Content .. 6 7 8 9 ..

OPERATOR’S MANUAL FOR ARMY CH-47D HELICOPTER (EIC: RCD, 2003) - page 8

TM 1-1520-240-10

6-6-62. Load Dumping From Ramp.

binations of weight and balance matching the mission

requirements. Table 6-6-1 lists the weights, ARM and

moments of ERFS II and FARE kit installations.

CAUTION

Damage to the helicopter or load could

occur when load dumping from the ramp.

WARNING

Make sure taxi surface is level and free of

obstacles.

Some combinations of ERFS II configura-

tion and auxiliary fuel load will cause the

Dumping from the ramp is not a routine operation, but

helicopter to exceed weight and balance

under urgent conditions can be accomplished as follows:

limits. It is the responsibility of the flight

crew to ensure the helicopter center of

a. Helicopter at full stop.

gravity remains within operating limits at

b. Remove ramp extensions and rollers if installed.

take-off and landing.

c. Load released, but under control and moved to

Standard configuration for the ERFS II consists of three

aft cabin ramp with ramp slightly in up position.

tank assemblies, fuel transfer hose assembly, fuel con-

trol panel, restraint system, FARE kit, and unusable fuel,

with Tank 1 C.G. at 250 inches, Tank 2 C.G. at 330 inch-

WARNING

es, Tank 3 C.G. at 410 inches, and FARE kit C.G. at 464

inches.

Crew members must remain clear of load.

d. Helicopter taxis forward at approximately 5 knots

6-6-64. Restraint System Limits.

ground speed. When 5 knots is reached, the ramp should

be lowered and load pushed out the ramp of the helicop-

The limitations of the restraint system are 8 G’s forward.

ter.

3 G’s aft, 8 G’s vertical, and 8 G’s lateral, measured with

each tank one half full of fuel.

e. Repeat as required.

6-6-65. Breaking Loads of Self Sealing Breakaway

6-6-63. Extended Range Fuel System (ERFS), ERFS

Valves.

II and FARE Kit Weight and Balance Data.

The breaking loads of the self sealing breakaway valves

Refer to figure 6-1-1, table 6-6-3 and 6-6-2.

utilized in the ERFS II fuel and vent assemblies are:

The operator, upon configuration of ERFS II and FARE

moment bending 750 lbs ("150 lbs) at 7 inches, and

kit, must compute various fuel amounts to calculate com-

tension 4,300 lbs.

Table 6-6-1. Extended Range Fuel System (ERFS) Weight and Balance Data

Configuration

Weights/Balance

Station

Moments/1000

Fuel Tank 1

511.3

230.0

117.6

Fuel Tank 2

511.3

290.0

148.3

Fuel Tank 3

511.3

350.0

178.9

Fuel Tank 4

511.3

410.0

209.6

FMCP

190

9.1

Vent Lines

320

4.8

Pump Discharge Lines

290

5.8

Feed Lines/Manifold

290

20.3

Forward Area Refueling

800

502

401.6

Equipment (FARE)

(2 Pumps, 2 Filters, and 2 Fuel Cans)

HICKS

878

379.9

333.5

3/463L Pallets (290 lbs ea.)

870

323

281.0

6-6-25

TM 1-1520-240-10

Table 6-6-2. Extended Range Fuel System II (ERFS II) Weight and Balance Data

Item

Weight (LBS)

Station (ARM)

Moment/1000

Single-point Refuel Hose

23.0

240.

5.5

Total Weight and Moment

23.0

5.5

ERFS II Tank 1 (Empty)

607.0

250.0

151.8

Unusable Fuel (5.5 gal JP-8)

36.0

250.0

9.0

Fuel Control Panel (FCP)

20.0

217.0

4.3

Vent Hose

10.0

235.0

2.4

Elect Harness, Hel to FCP

7.0

235.0

1.6

Elect Harness, FCP to Tank

8.0

238.0

1.9

Wiring Harness, Fuel Qty

8.0

240.0

1.9

Restraint Assembly

81.0

250.0

20.3

Total Weight and Moment

777.0

193.2

ERFS II Tank 2 (Empty)

607.0

330.0

200.3

Unusable Fuel (5.5 gal JP-8)

36.0

330.0

11.9

Elect Harness, FCP to Tank

8.0

278.0

2.2

Fuel Hose

15.0

285.0

4.3

Vent Hose

10.0

305.0

3.1

Restraint Assembly

81.0

330.0

26.7

Total Weight and Moment

757.0

248.5

ERFS II Tank 3 (Empty)

607.0

410.0

248.9

Unusable Fuel (5.5 gal JP-8)

36.0

410.0

14.8

Elect Harness, FCP to Tank

8.0

319.0

2.6

Fuel Hose

15.0

375.0

5.6

Vent Hose

10.0

385.0

3.9

Restraint Assembly

81.0

410.0

33.2

Total Weight and Moment

757.0

309.0

Fuel Hose, Main to ERFS II

29.0

363.0

10.5

Fuel Hose, Fuel Transfer

13.0

400.0

5.2

Total Weight and Moment

42.0

15.7

FARE Kit (Pump Module, hose, couplings, filters,

563.0

464.0

261.2

meters, and nozzles)

Total Weight and Moment

563.0

261.2

TOTAL ERFS II (including FARE) Weight and

2,919.0

1033.1

Moment

6-6-26

TM 1-1520-240-10

Table 6-6-3. Loading Sequence Configuration

463L Pallet Configurations

Configuration

Component

Comment

Load

Outboard Rollers

Down

Warehouse Guides

Down

Ramp Extension/Ramp Jacks

In Place as Required

Ramp Extension/Ramp Extension

In Place as Required

Rollers

Locks

Up (Unlock)

Retractable Flange

Rotate Outboard (Unlock)

5k/10k Rings

Down (Stowed Position)

Restraint

Outboard Rollers

Warehouse Guides

Ramp Extension/Ramp Jacks

Ramp Extension/Ramp Extension

Rollers

Locks

Down (Locked)

Retractable Flange

Rotate Inboard (Locked)

5k/10k Rings

Flight

Outboard Rollers

Warehouse Guides

Ramp Extension/Ramp Jacks

Stow in Helicopter

Ramp Extension/Ramp Extension

Rotate Ramp Extension on Ramp,

Rollers

Rollers on Underside (Stowed Position)

Locks

Retractable Flange

5k/10k Rings

Unload

Outboard Rollers

Warehouse Guides

Ramp Extension/Ramp Jacks

In Place as Required

Ramp Extension/Ramp Extension

In Place as Required

Rollers

Locks

Up (Unlock)

Retractable Flange

Rotate Outboard (Unlock)

5k/10k Rings

Warehouse Pallet Configuration

Configuration

Component

Comment

Load

Outboard Rollers

Down

Warehouse Guides

6-6-27

TM 1-1520-240-10

Table 6-6-3. Loading Sequence Configuration (Continued)

Warehouse Pallet Configuration

Configuration

Component

Comment

Ramp Extension/Ramp Jacks

In Place as Required

Ramp Extension/Ramp Extension

In Place as Required

Rollers

Locks

Down (Unlocked)

Retractable Flange

Rotate Outboard (Unlock)

5k/10k Rings

Restraint

Outboard Rollers

Warehouse Guides

Ramp Extension/Ramp Jacks

Ramp Extension/Ramp Extensions

Rollers

Locks

Retractable Flange

5k/10k Rings

Using Straps, Secure cargo to 5/10k

Rings

Flight

Outboard Rollers

Warehouse Guides

Ramp Extension/Ramp Jacks

Stow in Aircraft

Ramp Extension/Ramp Extensions

Rotate Ramp Extension on Ramp,

Rollers

Rollers on Underside

Locks

Retractable Flange

5k/10k Rings

Unload

Outboard Rollers

Warehouse Guides

Ramp Extension/Ramp Jacks

In Place as Required

Ramp Extension/Ramp Extension

In Place as Required

Rollers

Locks

Up (Unlock)

Retractable Flange

Rotate Outboard (Unlock)

5k/10k Rings

Wheeled Vehicle Configurations

Configuration

Component

Comment

Load

Outboard Rollers*

Up-Straps on Cabin, Ramp Up

Warehouse Guides

Down

Ramp Extension/Ramp Jacks

No Ramp Extension Jacks, No Ramp

Jack (Ramp on Ground)

Ramp Extension/Ramp Extension

Ramp Extension on Ground, No

6-6-28

TM 1-1520-240-10

Table 6-6-3. Loading Sequence Configuration (Continued)

Wheeled Vehicle Configurations

Configuration

Component

Comment

Rollers

Locks

Down (Locked)

Retractable Flange

Rotate Outboard (Unlock)

5k/10k Rings

Restraint

Outboard Rollers

Warehouse Guides

Ramp Extension/Ramp Jacks

Ramp Extension/Ramp Extension

Rollers

Locks

Retractable Flange

5k/10k Rings

Using Straps and/or Chains, Secure

Cargo to 5k/10k Rings

Flight

Outboard Rollers

Warehouse Guides

Ramp Extension/Ramp Jacks

Stow in Helicopter

Ramp Extension/Ramp Extension

Rotate Ramp Extension on Ramp,

Rollers

Rollers on Underside

Locks

Retractable Flange

5k/10k Rings

Unload

Outboard Rollers

Warehouse Guides

Ramp Extension/Ramp Jacks

Ramp on Ground

Ramp Extension/Ramp Extension

Ramp Extension on Ground

Rollers

Locks

Retractable Flange

* Maximum available width with out-

board rollers in stowed position is 85

inches lateral width.

6-6-29

TM 1-1520-240-10

Figure 6-6-14. Loading With Ramp Down (Forklift Loading)

6-6-30

TM 1-1520-240-10

Figure 6-6-15. Loading With Ramp In Level Position

6-6-31

TM 1-1520-240-10

Figure 6-6-16. Loading Clearances

6-6-32

TM 1-1520-240-10

SECTION VII. LOADING LIMITS

6-7-1. General

The loading limits are depicted in figure 6-7-1. Using

loading techniques specified in this chapter, it would be

difficult to exceed these limits.

6-7-1

TM 1-1520-240-10

Figure 6-7-1. C.G. Limits Chart

6-7-2

TM 1-1520-240-10

CHAPTER 7

712 PERFORMANCE DATA

SECTION I. INTRODUCTION

7-1-1. Purpose.

limits with an operating cruise guide indicator (CGI).

Airspeed limits with the CGI inoperative are in Chapter 5.

The purpose of this chapter is to provide the best available

If limits are exceeded, minimize the degree and time.

performance data for the CH-47D helicopter. Regular use

of this information will enable you to receive maximum safe

7-1-4. Use of Charts.

utilization from the aircraft. Although maximum perfor-

mance is not always required, regular use of this chapter

a. Chart Explanation. The first page of each section

is recommended for the following reasons.

describes the chart(s) and explains its use.

a. Knowledge of your performance margin will allow

b. The primary use of each chart is given in an exam-

you to make better decisions when unexpected

ple and a guideline is provided to help you follow the

conditions or alternate missions are encountered.

route through the chart. The use of a straight edge (ruler

or page edge) and a hard fine point pencil is recom-

b. Situations requiring maximum performance will be

mended to avoid cumulative errors. The majority of the

more readily recognized.

charts provide a standard pattern for use as follows:

enter first variable on the top left scale, move right to the

c. Familiarity with the data will allow performance to

second variable, deflect down at right angles to the third

be computed more easily and quickly.

variable, deflect left at right angles to the fourth variable,

d. Experience will be gained in accurately estimating

deflect down, etc. until the final variable is read out at the

the effects of variables for which data are not presented.

final scale. In addition to the primary use, other uses of

each chart are explained in the text accompanying each

set of performance charts.

7-1-2. General Data.

NOTE

The data presented covers the maximum range of condi-

tions and performance that can reasonably be expected.

An example of an auxiliary use of the charts

In each area of performance, the effects of altitude, tem-

referenced above is as follows: Although the

perature, gross weight (GW), and other parameters re-

hover chart is primarily arranged to find

lating to that phase of flight are presented. In addition to

torque required to hover, by entering torque

the presented data, your judgement and experience will

available as torque required, maximum wheel

be necessary to accurately obtain performance under a

height for hover can also be found. In general,

given set of circumstances. The conditions for the data

any single variable can be found if all others

are listed under the title of each chart. The effects of

are known. Also, the tradeoffs between vari-

different conditions are discussed in the text accompany-

ables can be found. For example, at a give

ing each phase of performance. Where practical, data is

pressure altitude (PA), you can find the maxi-

presented at conservative conditions. However, NO

mum GW capability as free air temperature

GENERAL CONSERVATISM HAS BEEN APPLIED. All

(FAT) changes.

performance data presented is within the applicable lim-

c. Dashed Line Data. Data beyond conditions for

its of the aircraft.

which tests were conducted, or for which estimates are

used, are shown as dashed lines.

CAUTION

7-1-5. Data Basis.

Exceeding operating limits can cause per-

manent damage to critical components.

The type of data used is indicated at the bottom of each

Over limit operation can decrease perfor-

performance chart under DATA BASIS. The applicable

mance, cause immediate failure, or failure

report and date of the data are also given. The data

on a subsequent flight.

provided generally is based on one of the following cate-

gories.

7-1-3. Limits.

a. Flight Test Data. Data obtained by flight test of the

Applicable limit lines are shown on the charts. The

aircraft by experienced flight test personnel at precise

dashed lines on the cruise charts are estimated airspeed

conditions using sensitive calibrated instruments.

7-1-1

TM 1-1520-240-10

b. Calculated Data. Data based on tests, but not on

7-1-8. ERFS II Performance Data.

flight test of the complete aircraft.

Use of the performance data will enable the operator to

receive the maximum safe utilization of the ERFS II and

c. Estimated Data. Data based on estimates using

FARE kit.

aerodynamic theory or other means but not verified by

flight test.

7-1-9. ERFS II Tank Capacity.

The capacity of the ERFS II tank using pressure refueling

7-1-6. Specific Conditions.

is 805.5 US gallons. If filled using gravity refueling, the

capacity is 825.5 US gallons (In both cases 5.5 GALS will

The data presented is accurate only for specific condi-

be unusable).

tions listed under the title of each chart. Variables for

which data are not presented, but which may affect that

7-1-10. Amount of Unusable Fuel.

phase of performance, are discussed in the text. Where

data is available or reasonable estimates can be made,

7-1-11. Fuel Transfer Rate.

the amount that each variable affects performance will be

given.

The amount of unusable fuel in each of the ERFS II tanks

is 5.5 US gallons of JP-8.

7-1-7. General Conditions.

The rate at which fuel is transferred from the ERFS II

tanks to the helicopter main tanks is 23 GPM.

In addition to the specific conditions, the following gener-

al conditions are applicable to the performance data.

7-1-12. FARE Transfer Rate.

The FARE kit pump is rated at 120 GPM. However, the

a. Rigging. All airframe and engine controls are

configuration of the FARE fuel transfer hose assembly

assumed to be rigged within allowable tolerances.

affects this transfer rate. Pressure losses across cou-

b. Pilot Technique. Normal pilot technique is

plings, filters, and nozzles reduce the flow rate below the

assumed.

rated value. The rate at which fuel is transferred from the

ERFS II tanks using the FARE pump and standard con-

c. Aircraft Variation. Variations in performance

figuration of the FARE fuel transfer hose assemble is 84

between individual aircraft are known to exist: however,

to 88 GPM.

they are considered to be small and cannot be accounted

7-1-13. Performance Discrepancies.

for individually.

Regular use of this chapter will allow you to monitor in-

d. Instrument Variations. The data shown in the

struments and other aircraft systems for malfunction by

performance charts does not allow for instrument

comparing actual performance with planned perfor-

inaccuracies or malfunctions.

mance. Knowledge will also be gained concerning the

effects of variables for which data are not provided,

e. Airspeed Calibrations. The airspeed calibration

thereby increasing the accuracy of performance predica-

chart presents the difference between indicated airspeed

tions.

(IAS), and calibrated airspeeds (CAS) for different flight

conditions.

7-1-14. Definitions of Abbreviations.

f. Except as noted, all data is for clean configuration

Capitalization and punctuation of abbreviations varies,

(all doors installed, without armament).

depending upon the context in which they are used. In

general, full capital letter abbreviations are used in text

g. Types of Fuel. All flight performance data is based

material, charts and illustrations. Periods do not usually

on JP-5 fuel. The change in fuel flow and torque

follow abbreviations; however, periods are used with ab-

available, when using JP-4, JP-8, Aviation gasoline or

breviations that could be mistaken for whole words if the

any other approved fuels, is insignificant.

period were omitted.

7-1-2

TM 1-1520-240-10

Figure 7-1-1. Temperature Conversion Chart

7-1-3/(7-1-4 blank)

TM 1-1520-240-10

SECTION II. EMERGENCY TORQUE AVAILABLE

7-2-1. Emergency Torque Available.

to know PA, and FAT. Enter the left side of the chart at

known temperature, move right to known pressure alti-

Single engine emergency torque available may be ob-

tude, then down to read torque available.

tained from figure 7-2-1. Available torque is presented

in terms of PA and FAT.

7-2-3. Conditions.

The chart is based on a rotor speed of 100%.

7-2-2. Use of Chart.

7-2-4. EAPS Installed.

The primary use of the chart is to determine available

engine torque for various combinations of PA and tem-

Reduce the derived torque available by 2.0% however

perature. To determine torque available, it is necessary

not at transmission torque limit.

7-2-1

TM 1-1520-240-10

Figure 7-2-1. Emergency Torque Available

7-2-2

TM 1-1520-240-10

SECTION III. MAXIMUM TORQUE AVAILABLE

7-3-1. Maximum Torque Available (10 Minute

7-3-4. Maximum Torque Available (30 Minute

Operation).

Maximum torque available (10 minute operation) may be

Maximum Torque Available (30 Minute Operation)

obtained from figure 7-3-1. Available torque is presented

may be obtained from figure 7-3-2. Available torque

in terms of pressure altitude and free air temperature.

is presented in terms of PA and FAT.

7-3-5. Use of Chart.

7-3-2. USE OF CHART.

The primary use of the chart is to determine available

engine torque for various combinations of pressure alti-

tude and temperature. To determine torque available, it

is necessary to know pressure altitude and free air tem-

perature. Enter the left side of the chart at known temper-

ature, move right to known pressure altitude, then down

to read intermediate torque available.

to read torque available.

7-3-6. Conditions.

7-3-3. Conditions.

The chart is based on a rotor speed of 100%.

7-3-7. EAPS Installed.

Reduce the derived torque available by 1.8% however

not at transmission torque limit.

7-3-1

TM 1-1520-240-10

Figure 7-3-1. Maximum Torque Available (10 - Minute Operation)

7-3-2

TM 1-1520-240-10

Figure 7-3-2. Maximum Torque Available (30 - Minute Operation)

7-3-3/(7-3-4 blank)

TM 1-1520-240-10

SECTION IV. CONTINUOUS TORQUE AVAILABLE

7-4-1. Continuous Torque Available.

to know PA and FAT. Enter the left side of the chart at

known temperature, move right to known pressure alti-

Continuous torque available may be obtained from figure

tude, then down to read torque available.

7-4-1. Available torque is presented in terms of PA and

FAT.

7-4-3. Conditions.

This chart is based on a rotor speed of 100%.

7-4-2. Use of Chart.

7-4-4. EAPS Installed.

The primary use of the chart is to determine available

engine torque for various combinations of PA and tem-

Reduce the derived torque available by 1.8% however

perature. To determine torque available, it is necessary

not at transmission torque limit.

7-4-1

TM 1-1520-240-10

Figure 7-4-1. Continuous Torque Available

7-4-2

TM 1-1520-240-10

SECTION V. HOVER

7-5-1. Description.

c. The hover charts may also be used to determine

maximum GW for hover at a given wheel height, PA, and

The hover chart, figure 7-5-1, presents torque required

temperature. Enter at known pressure altitude, move

to hover at 100% RRPM at various combinations of PA,

right to the FAT, then move down to the bottom of the

FAT, GW, and wheel height for single and dual engine

lower grid, and read density altitude. Now enter lower left

operation.

grid at maximum torque available. Move up to wheel

height, then move right to density altitude and read GW.

7-5-2. Use of Chart.

This is the maximum gross weight at which the helicopter

will hover.

a. The primary use of the charts is illustrated by the

example. To determine the torque required to hover, it is

7-5-3. Conditions.

necessary to know PA, FAT, GW, and desired wheel

height. Enter the upper right grid at the known pressure

a. The hover chart is based on calm wind, level

altitude, move right to the temperature, move down to

surface, and 100% RRPM.

gross weight. Move left to desired wheel height, deflect

b. Hover in ground effect (HIGE) data is based on

down and read torque required for dual engine or single

hovering over a level surface. For normal transition from

engine operation.

hover to forward flight, the minimum hover wheel height

b. n addition to the primary use, the hover ceiling

should be 10 feet to prevent ground contact. If helicopter

charts (fig. 7-5-2) may be used to predict maximum hover

is to hover over a surface known to be steep, covered

height. This information is necessary for use of the

with vegetation, or if type of terrain is unknown, the flight

takeoff chart found in figure 7-6-1. To determine

should be planned for hover out of ground effect (HOGE)

maximum hover height, it is necessary to know PA, FAT,

capability.

GW, and maximum torque available. Enter at the known

c. EAPS installation has negligible effect on hover

pressure altitude, move right to FAT, move down to gross

torque figure 7-5-1.

weight, move left to intersection with maximum torque

available and read wheel height. This wheel height is the

d. Hover ceiling charts, figure 7-5-2, with EAPS

maximum hover height.

installed, reduce gross weight by 700 pounds.

7-5-1

TM 1-1520-240-10

Figure 7-5-1. Hover Chart

7-5-2

TM 1-1520-240-10

Figure 7-5-2. Hover Ceiling

7-5-3/(7-5-4 blank)

TM 1-1520-240-10

SECTION VI. TAKEOFF

7-6-1. Description.

b. A hover check should be made prior to takeoff to

verify hover capability. If winds are present, hover

The takeoff chart, figure 7-6-1, defines distances re-

capability will be greater than predicted since the hover

quired to clear obstacles of 50 feet, 100 feet, 150 feet,

chart is based on calm wind conditions.

and 200 feet based upon maximum hover height capabil-

ity and true airspeed. The procedure for takeoff is the

level flight acceleration technique.

7-6-3. Conditions.

NOTE

The maximum hover heights shown are indica-

a. The takeoff chart is based on calm wind

tive of helicopter performance capability and do

conditions. Since the surface wind velocity and direction

not imply that this hover height must be main-

cannot be accurately predicted, all takeoff planning

tained through takeoff.

should be based on calm air conditions. Takeoff into the

wind will improve takeoff performance.

7-6-2. Use of Chart.

The primary use of the chart is illustrated by the exam-

ples.

CAUTION

a. To determine the distance required to clear an

obstacle, it is necessary to know maximum hover height

A tailwind during takeoff and climbout will

(hover capability), obstacle height, and climbout true

increase the distance for obstacle clearance

airspeed. Calculation of maximum hover height is

and may prevent a successful takeoff.

described in Section V, Hover. Enter the chart for the

required obstacle height, move right to desired true

climbout airspeed, then down and read distance required

b. Takeoff performance data are based on the use

to clear obstacle.

of maximum torque available at 100% RRPM.

7-6-1

TM 1-1520-240-10

Figure 7-6-1. Takeoff Chart

7-6-2

TM 1-1520-240-10

SECTION VII. CRUISE

7-7-1. Description.

b. Torque. Since PA and temperature are defined for

each chart, torque required varies only with GW and

The cruise charts, figures 7-7-1 through 7-7-84, present

airspeed. The torque required per engine as presented

torque requirements and fuel flow for cruise flight as a

on the charts is for dual engine operation. The torque

function of airspeed and gross weight for various com-

required for single engine operation is double the dual

binations of pressure altitude and free air temperature.

engine torque value for any given condition. See cruise

Dot pattern (shaded) area indicates time limited opera-

chart example 2 for example on torque required. With

tion.

EAPS installed there is no significant change in torque

required. The torque available limits shown are either

7-7-2. Use of Charts.

transmission or engine torque limits (whichever is least).

The primary use of charts is illustrated by the example

cruise chart (fig. 7-7-1). To use the charts it is usually

c. Fuel Flow. The fuel flow scales presented on each

necessary to know the planned PA, estimated FAT,

chart opposite the torque scales are for dual engine

planned cruise TAS, and the GW. First select the proper

operation. Torque may be converted directly to fuel flow

chart based on PA and free air temperature. Enter the

on any chart without regard to other chart information. A

chart at the cruise TAS, move right and read IAS, move

single engine fuel flow chart is presented in Section X.

left to the GW, move down and read torque required, then

Torque required for any given condition as obtained from

move up and read associated fuel flow. Maximum perfor-

the preceding cruise charts should be doubled before

mance conditions are determined by entering the chart

being used to obtain single engine fuel flow from this

where the maximum range line or maximum endurance

chart.

and rate of climb (R/C) line intersect the gross weight

line: then read airspeed, fuel flow, and torque required.

d. Maximum Range. Maximum range lines indicate

Normally, sufficient accuracy can be obtained by select-

optimum GW/cruise speed conditions with respect to

ing the chart nearest to the planned cruising altitude and

distance covered per pound of fuel consumed for zero

FAT, or move conservatively, by selecting the chart with

wind condition.

the next higher altitude and FAT (example cruise chart,

method one). If greater accuracy is required, interpola-

e. Maximum Endurance and Rate of Climb. Maxi-

tion between altitudes and/or temperatures is permissi-

mum endurance and rate of climb lines indicate opti-

ble (example cruise chart, method two). To be conserva-

mum GW / cruise speed conditions for maximum

tive, use the GW at the beginning of the cruise flight. For

endurance and maximum rate of climb. These condi-

improved accuracy or long flights, it is preferable to deter-

tions require minimum fuel flow (maximum endurance)

mine cruise information for several flight segments to

and provide maximum torque change for climb (maxi-

allow for decreasing GW.

mum rate of climb). This airspeed also represents the

best single engine airspeed.

a. Airspeed. True and indicated airspeeds are

presented at opposite sides of each chart. On any chart,

IAS can be directly converted to TAS (or vice versa) by

7-7-3. Conditions.

reading directly across the chart without regard to other

chart information. Estimated airspeed limits with an

The cruise charts are based on 100% RRPM for ambient

operating CGI appear as dashed lines on each chart.

temperatures of -10_C and above, and 98% and 100%

Airspeed limits with the CGI inoperative are presented

RRPM for ambient temperatures of -20_C and below.

in the airspeed limits section of Chapter 5.

NOTE

7-7-4. Performance Penalties with EAPS.

Airspeed limitations with an operative cruise

guide indicator are per the indicator display.

The engine performance loss with EAPS installed is

Estimated values shown on these cruise

shown in table 7-7-1. The corrections shown in the table

charts are for information only, as an aid to

are to be applied to the applicable to the applicable per-

pre-flight planning.

formance data shown on Chapter 7.

7-7-1

TM 1-1520-240-10

Table 7-7-1 EAPS Penalty Table

Increase Total

Decrease Torque Available (%)

Fuel Flow By

Pressure

OAT

(lb/hr)

KTAS = 0

135

160

Altitude (ft)

(_C)

Sea Level

-50

-40

-30

-20

-10

2000

-50

-40

-30

-20

-10

4000

-50

-40

-30

-20

-10

7-7-2

TM 1-1520-240-10

Table 7-7-1 EAPS Penalty Table (Continued)

Increase Total

Decrease Torque Available (%)

Fuel Flow By

Pressure

OAT

(lb/hr)

KTAS = 0

135

160

Altitude (ft)

(_C)

6000

-50

-40

-30

-20

-10

8000

-50

-40

-30

-20

-10

10000

-50

-40

-30

-20

-10

7-7-3

TM 1-1520-240-10

Table 7-7-1 EAPS Penalty Table (Continued)

Increase Total

Decrease Torque Available (%)

Fuel Flow By

Pressure

OAT

(lb/hr)

KTAS = 0

135

160

Altitude (ft)

(_C)

12000

-50

-40

-30

-20

-10

14000

-50

-40

-30

-20

-10

16000

-50

-40

-30

-20

-10

7-7-4

TM 1-1520-240-10

Table 7-7-1 EAPS Penalty Table (Continued)

Increase Total

Decrease Torque Available (%)

Fuel Flow By

Pressure

OAT

(lb/hr)

KTAS = 0

135

160

Altitude (ft)

(_C)

18000

-50

-40

-30

-20

-10

20000

-50

-40

-30

-20

-10

7-7-5

TM 1-1520-240-10

CRUISE EXAMPLE

EXAMPLE 2 (DUAL ENGINE)

EXAMPLE 1 (DUAL ENGINE)

(DASH LINE)

WANTED:

SPEED FOR MAXIMUM ENDURANCE

TORQUE REQUIRED FOR LEVEL FLIGHT, FUEL

SPEED FOR MAXIMUM RANGE

FLOW, AND INDICATED AIRSPEED AT TAS = 120

KN.

MAX. SPEED AT CONTINUOUS TORQUE RATING

ESTIMATED AIRSPEED LIMIT WITH CRUISE

KNOWN:

GUIDE INDICATOR OPERATIVE

GROSS WEIGHT = 45,000 LB.

PRESSURE ALTITUDE = SEA LEVEL

FAT = 35_C

KNOWN:

TRUE AIRSPEED = 120KN

GROSS WEIGHT = 50,000 LB.

PRESSURE ALTITUDE = SEA LEVEL

METHOD 1 (SIMPLEST)

FAT = 30_C

USE NEXT HIGHER TEMPERATURE (40_C)

ENTER TAS, MOVE RIGHT TO GROSS WEIGHT

MOVE DOWN READ TORQUE REQ’D = 55%

METHOD:

(PER ENGINE

READ SPEEDS WHERE GROSS WEIGHT LINE

MOVE UP READ FUEL FLOW = 2670 LB/HR

(TOTAL)

INTERSECTS PERFORMANCE OR LIMIT LINE

MOVE RIGHT READ IAS = 114 KN

MAXIMUM ENDURANCE: TAS = 89 KN, IAS = 83

METHOD 2 (INTERPOLATE)

MAXIMUM RANGE: TAS = 144 KN, IAS = 140 KN

READ TORQUE REQ’D, FUEL FLOW, AND IAS AT

EACH ADJACENT TEMPERATURE THEN INTER-

(REQUIRES POWER IN EXCESS OF MAX

POLATE BETWEEN TEMPERATURES

CONTINUOUS POWER)

MAX SPEED (CONTINUOUS TORQUE RATING):

(REFER TO TABLE BELOW)

TAS = 130 KN, IAS = 127 KN

ESTIMATED AIRSPEED LIMIT (VCGI): 152 KN

IAS = 148 KN

PRESSURE ALTITUDE

SEA LEVEL

FAT

30_C

40_C

35_C

TORQUE REQ’D (%)

54.7%

55%

54.9%

FUEL FLOW (LB/HR)

2620

2670

2645

IAS (KNOTS)

117

114

115.5

Figure 7-7-1. Example Cruise Chart (Sheet 1 of 2)

7-7-6

TM 1-1520-240-10

Figure 7-7-1 Example Cruise Chart (Sheet 2 of 2)

7-7-7

TM 1-1520-240-10

Figure 7-7-2. 98 and 100% Rotor RPM, -50_C, Sea Level

7-7-8

TM 1-1520-240-10

Figure 7-7-3. 98 and 100% Rotor RPM, -40_C, Sea Level

7-7-9

TM 1-1520-240-10

Figure 7-7-4. 98 and 100% Rotor RPM, -30_C, Sea Level

7-7-10

TM 1-1520-240-10

Figure 7-7-5. 98 and 100% Rotor RPM, -20_C, Sea Level

7-7-11

TM 1-1520-240-10

Figure 7-7-6. 100% Rotor RPM, -10_ and and 0_C, Sea Level

7-7-12

TM 1-1520-240-10

Figure 7-7-7. 100% Rotor RPM, 10_ and 20_C, Sea Level

7-7-13

TM 1-1520-240-10

Figure 7-7-8. 100% Rotor RPM, 30_ and 40_C, Sea Level

7-7-14

TM 1-1520-240-10

Figure 7-7-9. 100% Rotor RPM, 50_C, Sea Level

7-7-15

TM 1-1520-240-10

Figure 7-7-10. 98 and 100% Rotor RPM, -50_C, 2,000 Feet

7-7-16

TM 1-1520-240-10

Figure 7-7-11. 98 and 100% Rotor RPM, -40_C, 2,000 Feet

7-7-17

TM 1-1520-240-10

Figure 7-7-12. 98 and 100% Rotor RPM, -30_C, 2,000 Feet

7-7-18

TM 1-1520-240-10

Figure 7-7-13. 98 and 100% Rotor RPM, -20_C, 2,000 Feet

7-7-19

TM 1-1520-240-10

Figure 7-7-14. 100% Rotor RPM, -10_ and 0_C, 2,000 Feet

7-7-20

TM 1-1520-240-10

Figure 7-7-15. 100% Rotor RPM, 10_ and 20_C, 2,000 Feet

7-7-21

TM 1-1520-240-10

Figure 7-7-16. 100% Rotor RPM, 30_ and 40_C, 2,000 Feet

7-7-22

Content .. 6 7 8 9 ..