°

C

C

+20° C

+40° C

MAX ALT.

Figure 6-6. Various VNE placards.

ers should describe the systems in a manner that is

understandable to most pilots. For larger, more complex rotorcraft, the manufacturer may assume a higher

degree of knowledge. (For more information on rotorcraft systems, refer to Chapter 5—Helicopter Systems

and Chapter 18—Gyroplane Systems.)

HANDLING, SERVICING, AND

MAINTENANCE

The Handling, Servicing, and Maintenance section

describes the maintenance and inspections recommended by the manufacturer, as well as those required

by the regulations, and Airworthiness Directive (AD)

compliance procedures. There are also suggestions on

how the pilot/operator can ensure that the work is done

properly.

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This section also describes preventative maintenance

that may be accomplished by certificated pilots, as

well as the manufacturer’s recommended ground handling procedures, including considerations for

hangaring, tie down, and general storage procedures

for the rotorcraft.

SUPPLEMENTS

The Supplements Section describes pertinent information necessary to operate optional equipment installed on

the rotorcraft that would not be installed on a standard

aircraft. Some of this information may be supplied by the

aircraft manufacturer, or by the maker of the optional

equipment. The information is then inserted into the

flight manual at the time the equipment is installed.

SAFETY AND OPERATIONAL TIPS

The Safety and Operational Tips is an optional section

that contains a review of information that could

enhance the safety of the operation. Some examples of

the information that might be covered include: physiological factors, general weather information, fuel conservation procedures, external load warnings, low rotor

r.p.m. considerations, and recommendations that if not

adhered to could lead to an emergency.

Airworthiness Directive (AD)—A

regulatory notice that is sent out

by the FAA to the registered owners of aircraft informing them of

the discovery of a condition that

keeps their aircraft from continuing to meet its conditions for airworthiness. Airworthiness

Directives must be complied with

within the required time limit, and

the fact of compliance, the date of

compliance, and the method of

compliance must be recorded in

the aircraft maintenance records.

6-4

These charts, graphs, and tables vary in style but all

contain the same basic information. Some examples

of the performance information that can be found in

most flight manuals include a calibrated versus indicated airspeed conversion graph, hovering ceiling

versus gross weight charts, and a height-velocity diagram. [Figure 6-7] For information on how to use the

charts, graphs, and tables, refer to Chapter 8—

Performance.

WEIGHT AND BALANCE

The Weight and Balance section should contain all the

information required by the FAA that is necessary to

calculate weight and balance. To help you correctly

compute the proper data, most manufacturers include

sample problems. (Weight and balance is further discussed in Chapter 7—Weight and Balance.)

AIRCRAFT AND SYSTEMS

DESCRIPTION

The Aircraft and Systems Description section is an

excellent place to study and familiarize yourself with

all the systems found on your aircraft. The manufactur-

1,500 1,400

0

2,000

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4,000

6,000

8,000

10,000

12,000

1,600 1,700 1,800

PRESSURE ALTITUDE ~ FEET

GROSS WEIGHT ~ LBS

8,000 FT.

DENSITY ALTITUDE

MIXTURE

FULL RICH

OAT120°F

OAT100°F

OAT80°F

OAT60°F

OAT40°F

OAT20°F

OAT0°F

Figure 6-7. One of the performance charts in the Performance

Section is the “In Ground Effect Hover Ceiling versus Gross

Weight” chart. This chart allows you to determine how much

weight you can carry and still operate at a specific pressure

altitude, or if you are carrying a specific weight, what is your

altitude limitation.

7-1

It is vital to comply with weight and balance limits

established for helicopters. Operating above the maximum weight limitation compromises the structural

integrity of the helicopter and adversely affects performance. Balance is also critical because on some

fully loaded helicopters, center of gravity deviations as

small as three inches can dramatically change a helicopter’s handling characteristics. Taking off in a helicopter that is not within the weight and balance

limitations is unsafe.

WEIGHT

When determining if your helicopter is within the

weight limits, you must consider the weight of the basic

helicopter, crew, passengers, cargo, and fuel. Although

the effective weight (load factor) varies during maneuvering flight, this chapter primarily considers the

weight of the loaded helicopter while at rest.

The following terms are used when computing a helicopter’s weight.

BASIC EMPTY WEIGHT—The starting point for

weight computations is the basic empty weight, which

is the weight of the standard helicopter, optional

equipment, unusable fuel, and full operating fluids

including full engine oil. Some helicopters might use

the term “licensed empty weight,” which is nearly the

same as basic empty weight, except that it does not

include full engine oil, just undrainable oil. If you fly a

helicopter that lists a licensed empty weight, be sure to

add the weight of the oil to your computations.

USEFUL LOAD—The difference between the gross

weight and the basic empty weight is referred to as

useful load. It includes the flight crew, usable fuel,

drainable oil, if applicable, and payload.

PAYLOAD—The weight of the passengers, cargo, and

baggage.

GROSS WEIGHT—The sum of the basic empty weight

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and useful load.

MAXIMUM GROSS WEIGHT— The maximum

weight of the helicopter. Most helicopters have an internal maximum gross weight, which refers to the weight

within the helicopter structure and an external maximum

gross weight, which refers to the weight of the helicopter

with an external load.

WEIGHT LIMITATIONS

Weight limitations are necessary to guarantee the structural integrity of the helicopter, as well as enabling you

to predict helicopter performance accurately. Although

aircraft manufacturers build in safety factors, you

should never intentionally exceed the load limits for

which a helicopter is certificated. Operating above a

maximum weight could result in structural deformation

or failure during flight if you encounter excessive load

factors, strong wind gusts, or turbulence. Operating

below a minimum weight could adversely affect the

handling characteristics of the helicopter. During single-pilot operations in some helicopters, you may have

to use a large amount of forward cyclic in order to

maintain a hover. By adding ballast to the helicopter,

the cyclic will be closer to the center, which gives you

a greater range of control motion in every direction.

Additional weight also improves autorotational characteristics since the autorotational descent can be established sooner. In addition, operating below minimum

weight could prevent you from achieving the desirable

rotor r.p.m. during autorotations.

Although a helicopter is certificated for a specified

maximum gross weight, it is not safe to take off with

this load under all conditions. Anything that adversely

affects takeoff, climb, hovering, and landing performance may require off-loading of fuel, passengers, or

baggage to some weight less than the published maximum. Factors which can affect performance include

high altitude, high temperature, and high humidity conditions, which result in a high density altitude.

DETERMINING EMPTY WEIGHT

A helicopter’s weight and balance records contain

essential data, including a complete list of all installed

optional equipment. Use these records to determine the

weight and balance condition of the empty helicopter.

When a helicopter is delivered from the factory, the basic

empty weight, empty weight center of gravity (CG), and

useful load are recorded on a weight and balance data

sheet included in the FAA-Approved Rotocraft Flight

Manual. The basic empty weight can vary even in the

same model of helicopter because of differences in

installed equipment. If the owner or operator of a helicopter has equipment removed, replaced, or additional

equipment installed, these changes must be reflected in

the weight and balance records. In addition, major

7-2

repairs or alterations must be recorded by a certified

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mechanic. When the revised weight and moment are

recorded on a new form, the old record is marked with

the word “superseded” and dated with the effective

date of the new record. This makes it easy to determine

which weight and balance form is the latest version.

You must use the latest weight and balance data for

computing all loading problems.

BALANCE

Helicopter performance is not only affected by gross

weight, but also by the position of that weight. It is

essential to load the aircraft within the allowable centerof-gravity range specified in the rotorcraft flight manual’s weight and balance limitations.

CENTER OF GRAVITY (CG)

The center of gravity is defined as the theoretical point

where all of the aircraft’s weight is considered to be

concentrated. If a helicopter was suspended by a cable

attached to the center-of-gravity point, it would balance

like a teeter-totter. For helicopters with a single main

rotor, the CG is usually close to the main rotor mast.

Improper balance of a helicopter’s load can result in

serious control problems. The allowable range in which

the CG may fall is called the “CG range.” The exact

CG location and range are specified in the rotorcraft

flight manual for each helicopter. In addition to making

a helicopter difficult to control, an out-of-balance loading condition also decreases maneuverability since

cyclic control is less effective in the direction opposite

to the CG location.

Ideally, you should try to perfectly balance a helicopter

so that the fuselage remains horizontal in hovering

flight, with no cyclic pitch control needed except for

wind correction. Since the fuselage acts as a pendulum

suspended from the rotor, changing the center of gravity changes the angle at which the aircraft hangs from

the rotor. When the center of gravity is directly under

the rotor mast, the helicopter hangs horizontal; if the

CG is too far forward of the mast, the helicopter hangs

with its nose tilted down; if the CG is too far aft of the

mast, the nose tilts up. [Figure 7-1]

CG FORWARD OF FORWARD LIMIT

A forward CG may occur when a heavy pilot and passenger take off without baggage or proper ballast

located aft of the rotor mast. This situation becomes

worse if the fuel tanks are located aft of the rotor mast

because as fuel burns the weight located aft of the rotor

mast becomes less.

You can recognize this condition when coming to a

hover following a vertical takeoff. The helicopter will

have a nose-low attitude, and you will need excessive

rearward displacement of the cyclic control to maintain

a hover in a no-wind condition. You should not continue

flight in this condition, since you could rapidly run out

of rearward cyclic control as you consume fuel. You also

may find it impossible to decelerate sufficiently to bring

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the helicopter to a stop. In the event of engine failure and

the resulting autorotation, you may not have enough

cyclic control to flare properly for the landing.

A forward CG will not be as obvious when hovering into

a strong wind, since less rearward cyclic displacement is

required than when hovering with no wind. When determining whether a critical balance condition exists, it is

essential to consider the wind velocity and its relation to

the rearward displacement of the cyclic control.

CG AFT OF AFT LIMIT

Without proper ballast in the cockpit, exceeding the aft

CG may occur when:

• A lightweight pilot takes off solo with a full load

of fuel located aft of the rotor mast.

• A lightweight pilot takes off with maximum baggage allowed in a baggage compartment located

aft of the rotor mast.

• A lightweight pilot takes off with a combination

of baggage and substantial fuel where both are aft

of the rotor mast.

You can recognize the aft CG condition when coming

to a hover following a vertical takeoff. The helicopter

will have a tail-low attitude, and you will need exces-

Forward CG

CG Directly Under The Rotor Mast Aft CG

Figure 7-1. The location of the center of gravity strongly influences how the helicopter handles.

7-3

sive forward displacement of cyclic control to maintain a hover in a no-wind condition. If there is a wind,

you need even greater forward cyclic.

If flight is continued in this condition, you may find it

impossible to fly in the upper allowable airspeed range

due to inadequate forward cyclic authority to maintain a

nose-low attitude. In addition, with an extreme aft CG,

gusty or rough air could accelerate the helicopter to a

speed faster than that produced with full forward cyclic

control. In this case, dissymmetry of lift and blade flapping could cause the rotor disc to tilt aft. With full forward cyclic control already applied, you might not be

able to lower the rotor disc, resulting in possible loss of

control, or the rotor blades striking the tailboom.

LATERAL BALANCE

For most helicopters, it is usually not necessary to

determine the lateral CG for normal flight instruction

and passenger flights. This is because helicopter cabins are relatively narrow and most optional equipment is located near the center line. However, some

helicopter manuals specify the seat from which you

must conduct solo flight. In addition, if there is an

unusual situation, such as a heavy pilot and a full

load of fuel on one side of the helicopter, which could

affect the lateral CG, its position should be checked

against the CG envelope. If carrying external loads in

a position that requires large lateral cyclic control

displacement to maintain level flight, fore and aft

cyclic effectiveness could be dramatically limited.

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WEIGHT AND BALANCE

CALCULATIONS

When determining whether your helicopter is properly

loaded, you must answer two questions:

1. Is the gross weight less than or equal to the maximum allowable gross weight?

2. Is the center of gravity within the allowable CG

range, and will it stay within the allowable range

as fuel is burned off?

To answer the first question, just add the weight of the

items comprising the useful load (pilot, passengers,

fuel, oil, if applicable, cargo, and baggage) to the basic

empty weight of the helicopter. Check that the total weight

does not exceed the maximum allowable gross weight.

To answer the second question, you need to use CG or

moment information from loading charts, tables, or graphs

in the rotorcraft flight manual. Then using one of the

methods described below, calculate the loaded moment

and/or loaded CG and verify that it falls within the allowable CG range shown in the rotorcraft flight manual.

It is important to note that any weight and balance computation is only as accurate as the information provided.

Therefore, you should ask passengers what they weigh

and add a few pounds to cover the additional weight of

clothing, especially during the winter months. The baggage weight should be determined by the use of a scale, if

practical. If a scale is not available, be conservative and

overestimate the weight. Figure 7-2 indicates the standard weights for specific operating fluids.

The following terms are used when computing a helicopter’s balance.

REFERENCE DATUM—Balance is determined by the

location of the CG, which is usually described as a

given number of inches from the reference datum. The

horizontal reference datum is an imaginary vertical

plane or point, arbitrarily fixed somewhere along the

longitudinal axis of the helicopter, from which all horizontal distances are measured for weight and balance

purposes. There is no fixed rule for its location. It may

be located at the rotor mast, the nose of the helicopter,

or even at a point in space ahead of the helicopter.

[Figure 7-3]

Aviation Gasoline (AVGAS) . . . . . . . . . . . . . . . . . . .6 lbs. / gal.

Jet Fuel (JP-4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5 lbs. / gal.

Jet Fuel (JP-5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.8 lbs. / gal.

Reciprocating Engine Oil . . . . . . . . . . . . . . . . . . 7.5 lbs. / gal.*

Turbine Engine Oil . . Varies between 7.5 and 8.5 lbs. / gal.*

Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8.35 lbs. / gal.

* Oil weight is given in pounds per gallon while oil capacity

is usually given in quarts; therefore, you must convert the

amount of oil to gallons before calculating its weight.

Figure 7-2. When making weight and balance computations,

always use actual weights if they are available, especially if

the helicopter is loaded near the weight and balance limits.

Datum

+ –

Figure 7-3. While the horizontal reference datum can be anywhere the manufacturer chooses, most small training helicopters have the horizontal reference datum 100 inches

forward of the main rotor shaft centerline. This is to keep all

the computed values positive.

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7-4

The lateral reference datum, is usually located at the

center of the helicopter. The location of the reference

datums is established by the manufacturer and is

defined in the rotorcraft flight manual. [Figure 7-4]

ARM—The horizontal distance from the datum to any

component of the helicopter or to any object located

within the helicopter is called the arm. Another term

that can be used interchangeably with arm is station.

If the component or object is located to the rear of the

datum, it is measured as a positive number and usually is referred to as inches aft of the datum.

Conversely, if the component or object is located forward of the datum, it is indicated as a negative number and is usually referred to as inches forward of the

datum.

MOMENT—If the weight of an object is multiplied by

its arm, the result is known as its moment. You may

think of moment as a force that results from an object’s

weight acting at a distance. Moment is also referred to

as the tendency of an object to rotate or pivot about a

point. The farther an object is from a pivotal point, the

greater its force.

CENTER OF GRAVITY COMPUTATION—By totaling the

weights and moments of all components and objects carried, you can determine the point where a loaded helicopter would balance. This point is known as the center

of gravity.

WEIGHT AND BALANCE METHODS

Since weight and balance is so critical to the safe operation of a helicopter, it is important to know how to

check this condition for each loading arrangement.

Most helicopter manufacturers use one of two methods, or a combination of the methods, to check weight

and balance conditions.

COMPUTATIONAL METHOD

With the computational method, you use simple mathematics to solve weight and balance problems. The first

step is to look up the basic empty weight and total

moment for the particular helicopter you fly. If the center of gravity is given, it should also be noted. The

empty weight CG can be considered the arm of the

empty helicopter. This should be the first item recorded

on the weight and balance form. [Figure 7-5]

Next, the weights of the oil, if required, pilot, passengers, baggage, and fuel are recorded. Use care in

recording the weight of each passenger and baggage.

Recording each weight in its proper location is

extremely important to the accurate calculation of a

CG. Once you have recorded all of the weights, add

them together to determine the total weight of the

loaded helicopter.

Now, check to see that the total weight does not exceed

the maximum allowable weight under existing conditions. In this case, the total weight of the helicopter is

under the maximum gross weight of 3,200 pounds.

Figure 7-4. The lateral reference datum is located longitudinally through the center of the helicopter; therefore, there are

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positive and negative values.

Weight Arm Moment

(pounds) (inches) (lb/inches)

Basic Empty Weight

Oil

Pilot

Forward Passenger

Passengers Aft

Baggage

Fuel

Total

CG

1,700

12

190

170

510

40

553

3,175

116.5

179.0

65.0

65.0

104

148

120

109.9

198,050

2,148

12,350

11,050

53,040

5,920

66,360

348,918

Max Gross Weight = 3,200 lbs. CG Range 106.0 – 114.2 in.

Figure 7-5. In this example, the helicopter’s weight of 1,700

pounds is recorded in the first column, its CG or arm of 116.5

inches in the second, and its moment of 198,050 poundinches in the last. Notice that the weight of the helicopter,

multiplied by its CG, equals its moment.

Lateral

Datum

+ –

+ –

Front View

Top View

7-5

Once you are satisfied that the total weight is within

prescribed limits, multiply each individual weight by

its associated arm to determine its moment. Then, add

the moments together to arrive at the total moment for

the helicopter. Your final computation is to find the

center of gravity of the loaded helicopter by dividing

the total moment by the total weight.

After determining the helicopter’s weight and center

of gravity location, you need to determine if the CG

is within acceptable limits. In this example, the

allowable range is between 106.0 inches and 114.2

inches. Therefore, the CG location is within the

acceptable range. If the CG falls outside the acceptable limits, you will have to adjust the loading of the

helicopter.

LOADING CHART METHOD

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You can determine if a helicopter is within weight and

CG limits using a loading chart similar to the one in

figure 7-6. To use this chart, first subtotal the empty

weight, pilot, and passengers. This is the weight at

which you enter the chart on the left. The next step is to

follow the upsloping lines for baggage and then for fuel

to arrive at your final weight and CG. Any value on or

inside the envelope is within the range.

SAMPLE PROBLEM 1

Determine if the gross weight and center of gravity are

within allowable limits under the following loading

conditions for a helicopter based on the loading chart

in figure 7-6.

To use the loading chart for the helicopter in this example, you must add up the items in a certain order. The

maximum allowable gross weight is 1,600 pounds.

ITEM POUNDS

Basic empty weight 1,040

Pilot 135

Passenger 200

Subtotal 1,375 (point A)

Baggage compartment load 25

Subtotal 1,400 (point B)

Fuel load (30 gallons) 180

Total weight 1,580 (point C)

1. Follow the green arrows in figure 7-6. Enter the

graph on the left side at 1,375 lb., the subtotal of

the empty weight and the passenger weight.

Move right to the yellow line. (point A)

2. Move up and to the right, parallel to the baggage

compartment loading lines to 1,400 lb. (Point B)

3. Continue up and to the right, this time parallel to

the fuel loading lines, to the total weight of 1,580

lb. (Point C).

Point C is within allowable weight and CG limits.

SAMPLE PROBLEM 2

Assume that the pilot in sample problem 1 discharges

the passenger after using only 20 pounds of fuel.

ITEM POUNDS

Basic empty weight 1,040

Pilot 135

Subtotal 1,175 (point D)

Baggage compartment load 25

Subtotal 1,200 (point E)

Fuel load 160

Total weight 1,360 (point F)

Follow the blue arrows in figure 7-6, starting at 1,175

lb. on the left side of the graph, then to point D, E, and

F. Although the total weight of the helicopter is well

below the maximum allowable gross weight, point F

falls outside the aft allowable CG limit.

As you can see, it is important to reevaluate the balance

in a helicopter whenever you change the loading. Unlike

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