C141 Performance Data

7/25/2019 C141 Performance Data

1/333

TO 1C-141B-1-1

1 JUNE 2003

PUBLISHED UNDER AUTHORITY OF THE SECRETARY OF THE AIR FORCE

DISTRIBUTION STATEMENT Distribution authorized to the Department of Defense and U.S. DoDcontractors only (Administrative or Operational Use) (1 June 2003). Other requests for this documen

or questions concerning technical content should be referred to WR-ALC/LJET, Robins AFB GA31098.

WARNING This document contains technical data whose export is restricted by the Arms ExportControl Act (Title 22, U.S.C., Sec. 2751 et seq.) or the Export Administration Act of 1979, as

amended (Title 50, U.S.C., App. 2401et seq.). Violators of these export laws are subject to severecriminal penalties.

HANDLING AND DESTRUCTION NOTICE Comply with distribution statement and destroy by any

method that will prevent disclosure of the contents or reconstruction of the document.

APPENDIX I

PERFORMANCE DATA

C - 1 4 1 B / CTHIS PUBLICATION ISINCOMPLETE WITHOUT TO

1C- 141B-1 or 1C- 141C-1

FLIGHT MANUALUSAF SERIES AIRCRAFT

F09603-78-C-1473F09603-99-D-0382

COMMANDERS ARE RESPONSIBLE FOR BRINGING THIS PUBLICATION TO THE ATTENTION OFALL AIR FORCE PERSONNEL CLEARED FOR OPERATION OF SUBJECT AIRCRAFT.

THIS PUBLICATION SUPERSEDES TO 1C-141B-1-1S-7, DATED 18 FEBRUARY 1998, TO 1C-141B-

1-1SS-8, DATED 19 APRIL 1999, TO 1C-141B-1-1S-9, DATED 3 NOVEMBER 1999, TO 1C-141B-11S-10, DATED 20 SEPTEMBER 2000.


2/333

*Zero in this column indicates an original page.

TO 1C-141B-1-1

INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES.

LIST OF EFFECTIVE PAGESThe portion of the text affected by the changes is indicated by a vertical line in the marginsof the page. Changes to illustrations are indicated by miniature pointing hands. Changesto wiring diagrams are indicated by shaded areas.

NOTE:

A

Page *ChangeNo. No.

TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS 334, CONSISTING OF THE FOLLOWING:

Page *ChangeNo. No.

Page *ChangeNo. No.

Dates of issue for original and changed pages are:

USAF

Origina l . . . . . . . . . . 0 . . . . . . . . . . . . . . . . 1 June 2003

Title . . . . . . . . . . . . . . . . . . . . . . 0A . . . . . . . . . . . . . . . . . . . . . . . . 0i . . . . . . . . . . . . . . . . . . . . . . . . . 0ii Blank . . . . . . . . . . . . . . . . . . . 01-1 1-23 . . . . . . . . . . . . . . . . 01-24 Blank . . . . . . . . . . . . . . . . 02-1 2-7 . . . . . . . . . . . . . . . . . 02-8 Blank . . . . . . . . . . . . . . . . . 03-1 3-74 . . . . . . . . . . . . . . . . 04-1 4-14 . . . . . . . . . . . . . . . . 05-1 5-64 . . . . . . . . . . . . . . . . 06-1 6-7 . . . . . . . . . . . . . . . . . 06-8 Blank . . . . . . . . . . . . . . . . . 07-1 7-10 . . . . . . . . . . . . . . . . 0

8-1 8-36 . . . . . . . . . . . . . . . . 09-1 9-27 . . . . . . . . . . . . . . . . 09-28 Blank . . . . . . . . . . . . . . . . 010-1 10-12 . . . . . . . . . . . . . . 011-1 11-24 . . . . . . . . . . . . . . 012-1 12-27 . . . . . . . . . . . . . . 012-28 Blank . . . . . . . . . . . . . . . 0


3/333

i/(ii blank

TO 1C-141B-1-1

APPENDIX ....... Iperformance data

TABLE OF CONTENTS

PART 1. INTRODUCTION ....................................................................................................................... 1-1

PART 2. ENGINE DATA ......................................................................................................................... 2-1

PART 3. TAKE-OFF AND CLIMB........................................................................................................... 3-1

PART 4. ENROUTE CLIMB .................................................................................................................... 4-1

PART 5. RANGE...................................................................................................................................... 5-1

PART 6. ENDURANCE ............................................................................................................................ 6-1

PART 7. DESCENT ................................................................................................................................. 7-1

PART 8. APPROACH AND LANDING.................................................................................................... 8-1

PART 9. AIRDROP DATA ....................................................................................................................... 9-1

PART 10. AIR REFUELING DATA ........................................................................................................... 10-1

PART 11. ABNORMAL CONFIGURATION DATA ................................................................................... 11-1

PART 12. MISSION PLANING ................................................................................................................. 12-1


4/333


5/333

1-1

TO 1C-141B-1-1

PART 1. INTRODUCTION

TABLE OF CONTENTS

Paragraph Page

Abbreviations Used in the Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Basis for Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Pressure Altitude Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Airspeed and Altimeter Position Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Temperature and Speed Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Stall Speeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

LIST OF CHARTS

Figure Title Page

1-1 Abbreviations and Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

1-2 ICAO Standard Atmosphere Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1-3 SMOE 1/ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

1-4 Temperature Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

1-5 Temperature Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

1-6 True Mach Number - Calibrated Airspeed Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

1-7 True Mach Number - True Airspeed Conversion (For Mission Planning) . . . . . . . . . . . . . . . . . . . . 1-11

1-8 True Mach Number - True Airspeed Conversion (For Inflight Use) . . . . . . . . . . . . . . . . . . . . . . . . . 1-12

1-9 Altitude Pressure Table - Inches Hg. vs Feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13

1-10 Stall Speeds - Gear Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16

1-11 Stall Speeds - Gear Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18

1-12 Shaker Onset Speeds (B-model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20

1-13 Buffet Boundary Stick Shaker Speed Envelope (B-model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21

1-14 Shaker Onset Speeds (C-model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22


6/333

TO 1C-141B-1-1

1-2

ABBREVIATIONS USED IN THE AP-PENDIX.

The abbreviations used throughout this Appendix are

defined in figure 1-1.

BASIS FOR CHARTS.

The performance data presented in this Appendix are

applicable to the TF33-P-7 engine using JP-4 fuel

weighing 6.5 pounds per gallon. Unless an ICAO

Standard Day is specified, it may be assumed that

the data are valid for all temperature conditions. The

term "Std Day" used in some line labels means an

ICAO standard day. (See figure 1-2.)

PRESSURE ALTITUDE DEFINITION.

In actual air at a given true altitude, the pressuremay d i f fe r f rom s tandard a i r va lues . I f the

atmospheric pressure is measured at the aircraft

level, an altitude corresponding to this pressure

can be determined from a standard air table. This

altitude is known as the pressure altitude of the

aircraft. It is also the altitude recorded by the

altimeter if the altimeter has no instrument error

and is set to 29.92. The altimeter will read true

altitude when in a standard atmosphere and set at

29.92. It will read higher or lower than the true

altitude in a non-standard atmosphere. Most of the

charts are based on pressure altitude and are so

titled. Some data are presented only for standardconditions, and in these cases the altitude scales

are merely titled "ALTITUDE." For such charts use

pressure altitude.

AIRSPEED AND ALTIMETER POSITION

CORRECTIONS.

The CADC compensates for airspeed and altimeter

position errors. All Mach number data shown in the

Appendix are true Mach numbers. Airspeeds are shown

as calibrated airspeeds or true airspeeds. The calibrated

airspeed scales are increased by 3 knots to accountfor the difference between the airspeed observed by

the pilots and the actual speed of the aircraft. At

groundspeeds between 100 and 60 knots, when near

maximum reverse thrust is used, all pitot-static

instruments may operate erratically, and airspeed

indicators may go to 50 knots.

TEMPERATURE AND SPEED CONVER-SION.

CONVERSION OF INDICATED OAT (TOTAL TEM-PERATURE) TO TRUE OAT (AMBIENT TEM-PERATURE).

Because of ram effect, total temperature must be

corrected to obtain OAT (figure 1-4). Temperatures

presented in this appendix are OAT or as indicated

on the chart.

CAUTION

The Total Temp gauge shall not be used for

take-off calculations since heat radiation can

cause considerable error.

TEMPERATURE CONVERSION CHART.

To convert temperatures in degrees Centigrade to

degrees Fahrenheit or Fahrenheit to Centigrade, use

figure 1-5.

MACH NUMBER-AIRSPEED CONVERSION.

Figure 1-6 provides a conversion between true Mach

number and calibrated airspeed. True Mach number

may be converted to true airspeed with figures 1-7

and 1-8.

PRESSURE ALTIMETER SETTING CONVER-SION CHART.

Figure 1-9 converts take-off or landing field

barometric pressure to field pressure altitude when

only altimeter setting and actual field elevation is

known. Enter the table at the left with the field

altimeter setting to the nearest tenth (first decimal).

Proceed horizontally to the right until the column

indicating the second decimal of the altimeter setting

is reached. The number read in this column should

be applied as a correction to the actual field elevation,

to obtain field pressure altitude.

1/

A chart of SMOE (1/ ) is provided in figure 1-3.This chart is used in converting KCAS to true air

speed.


7/333

1-3

TO 1C-141B-1-1

STALL SPEEDS

Figure 1-10 and 1-11 show stall speeds in the various

angles of bank and flap configurations.

STICK SHAKER ONSET SPEEDS AND STICK

SHAKER ENVELOPES (C-141B)

Figure 1-12 shows stick shaker speeds, in the various

angles of bank and flap configurations. The speed

envelope or buffet boundary for stick shaker operation

is presented in figure 1-13 for various altitudes, gross

weights and Mach numbers. In the cruise configuration,

stick shaker and natural buffet occur simultaneously

for Mach numbers up to 0.70. At higher Mach numbers,

natural buffet occurs earlier. With flaps extended natural

buffet will always precede the stick shaker.

STICK SHAKER ONSET (C-141C)

The stall warning computer has been removed and the

stall warning function is now embedded in both Automatic

Flight Control Processors. A new algorithm has been

developed to calculate shaker onset. The speed at which

shaker onset occurs is influenced by aircraft configuration

Refer to figures 9-18 for Shaker Onset Speeds.

Example.

Given: Mach Number = 0.58

Pressure Altitude = 30,000 feet

Gross Weight = 250,000 pounds

Find: Bank angle where shaker onset

Mach number for natural aircraft buffet

occurs before stick shaker

Solution: Bank angle = 51 degrees

Natural buffet = 0.81

Speeds in the pattern are determined from the approach

speed, derived from figure 8-8, for the selected flap

configuration for landing.


8/333

TO 1C-141B-1-1

1-4

ABBREVIATIONS AND DEFINITIONS

Abbreviation Definition

ACN/PCN Aircraft Classification Number/Pavement Classification Number

AGL Above Ground Level

ALT AltitudeARCP Air Refueling Control Point

AUW All Up Weight

BDP Begin Descent Point

CBR California Bearing Ratio

CG, cg Center of Gravity - (in percent of mean aerodynamic chord, MAC)

CFL Critical Field Length (Feet)

CFP Computerized Flight Plan

CL TO Climb To

COF Climbout Factor

C Degrees Centigrade

DER Departure End of Runway

EGT Exhaust Gas Temperature

EPR Engine Pressure Ratio - (The ratio of engine turbine exit pressure to

compressor inlet pressure)

ESWL Equivalent Single Wheel Load

F Degrees Fahrenheit

FL Flight Level

FPM, fpm Feet Per Minute

FT, ft Feet

g Acceleration Due to Gravity

GW Gross Weight

GW 3 ENG Gross Weight Limited by 3 Engine Climb Performance

GW 4 ENG Gross Weight Limited by 4 Engine Climb Performance

GWCFL Gross Weight Limited by Critical Field Length

GWOBST Gross Weight Limited by Obstacle Clearance

GW(SCREEN) Gross Weight Screen Height

Hg Mercury

ICAO International Civil Aviation Organization

IOAT Total Temperature - Outside Air Temperature plus Temperature Rise Caused

by Ram Effect

K Constant

L/D Lift Over Drag Ratio

LB, lb Pounds

LB/HR Pounds Per Hour

LCN Loading Classification Number

LDG Landing

LRC Long Range CruiseMAC Mean Aerodynamic Chord

MRT Military Rated Thrust

MSL Mean Sea Level

%N1 Percent of the engine low-pressure compressor rotor revolutions per minute

(for this aircraft 100%N1 is 6,796 revolutions per minute)

%N2 Percent of the engine high-pressure compressor rotor revolutions per minute

(for this aircraft 100%N2 is 9,655 revolutions per minute)

NM Nautical Miles (6,076 ft)

Figure 1-1. (Sheet 1 of 2)


9/333

1-5

TO 1C-141B-1-1

NRT Normal Rated Thrust - (Maximum allowable thrust for continuous operation

determined by EPR setting)

OAT Outside Air Temperature - (The actual ambient air temperature)

OBS Obstacle

OBST Obstacle

PA Pressure Altitude

PPH Pounds Per Hour

R/C Rate of Climb (Feet per minute)

RA Runway Available (Feet)

RCR Runway Condition Reading

RL Runway Length (Feet)

RPM. rpm Revolutions Per Minute (For this aircraft, the revolutions per

minute of the engine high/low pressure compressor rotor)

RSC Runway Surface Covering

Sec Seconds (Time)

SID Standard Instrument DepartureSL Sea Level Altitude

T & GO Touch and Go

TD Touchdown

TEMP DEV Temperature Deviation front Standard Day

TF Thrust Factor

TOF Take-off Factor

TRT Take-off Rated Thrust

ZFW Zero Fuel Weight

SPEEDS:

CAS Calibrated Airspeed (Indicated airspeed corrected for

installation error) (Corrected by CADC)

EAS Equivalent Airspeed (CAS corrected for compressibility error)IAS Indicated Airspeed. The airspeed displayed by the airspeed

indicator (Standby airspeed)

M Mach Number

TAS True Airspeed (EAS corrected for air density)

VAPP

Approach Speed

VB(MAX) Maximum Braking Speed

VCEF

Critical Engine Failure Speed

VGO

GO Speed

VHR

Restricted Level Flight Speed

VL

Dive Speed Limit

VMCA

Air Minimum Control Speed

VMCG

Ground Minimum Control Speed

VMCO

Minimum Climbout Speed

VMFR

Minimum Flap Retract Speed

VMS

Minimum Spoiler Speed

VR

Refusal Speed

VROT

Rotation Speed

VS

Stall Speed

VSHO

Shaker Onset Speed

X-Wind Crosswind


ABBREVIATIONS AND DEFINITIONS

Abbreviation Definition


10/333

TO 1C-141B-1-1

1-6

0 1.0000 1.0000 15.000 59.0 661.7 1013.2 29.92 1.0000

1,000 .9711 1.0148 13.019 55.4 659.5 977.3 28.86 .9644

2,000 .9428 1.0299 11.037 51.9 657.2 942.1 27.82 .9298

3,000 .9151 1.0454 9.056 48.3 654.9 908.2 26.82 .8962

4,000 .8881 1.0611 7.075 44.7 652.6 875.0 25.84 .8637

5,000 .8617 1.0773 5.094 41.2 650.3 843.2 24.90 .8320

6,000 .8359 1.0937 3.113 37.6 647.9 812.1 23.98 .8014

7,000 .8106 1.1107 1.132 34.0 645.6 781.9 23.09 .7716

8,000 .7860 1.1279 -.850 30.5 643.3 752.5 22.22 .7428

9,000 .7620 1.1456 -2.831 26.9 640.9 724.3 21.39 .7148

10,000 .7385 1.1637 -4.812 23.3 638.6 696.9 20.58 .6877

11,000 .7156 1.1822 -6.794 19.8 636.2 670.2 19.79 .6614

12,000 .6932 1.2011 -8.775 16.2 633.9 644.4 19.03 .6360

13,000 .6713 1.2204 -10.756 12.6 631.5 619.4 18.29 .611314,000 .6500 1.2404 -12.737 9.1 629.1 595.3 17.58 .5874

15,000 .6292 1.2607 -14.718 5.5 626.7 572.0 16.89 .5643

16,000 .6090 1.2814 -16.700 1.9 624.3 549.3 16.22 .5420

17,000 .5892 1.3028 -18.681 -1.6 621.9 527.3 15.57 .5203

18,000 .5699 1.3247 -20.662 -5.2 619.4 505.9 14.94 .4994

19,000 .5511 1.3470 -22.643 -8.8 617.0 485.6 14.34 .4791

20,000 .5328 1.3701 -24.624 -12.3 614.6 465.6 13.75 .4595

21,000 .5150 1.3935 -26.605 -15.9 612.1 446.3 13.18 .4406

22,000 .4976 1.4176 -28.587 -19.5 609.6 428.0 12.64 .4223

23,000 .4806 1.4424 -30.568 -23.0 607.2 410.1 12.11 .4046

24,000 .4642 1.4678 -32.549 -26.6 604.7 392.8 11.60 .3876

25,000 .4481 1.4939 -34.530 -30.2 602.2 375.9 11.10 .3711

26,000 .4325 1.5207 -36.511 -33.7 599.7 360.0 10.63 .3552

27,000 .4173 1.5480 -38.492 -37.3 597.2 344.4 10.17 .3398

28,000 .4025 1.5763 -40.473 -40.9 594.7 329.2 9.72 .325029,000 .3881 1.6051 -42.455 -44.4 592.1 314.9 9.30 .3107

30,000 .3741 1.6348 -44.436 -48.0 589.5 301.1 8.89 .2970

31,000 .3605 1.6656 -46.417 -51.6 587.0 287.5 8.49 .2837

32,000 .3473 1.6969 -48.398 -55.1 584.4 274.6 8.11 .2709

33,000 .3345 1.7292 -50.380 -58.7 581.8 262.1 7.74 .2586

34,000 .3220 1.7624 -52.361 -62.2 579.2 249.9 7.38 .2467

35,000 .3099 1.7963 -54.342 -65.8 576.7 238.4 7.04 .2353

36,000 .2981 1.8315 -56.324 -69.4 574.0 227.2 6.71 .2243

37,000 .2844 1.8753 -56.500 -69.7 573.8 216.7 6.40 .2138

38,000 .2710 1.9210 -56.500 -69.7 573.8 206.6 6.10 .2038

39,000 .2583 1.9677 -56.500 -69.7 573.8 196.7 5.81 .1942

40,000 .2462 2.0155 -56.500 -69.7 573.8 187.6 5.54 .1851

41,000 .2346 2.0646 -56.500 -69.7 573.8 178.8 5.28 .1764

42,000 .2236 2.1148 -56.500 -69.7 573.8 170.3 5.03 .1681

43,000 .2131 2.1662 -56.500 -69.7 573.8 162.2 4.79 .160244,000 .2031 2.2189 -56.500 -69.7 573.8 150.8 4.57 .1527

45,000 .1936 2.2729 -56.500 -69.7 573.8 147.3 4.35 .1455

46,000 .1845 2.3282 -56.500 -69.7 573.8 140.5 4.15 .1387

47,000 .1758 2.3848 -56.500 -69.7 573.8 134.1 3.96 .1322

48,000 .1676 2.4428 -56.500 -69.7 573.8 127.7 3.77 .1260

49,000 .1597 2.5022 -56.500 -69.7 573.8 121.6 3.59 .1201

50,000 .1522 2.5631 -56.500 -69.7 573.8 115.8 3.42 .1144

Standard Sea Level Air: Po

= 14.70 lb/sq in . = 29.921 in . of Hg 1 in. Hg = 70.727 lb/sq f t = 0 .49116 lb /sq in.

T = 15C (59F) w = 0.07651 lb/cu ft 0

= 0.002378 slugs/cu f t

ICAO STANDARD ATMOSPHERE TABLE

MILLI-BARS RATIO -

PP

O

PRESSURE DENSITY 1 TEMPERATURE SPEED OF PRESSUREALTITUDE RATIO - SOUND -

-FEET DEG C DEG F KNOTSIN. Hg

Figure 1-2.


11/333

1-7

TO 1C-141B-1-1

Figure 1-3.

0.90

0.92

0.94

0.96

0.98

1.00

1.02

1.04

1.06

1.08

1.101

1.12

1.14

1.16

1.18

1.20

1.22

1.24

1.26

1.28

1.30

4

3

2

1

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

60 40 20 0 20 40 60

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

-1

DE

NSITYALTITUDE-1000FEET

TEMPERATURE - C

1

PRESS.

ALT1

,000

FT.

STDD

AY

SMOE


12/333

TO 1C-141B-1-1

1-8

Figure 1-4.

350

300

250

200

CALIBRATED

AIRSPEED-KNOTS

TEMP DEV FROM STD - C

TRUEO

AT-C

MODEL: C-141BTF33-P-7 ENGINES

DATE: JUNE 1965DATA BASIS:C-141A CATEGORY IIFLIGHT TEST

150

100

40

20

20 10 0 -10 -20

-120

-100

-80

-60

-40

-20

0

3536ANDA

BOVE

PRESS.AL

T-1,000FT

30

25

20

15

10

5

SL

-80INDIC

ATEDO

AT-C

-70

-60

-50

-40

-30

-20

-10

0

10

20

30

40

SL

105

1520

2530

3540

PRESS.ALT-1,000FT

TEMPERATURE CORRECTION


13/333

1-9

TO 1C-141B-1-1

-60

F=(9/5)+32C=5/9(F-32)

130

120

110

100

90

80

70

60

50

40

30

20

10

-10

-20

-30

-40

-50

-60

-70

-80-60 -50 -40 -30 -20

DEGREES CENTIGRADE-10 0 10 20 30 40 50 60

0

-50 -30 -20 -10 0 10 20 30 40 50 60-40

D

EGREESFAHRENHEIT

DEGREES CENTIGRADE

TEMPERATURE CONVERSION

Figure 1-5.


14/333

TO 1C-141B-1-1

1-10

420

MODEL C-141BTF33-P-7 ENGINES


TRUE MACH NUMBER-CALIBRATED

AIRSPEED CONVERSION

400

380

360

340

320

300

280

260

CALIBRATEDAIRSPEED-KNOTS

240

220

200

180

160

140

120

1000.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

TRUE MACH NUMBER

S.L.

PRES

S.ALT

-1,000

FT

10

20

30

40

50

Figure 1-6.


15/333

1-11

TO 1C-141B-1-1

Figure 1-7.

0.4

0.3220 260 300 340

TRUE AIRSPEED - KNOTS



TRUEMACHNUMBERS

380 420 460 500 54

0.5

0.6

0.7

0.8

0.9

(FOR MISSION PLANNING)

TRUE MACH NUMBER-TRUE AIRSPEED CONVERSION

PRESS.AL

T-1,0

00FT

36ANDU

P

S.L.

STANDARD DAY

510

30

25

1520


16/333

TO 1C-141B-1-1

1-12

Figure 1-8 .

0.4

0.3220 260 300 340

TRUE AIRSPEED - KNOTS



TRUEMACHN

UMBERS

380 420 460 500 540

0.5

0.6

0.7

0.8

0.9

(FOR INFLIGHT USE)

TRUE MACH NUMBER-TRUE AIRSPEED CONVERSION

TRUEO

AT-C

-40-60

-20 020

40

IOAT must be converted to true OAT.

NOTE


17/333

1-13

TO 1C-141B-1-1


ALTITUDE PRESSURE TABLE INCHES Hg Vs FEET

Inches 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

28.0 1824 1814 1805 1795 1785 1776 1766 1756 7446 173728.1 1727 1717 1707 1698 1688 1678 1668 1659 1649 1639

28.2 1630 1620 1610 1601 1591 1581 1572 1562 1552 1542

28.3 1533 1523 1513 1504 1494 1484 1475 1465 1456 144628.4 1436 1427 1417 1407 1398 1388 1378 1369 1359 1350

28.5 1340 1330 1321 1311 1302 1292 1282 1273 1263 1254

28.6 1244 1234 1225 1215 1206 1196 1186 1177 1167 1158

28.7 1148 1139 1129 1120 1110 1100 1091 1081 1072 106228.8 1053 1043 1034 1024 1015 1005 995 986 976 967

28.9 957 948 938 929 919 910 900 891 881 87229.0 863 853 844 834 825 815 806 796 787 777

29.1 768 758 749 739 730 721 711 702 692 683

29.2 673 664 655 645 636 626 617 607 598 58929.3 579 570 560 551 542 532 523 514 504 495

29.4 485 476 467 457 448 439 429 420 410 401

29.5 392 382 373 364 354 345 336 326 318 30829.6 298 289 280 270 261 252 242 233 224 215

29.7 205 196 187 177 168 159 149 140 131 12229.8 112 103 94 85 75 66 57 47 38 2929.9 20 10 +1 -8 -17 -26 -36 -45 -54 -63

30.0 -73 -82 -91 -100 -110 -119 -128 -137 -146 -156

30.1 -165 -174 -183 -192 -202 -211 -220 -229 -238 -248

30.2 -257 -266 -275 -284 -293 -303 -312 -321 -330 -33930.3 -348 -358 -367 -376 -385 -394 -403 -412 -421 -431

30.4 -440 -449 -458 -467 -476 -485 -494 -504 -513 -52230.5 -531 -540 -549 -558 -567 -576 -585 -594 -604 -613

30.6 -622 -631 -640 -649 -658 -667 -676 -685 -694 -703

30.7 -712 -721 -730 -740 -749 -758 -767 -776 -785 -79430.8 -803 -812 -821 -830 -839 -848 -857 -866 -875 -884

30.9 -893 -902 -911 -920 -929 -938 -947 -956 -965 -974

31.0 -983 -992 -1001 -1010 -1019 -1028 -1037 -1046 -1055 -1064


18/333

TO 1C-141B-1-1

1-14


Inches

940 27.76 27.79 27.82 27.85 27.88 27.91 27.94 27.96 27.99 28.02

950 28.05 28.08 28.11 28.14 28.17 28.20 28.23 28.26 28.29 28.32

960 28.35 28.38 28.41 28.44 28.47 28.50 28.53 28.56 28.59 28.61

970 28.64 28.67 28.70 28.73 28.76 28.79 28.82 28.85 28.88 28.91

980 28.94 28.97 29.00 29.03 29.06 29.09 29.12 29.15 29.18 29.21990 29.23 29.26 29.29 29.32 29.35 29.38 29.41 29.44 29.47 29.50

1000 29.53 29.56 29.59 29.62 29.65 29.68 29.71 29.74 29.77 29.80

1010 29.83 29.85 29.88 29.91 29.94 29.97 30.00 30.03 30.06 30.09

1020 30.12 30.15 30.18 30.21 30.24 30.27 30.30 30.33 30.36 30.39

1030 30.42 30.45 30.47 30.50 30.53 30.56 30.59 30.62 30.65 30.68

1040 30.71 30.74 30.77 30.80 30.83 30.86 30.89 30.92 30.95 30.98

1050 31.01 31.04 31.07 31.10 31.12 31.15 31.18 31.21 31.24 31.27

Thousandths of an inch

Inches of Mercury 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009

Millibars 0.0 0.1 0.1 0.1 0.2 0.2 0.2 0.3 0.3

BAROMETRIC READINGS FROM *MILLIBARS TO INCHES

Millibars 0 1 2 3 4 5 6 7 8 9


19/333

1-15

TO 1C-141B-1-1


METERS FEET METERS FEET METERS FEET METERS FEET

10 33 1,900 6,234 5,486 17,998 9,100 29,855

20 66 2,000 6,562 5,500 18,044 9,144 30,000

30 98 2,100 6,890 5,600 18,372 9,200 30,183

45 148 2,134 7,001 5,700 18,701 9,300 30,51150 164 2,200 7,218 5,791 18,999 9,400 30,840

61 200 2,300 7,546 5,800 19,029 9,449 31,000

92 302 2,400 7,874 5,900 19,357 9,500 31,168

100 328 2,438 7,999 6,000 19,685 9,600 31,496

123 404 2,500 8,202 6,096 20,000 9,700 31,824

153 502 2,600 8,530 6,100 20,013 9,754 32,001

183 600 2,700 8,858 6,200 20,341 9,800 32,152

200 656 2,743 8,999 6,300 20,669 9,900 32,480

214 702 2,800 9,186 6,400 20,997 10,000 32,808

244 801 2,900 9,514 6,401 21,000 10,059 33,002

250 820 3,000 9,842 6,500 21,325 10,100 33,136

274 899 3,048 10,000 6,600 21,653 10,200 33,464

300 984 3,100 10,170 6,700 21,981 10,300 33,792

305 1,001 3,200 10,499 6,800 22,309 10,363 33,999

350 1,148 3,300 10,827 6,900 22,638 10,400 34,120

400 1,312 3,353 11,001 7,000 22,966 10,500 34,448

450 1,476 3,400 11,155 7,010 22,998 10,600 34,776

457 1,499 3,500 11,483 7,100 23,294 10,668 35,000

500 1,640 3,600 11,811 7,200 23,622 10,700 35,105

550 1,804 3,658 12,001 7,300 23,950 10,800 35,433

600 1,968 3,700 12,139 7,315 23,999 10,900 35,761

610 2,001 3,800 12,467 7,400 24,278 10,973 36,000

650 2,133 3,900 12,795 7,500 24,606 11,000 36,089

700 2,297 3,962 12,999 7,600 24,934 11,100 36,417

750 2,461 4,000 13,123 7,620 25,000 11,200 36,745762 2,500 4,100 13,451 7,700 25,262 11,278 37,001

800 2,625 4,200 13,779 7,800 25,590 11,300 37,073

850 2,789 4,267 13,999 7,900 25,918 11,400 37,401

900 2,953 4,300 14,107 7,925 26,000 11,500 37,729

914 2,999 4,400 14,436 8,000 26,246 11,583 38,002

950 3,117 4,500 14,764 8,100 26,574 11,600 38,057

1,000 3,281 4,572 15,000 8,200 26,903 11,700 38,385

1,100 3,609 4,600 15,092 8,230 27,001 11,800 38,713

1,200 3,937 4,700 15,420 8,300 27,231 11,887 38,999

1,219 3,999 4,800 15,748 8,400 27,559 11,900 39,042

1,300 4,265 4,877 16,000 8,500 27,887 12,000 39,370

1,400 4,593 4,900 16,076 8,535 28,002 12,100 39,6981,500 4,921 5,000 16,404 8,600 28,215 12,192 40,000

1,524 5,000 5,100 16,732 8,700 28,543 12,200 40,026

1,600 5,249 5,182 17,001 8,800 28,871 12,300 40,354

1,700 5,577 5,200 17,060 8,839 28,999 12,400 40,682

1,800 5,905 5,300 17,388 8,900 29,199 12,497 41,000

1,829 6,001 5,400 17,716 9,000 29,527 12,500 41,010

ALTITUDE CONVERSION TABLE (METERS X 3.2808 = FEET)


20/333

TO 1C-141B-1-1

1-16


DATE: MAY 1983DATA BASIS:FLIGHT TEST

BANKAN

GLE-DEGREES

REFERENCENUMBER

STALL SPEEDSGEAR DOWN

60

50

40

30

20

10

0

0

1

2

3

4

5

6

7

8

9

SL

5

1015

20

25

30

35

4045

50

PRESS.

ALT-1,000FT

GRO

SSWEIG

HT-

1,000PO

UNDS

140

160

180

200

220

240

260

280

300320340

345



21/333

1-17

TO 1C-141B-1-1

REFERENCENUMBER

CALIBRATED

AIRSPEED-KNOTS

STALL SPEEDSGEAR DOWN

260

240

220

200

180

160

140

120

100

80

00.1 0.2 0.3 0.4 0.5

1

2

3

4

5

6

7

8

9

MACH NUMBER

PRES

S.ALT

-1,

000

50

0

FLAPS

ETTING

-PER

CENT

40

45

25

3530

252

015

10

5075

5SL

100



22/333

TO 1C-141B-1-1

1-18


DATE: MAY 1983DATA BASIS: FLIGHT TEST

BANKANGLE-DEGREES

REFERENCENUMBER

STALL SPEEDSGEAR UP

60

50

40

30

20

10

0

0

1

2

3

4

5

6

7

8

9

SL

510

15

20

25

30

35

4045

50

PRESS.A

LT-1,000FT

GRO

SSWEIG

HT-

1,000PO

UNDS

140

160

180

200

220

240

260

280

300

32

0

340

345



23/333

1-19

TO 1C-141B-1-1


CALIBRATEDA

IRSPEED-KNOTS

STALL SPEEDS GEAR UP

260

VSTALL

240

220

200

180

160

140

120

100

80

0.1 0.2 0.3 0.4 0.5 0.6 0.7

1

2

3

4

5

6

7

8

9

MACH NUMBER

REFERENCENUMBER

0

0

FLAPS

ETTING

-PER

CENT

FLAPLIMITSPEE

D

2550

7510

0

PRES

S.ALT

-1,

000

3530

2520

1510

5SL

45

50

40


24/333

TO 1C-141B-1-1

1-20

200

180

160

140

120

100

160

140

120

100

160

140

120

100

80403020340300260220180140

80


DATE:MAY 1983

DATA BASIS: FLIGHT TEST

CALIBRATEDAIRSPEED-KNOTS

GROSS WEIGHT - 1,000 POUNDS CG - PERCENT MAC

Applicable only for speeds belowMach 0.25.

BANKAN

GLE-DE

GREES

30

15

0

45

BANKAN

GLE-DE

GREES

BANKANGLE-

DEGREES

30

15

0

45

30

15

0

45

FLAPS-UPGEAR UP

FLAPS - 75 PERCENTGEAR UP

FLAPS - LANDINGGEAR DOWN

BA

SELINE

SHAKER ONSET SPEEDS(B-MODEL)

NOTE

Figure 1-12.


25/333

1-21

TO 1C-141B-1-1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Solid curve indicates region (below 0.70 MACH) where both stick shakeroperation and natural buffet occur simultaneously. the dashed curveindicates where natural buffet occurs prior to stick shaker.Flaps and gear up.

1.

2.

60

50

40

30

ANGLEOFBANK-DE

GREES

MACHNUMBER

LOADFACTOR-G

'S

20

10

0

1.02

1.00

1.06

1.15

1.30

1.55

2.00

NATURALBUFFET

NATURAL BUFFETAND STICK SHAKERSIMULTANEOUSLY

45

40

30

25

20

15

10

140

GRO

SSW

EIGHT

-1,000

POU

NDS

160

180

200

220

240

260

280

300

320

340

345

5

SL

PRESS.

ALT-

1,000FT

35

BUFFET BOUNDARY STICKSHAKER SPEED ENVELOPE

(B-MODEL)


DATE: OCTOBER 1968DATA BASIS:C-141A CATEGORY IIFLIGHT TEST NOTE

Figure 1-13.


26/333

TO 1C-141B-1-1

1-22


0

10

20

30

40

50

60

BANKANGLE-DEGREES

REFERENCENUMBER

0

1

2

3

4

5

6

7

8

9

GRO

SSWEIG

HT

-

1,000PO

UND

S

345

PRESSURE

ALTITUDE

1,000FE

ET

SL

5

10

15

20

25

30

3540

4550

340

140

160

180

200

220

240

260

280

300

320

SHAKER ONSET SPEEDSGEAR UP

(C-MODEL)

MODEL: C-141CTF33-P-7 ENGINES

DATE: MAY 2000DATA BASIS: AIRCRAFTAIRCRAFT FLIGHT TEST


27/333


1-23/(1-24 blank

TO 1C-141B-1-1

0

1

2

3

4

5

6

7

8

9

0.1 0.2 0.3 0.4 0.5 0.6 0.7

MACH NUMBER

REFERENCENUMBER

80

100

120

140

160

180

200

220

240

260

CALIBRATEDAIRSP

EED-KNOTS

SHAKER ONSET SPEEDSGEAR UP

PRES

SURE

ALTITUDE

-

1,00

0FE

ET SL

5

10

15

20

25

30

35

40

45

50

NATURAL

BUFFET

FLAPS

ETTING

-

PERC

ENT

SHAKER

OPERATION

100

75

50

25

0

(C-MODEL)


28/333


29/333

2-1

TO 1C-141B-1-1

PART 2. ENGINE DATA

TABLE OF CONTENTS

Paragraph Page

Conditions Affecting Engine Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Take-Off Rated Thrust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Reduced Thrust Take-Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Go-Around . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Reverse Thrust Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

LIST OF CHART

Figure Title Page

2-1 Take-off Rated Thrust, EPR Setting - Air Conditioning Pressurization On . . . . . . . . . . . . . . . . . . 2-3

2-2 Take-off Rated Thrust, EPR Setting - Air Conditioning Pressurization Off . . . . . . . . . . . . . . . . . . 2-4

2-3 Go-Around EPR Setting - Air Conditioning Pressurization On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

2-4 Thrust Reverse Limiter Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

2-5 Low Speed Compressor - Take-Off EPR Setting Static . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7


30/333

TO 1C-141B-1-1

2-2

CONDITIONS AFFECTING ENGINEPERFORMANCE.

The three basic conditions which influence engine

performance are:

1. Temperature

2 . Pressure altitude

3. Bleed ai r for operat ing systems

ENGINE THRUST AND AIR DENSITY.

The take-off distance for a given gross weight is

affected by engine thrust and air density. Engine thrust

and air density depend upon temperature and pressure

altitude. Relative humidity has little effect and may

be disregarded.

EFFECT OF OPERATING SYSTEMS REQUIR-ING BLEED AIR.

The use of engine bleed air for systems operation

reduces thrust available for a given throttle setting

under all conditions of take-off and flight. The number

of bleed air systems to be operated depends on

climatic conditions. The charts reflect the penalty

for typical operations. Variations in EPR reductions

for "Rain Removal ON," noted on the Take-Off Rated

thrust EPR setting charts, are caused by the variation

of total bleed requirements. If wing anti-ice isrequired after lift-off, an EPR drop will be noted

when the system is turned on. This will require re-

setting power to 0.045 below the computed TRT EPR.

TAKE-OFF RATED THRUST (TRT).

Take-off Rated Thrust (TRT) EPR Setting Charts for

air-conditioning-pressurization on and off are shown

in figures 2-1 and 2-2, respectively. If an engine does

not reach charted TRT-EPR setting, it is not producing

rated thrust. Once the charted take-off rated thrust

EPR is set, no further adjustment to the throttles should

be made during the take-off roll except to avoidexceeding EGT or RPM limits. An EPR drop of

approximately 0.02 may be noted due to ram effect

as the aircraft accelerates.

REDUCED THRUST TAKE-OFF.

When maximum aircraft capability is not required,

take-off and climbout should be accomplished with

reduced engine thrust. The purpose of this procedure

is to minimize engine wear.

NOTE

Do not apply bleed penalties when computing

reduced thrust take-off.

MINIMUM REDUCED THRUST TAKE-OFF EPR.

The minimum reduced thrust take-off EPR is charted

TRT, less 0.15 but never less than 1.60. Determine

from figure 2-1. Once the Reduced Thrust Take-Off

EPR has been established, it shall be used to obtain

thrust factor and take-off factor.

TAKE-OFF EPR.

Take-off EPR is the power setting selected for take-

off (ie. TRT, Reduced EPR)

GO-AROUND.

Maximum EPR values are depicted in figure 2-3 for

go-around. The maximum EPR values based on runway

OAT and pressure altitude are valid for approach

airspeeds. Go-around EPR is non-static TRT. Thrust

factors for take-off must be based on take-off EPR.Thrust factor for landing and emergency return must

be based on go-around EPR.

REVERSE THRUST SETTING.

Thrust reverse limiter settings are shown in figure 2-4.

LOW SPEED COMPRESSOR RPM.

Low speed compressor RPM versus EPR is depicted

on figure 2-5. These values are valid for static

Take-off EPR power settings and are an indirect

measure of thrust.


31/333

2-3

TO 1C-141B-1-1

Figure 2-1.

MODEL: C-141BTF33-P7 ENGINES

DATE: OCTOBER 1968DATA BASIS:C-141A CATEGORY IIFLIGHT TEST

TAKE-OFF RATED THRUST,EPR SETTING

AIR CONDITIONING PRESSURIZATION ON

1. Static thrust.2. Reduce EPR setting by: Rain removal on 0.014 Engine anti-ice on 0.015

3. If wing anti-ice is required after lift-off, reset the EPR to

0.045 below the computed TRT EPR. Do not use wing anti-ice prior to lift-off.

2.2

2.1

2.0

1.9

1.8

1.7

1.6-60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60

1

2

3

4 & ABOVE

PRESS. ALT - 1,000 FT

SL

ENGINEPRESSURERATIO(EPR)

RUNWAY AMBIENT TEMPERATURE - C

NOTE

-1


32/333

TO 1C-141B-1-1

2-4

Figure 2-2.



TAKE-OFF RATED THRUST,EPR SETTING

AIR CONDITIONING PRESSURIZATION OFF

1. Static thrust.

2. Reduce EPR setting by:

Rain removal on 0.027

Engine anti-ice on 0.015

3. If wing anti-ice is required

after lift-off, reset the EPR to

0.045 below the computed TRT

EPR. Do not use wing anti-ice

prior to lift-off.

2.2

2.1

2.0

1.9

1.8

1.7

1.6-60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60

-1

1

2

3

4 & ABOVE


SL

ENGINEPRESSURERA

TIO(EPR)


NOTE


33/333

2-5

TO 1C-141B-1-1

Figure 2-3.

NOTE



GO-AROUNDEPR SETTING

AIR CONDITIONING PRESSURIZATION ON

Four or three engines operating:

Rain removal on 0.009

Engine anti-ice on 0.013

Wing anti-ice on 0.045 (for three

engine operation, open the wing

isolation valve).

2.2

2.1

2.0

1.9

1.8

1.7

1.6-60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60

-1

1

2

3

4 & ABOVE


SL

ENGINEPRESSURERATIO

(EPR)



34/333

TO 1C-141B-1-1

2-6



THRUST REVERSE LIMITERSETTING

12

11

10

9

8

7

6

5

4

3

2

1

0-60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60

LIMITER

SETTING-INDEXNUMBER


5

4

2

1

SL

3

-1

6

5

4

21 SL

3

-1

6

PRESSURE RATIO LIMITED

PRESSUREALTITUDE1,000 FT

Figure 2-4.


35/333

102

100

98

96

94

92

90

88

86

84

82

80

78

1.6 1.7 1.8 1.9 2.0 2.1 2.2

LOWS

PEED

COMPRESSORRPM-

PERCENTN

TAKE-OFF EPR

1

40

RUNW

AYAM

BIEN

TTEM

PERA

TURE

-C

30

20

10

0

-10

-20

-30

-40

MAXIMUM N1

MODEL: C-141BTF33-P7 ENGINES LOW SPEED COMPRESSOR

TAKE-OFF EPR SETTINGSTATIC


Figure 2-5.

2-7/(2-8 blank

TO 1C-141B-1-1


36/333


37/333

3-1

TO 1C-141B-1-1

PART 3. TAKE-OFF AND CLIMB

TABLE OF CONTENTS

Paragraph Page

Conditions Affecting Take-Off Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Basis for Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Take-Off Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Emergency Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Graphic Illustration of the Take-Off Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Maximum Effort Take-Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

Three Engine Ferry Take-Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13

Climbout Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15

Zero Flap Take-Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18

Take-Off Planning Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18

LIST OF CHARTS

Figure Title Page

3-1 Wind Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

3-2 Runway Available Equal to Critical Field Length (Minimum

Recommended Condition) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

3-3 Runway Available Longer Than Crit ical Field

Length (Recommended) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

3-4 Runway Available Less Than Crit ical Field

Length (Not Recommended) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14

3-5 Runway and Crosswind Component - Take-Off Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

3-6 Maximum Crosswind For Take-Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23

3-7 Thrust Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24

3-8 Take-Off Factor - TRT Take-Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25

3-9 Take-Off Factor - Reduced EPR Take-Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27


38/333

TO 1C-141B-1-1

3-2

3-10 RCR Conversion - For Use With Matted Runway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28

3-11 Critical Field Length - 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29

3-12 Maximum Recommended Take-Off Gross Weight - 75 Percent Flaps,

3 Engine Climb Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31

3-13 Climbout Factor - 3 Engines, 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32

3-14 3 ENG COF vs. Climb Gradient (FT/NM) Tabulation Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33

3-15 Climbout Flight Path - 3 Engines, 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34



3-18 Climbout Flight Path - Gradient - 3 Engines, 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

3-19 Maximum Recomended Take-Off Gross Weight - 4 Engines, 75 Percent Flaps . . . . . . . . . . . . . . . 3-38

3-20 4 ENG COF vs. Climb Gradient (FT/NM) Tabulation Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39

3-21 Climbout Factor - 4 Engines, 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40


3-23 Climbout Flight Path Gradient - 4 Engines, 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-42

3-24 Ground Minimum Control Speed - 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43

3-25 Critical Engine Failure Speed and Refusal

Speed - 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-44

3-26 Rotation Speed - 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46

3-27 Maximum Braking Speed - 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47

3-28 Tire Limit Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48

3-29 Air Minimum Control Speed, One Engine Inoperative,

75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-49

3-30 Air Minimum Control Speed - Two Engines Inoperative,

75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50

3-31 Take-Off Ground Run - 4 Engines 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-51

3-32 Take-Off Ground Run - 3 Engines 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-53

LIST OF CHARTS (Continued)

Figure Title Page


39/333

3-3

TO 1C-141B-1-1

LIST OF CHARTS (Continued)

Figure Title Page

3-33 Maximum Recommended Take-off Gross Weight - Two Engine

Climb Performance, 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-55

3-34 Refusal Speed - 75 Percent Flaps, 3 Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-56

3-35 Speed and Distance During Ground Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-58

3-36 Take-Off Stabilizer Setting - 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59

3-37 Minimum Climbout Speed - Minimum Flap Retraction Speed = Minimum

Climbout Speed +25 Knots, 75 Percent Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-60

3-38 Minimum Climbout Speed and Minimum Flap Retraction Speed for

Altitudes above 16,000 Feet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-61

3-39 Critical Field Length - Zero Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-62

3-40 Climbout Factor - 3 Engines, Zero Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-64

3-41 Climbout Flight Path - 3 Engines, Zero Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-65

3-42 Climbout Flight Path - 3 Engines, Zero Flap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-66

3-43 Climbout Flight Path - 3 Engines, Zero Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-67

3-44 Ground Minimum Control Speed - Zero Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-68

3-45 Critical Engine Failure Speed and Refusal Speed - Zero Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-69

3-46 Rotation Speed - Zero Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-71

3-47 Maximum Braking Speed - Zero Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-72

3-48 Take-Off Stabilizer Setting - Zero Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-73

3-49 Minimum Climbout Speed - Zero Flaps, 4 and 3 Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-74


40/333

TO 1C-141B-1-1

3-4

CONDITIONS AFFECTING TAKE-OFFPERFORMANCE.

There are several basic conditions which influence

take-off performance. These conditions assume that the

take-off is made in a normal configuration using the pilot

technique described in TO 1C-141B-1/1C-141C-1, SectionII, NORMAL PROCEDURES. These conditions are as

follows:

1. Aircraf t gross weight

2 . Engine thrust

3 . Temperature

4 . Pressure a lt itude

5. Wind direct ion and veloci ty

6 . Runway slope

7 . Runway surface.

AIRCRAFT GROSS WEIGHT, ENGINE THRUST,AND AIR DENSITY.

The take-off distance for a given gross weight is

affected by engine thrust and air density. Engine thrust

depends upon outside air temperature, pressure altitude,

and operation of systems requiring bleed air.

WIND DIRECTION AND VELOCITY.

Wind direction and velocity can be measured either

at the runway or at the tower. Wind varies with height

above the runway and may be intermittent both indirection and velocity; therefore, caution should always

be exercised in considering the effects of wind on

take-off and climbout performance.

Runway headings are normally given in magnetic

headings. When the wind direction is given as true

heading, apply the local area magnetic variation to

the reported wind direction to obtain an accurate wind

angle from runway.

RUNWAY SLOPE.

An uphill slope reduces acceleration and increases

the distance and time to accelerate to a given speed.

The opposite occurs on a downhill slope. If the distance

is the criteria, as in the case of refusal speed and

critical engine failure speed, the speed increases with

a downhill slope for a given distance. This effect is

considered on the Critical Field Length, Critical Engine

Failure Speed, and Refusal Speed charts.

RUNWAY SURFACE.

The condition of the runway surface will be reported

as a Runway Condition Reading (RCR). The RCR is

a measure of the coefficient of friction between the

tire and the runway surface. All charts involving

stopping distance are based on dry concrete or asphaltfriction coefficients corresponding to an RCR of 23.

Slippery runway surfaces will increase stopping

distances.

When no RCR is available, use the following:

Runway Condition RCR ICAO Designation

Dry 23 Good

Wet 12 Medium

Icy 05 Poor

For operations on all wet, ungrooved runways, use

an RCR of 12. For operations on grooved runways,

use the reported RCR values.

RUNWAY SURFACE COVERING (RSC).

RSC is the average surface covering and is determined

in depth to the nearest 1/10 inch and type as listed

below:

P - Patchy

WR - Wet Runway

SLR - Slush on Runway

LSR - Loose Snow on Runway

PSR - Packed Snow on Runway

IR - Ice on Runway

A typical report of runway condition could be SLR

05P which would indicate slush on runway with an

RCR of 5 and patchy condition.

RSC correction for loose or dry snow is applied to

aircraft performance by dividing the depth of snow

by three for application to the take-off performance

charts.

WARNING

Take-offs will not be attempted with over 1/2

inch of wet snow, slush and/or water, or 3

inches of dry snow on the runway.


41/333

3-5

TO 1C-141B-1-1

BASIS FOR CHARTS.

The take-off performance is based on the pilot technique

described, in NORMAL PROCEDURE, Section II, TO

1C-141B-1/1C-141C-1, and on the designated aircraft

configuration. Normal aircraft take-off configuration

includes the correct flap and stabilizer trim settings.All stopping distances are based on using 75 percent

flap setting, spoilers extended, reverse thrust or no reverse

thrust, and maximum anti-skid braking on dry concrete

or asphalt. A five second period has been allowed for

transition from take-off thrust to maximum braking. This

allows time to recognize the situation, make a decision

to stop, and achieve the braking configuration. The take-

off ground run distances are based on normal take-off

procedure using the stabilizer settings specified for the

flap setting, gross weight, and CG. All take-off and critical

field length distance charts, climb performance charts,

and minimum control speed charts are applicable for

both Reduced EPR Take-off and TRT-EPR Take-off.

TAKE-OFF PLANNING.

Do not use reverse thrust for normal take-off planning.

Use only for max effort take-offs. The 6 brakes portion

of the charts will be used if only 7 or 6 brakes are

available for take-off.

To facilitate take-off planning, an outline summarizing

the procedure to be followed has been included in TAKE-

OFF PLANNING GUIDE. This outline is to be considered

as an aid to take-off planning so that all factors will beconsidered in the correct order, but is not intended as a

substitute for knowledge of the subject. The outline is

entered at the top with the given take-off conditions. The

planning then proceeds along a path through the applicable

branches in either a horizontal or descending manner until

a solution is reached at the bottom of the outline.

REDUCED THRUST TAKE-OFF PROCEDURE.

A Reduced Thrust Take-off should be made when

maximum aircraft capability is not required. The

selected EPR must satisfy the following conditions:

1. The critical field length shall not exceed the

runway length available.

NOTE

Do not apply headwinds when planning a

Reduced Thrust Take-off. Corrections for

tailwinds and gusts shall be applied.

2. The climb gradient with three engines operating

shall equal or exceed the minimum specified value.

3. The climbout flight path shall provide adequate

obstacle and terrain clearance.

NOTE

If the obstacle cannot be cleared at the planned

take-off gross weight using the Reduced Thrust

Take-off EPR, a TRT-EPR Take-off shall be planned.

TRT TAKE-OFF PROCEDURE.

A TRT take-off shall be made when gross weight is

limited by critical field length, obstacle clearance, three-

engine climb, windshear, or gust front from a

thunderstorm or CB is anticipated. Set TRT prior to

brake release when gross weight is limited by critical

field length or obstacle clearance.

RUNWAY AND CROSSWIND COMPONENT.

Normal operations should be limited to operating in

the "Normal Zone" of figure 3-5, and "Maximum

Crosswind" of figure 3-6.

The caution zone and not recommended boundary on

the runway and crosswind component chart for take-off

is established as a result of relatively slow aircraft response

to aileron input during acceleration through

approximately 60 to 80 knots. If the computed crosswind

component is in the "caution zone" and the gross weighis below 207,000 pounds, an increase in gross weigh

with the resulting increase in rotation speed may allow

operation in the "normal zone."

WARNING

If runway is wet or icy, take-off shall not be

made in the "caution zone" of figure 3-5 nor

exceed "Maximum Crosswind for Take-Off" of

figure 3-6. Take-off in the "Not Recommended

Zone" shall not be attempted.

Example Problem.

Given:

1. Runway Heading = 36

2. Wind = 70 degrees/27 knots

3. Gross weight = 169,000 pounds


42/333

TO 1C-141B-1-1

3-6

Find:

1. Runway wind component

2. Crosswind component

3. Is take-off crosswind in the Normal Zone?

Solution:

Use chart on figure 3-5 and read:

1. Runway wind component = 9 knots

2. Crosswind component = 25 knots

3. The computed point is in the Caution Zone.

Increase gross weight to 207,000 pounds in order to

reach the Normal Zone.

THRUST FACTOR AND TAKE-OFF FACTOR.

Any performance losses due to bleed system operation are

accounted for by the reduced EPR used to enter the chart.

NOTE

If wing anti-ice is to be turned on immediately

after lift-off, an additional thrust factor must

be computed for use on the Maximum

Recommended Take-off Gross Weight -

3-Engine Climb Performance, Climbout Factor

and Minimum Climbout Speed charts for TRT

take-offs.

Thrust factors and take-off factors (figures 3-7, 3-8 and

3-9) are reference numbers used on performance charts

to replace temperature and altitude grids.

WIND AND SLOPE.

Definitions.

1 . Steady Wind Reported Steady wind.Value:

2. Gust Incre- Reported wind in excessment: of Steady Wind Value.

3. Light and Winds of 5 knots or less;Variable: will not be applied to per-

formance computations.

4. Variable at Winds reported in excess____ knots: of 5 knots, request pre-

vailing direction and applymost critical computation.

5 . Com ponent : Effective wind parallel oracross the runway.

6. He adwind: Effective wind parallel tothe runway, determinedfrom the Steady WindValue.

7. Tailwind: Effective wind parallel tothe runway, determinedfrom the Steady WindValue plus the GustIncrement.

8 . Crosswind: Effective wind across the

runway, determined fromthe Steady Wind Valueplus the Gust Increment.

9. Calculated: 50 percent of the

headwind component or150 percent of the

tailwind component.

Accounting for Slope.

Consideration for runway slope is provided wherever

pertinent in the chart. Apply slope to applicable take-

off computations.

MAT COVERED RUNWAY.

The take-off performance is not affected when operating

from runways covered with MAT Type AM-2, XM-18B,XM-18C and XM-19, coated with anti-skid material.

However, rejected takeoffs are affected due to the

difference in the braking coefficient. The effect of this

difference is accounted for by using a reduced RCR

value for the MAT runway when calculating critical

field length, ground minimum control speed, critical

engine failure speed and refusal speed. The relationship

between the RCR numbers is presented in figure 3-10.

RUNWAY AVAILABLE (RA).

Runway available is actual runway length less the

aircraft line-up distance. When take-off EPR is set

prior to brake release, subtract 200 feet. When making

a rolling or standing take-off, subtract 400 feet.

ROTATION SPEED (VROT)

Rotation speed is that speed at which rotation from the

three-point attitude to the take-off attitude is initiated.

The take-off planning charts are based on rotation from


43/333

3-7

TO 1C-141B-1-1

Figure 3-1.

three-point attitude to take-off attitude in 2.5 seconds.

Rotation speed may be less than VMCG but never less

than VMCA . Rotation speed is obtained from figure 3-26.

CRITICAL FIELD LENGTH (CFL).

The critical field length is the total length of runwayrequired to accelerate on all engines to critical engine

failure speed, experience an engine failure, then

continue the take-off or stop. It is used during take-

off planning together with the climbout data to

determine the maximum gross weight for a safe take-

off and climbout. For a safe take-off, the critical field

length must be no greater than the length of runway

available. Critical field length is determined fromfigure 3-11.

WIND SUMMARY

RUNWAY COMPONENT

ENTER WIND COMPONENTCHART WITH STEADY WINDVALUE.

RUNWAY COMPONENT

ENTER WIND COMPONENTCHART WITH STEADY WINDVALUE PLUS THE GUSTINCREMENT.

CROSSWIND COMPONENT

ENTER WIND COMPONENTCHART WITH STEADY WINDVALUE PLUS THE GUSTINCREMENT.

GUST INCREMENT

REPORTED WIND INEXCESS OF STEADY WINDVALUE.

APPLY CALCULATED WIND (50% OF COMPONENT) TO TAKE-OFFDISTANCES WHEN NEEDED FOR MAXIMUM EFFORT TAKE-OFFLIMITED BY CRITICAL FIELD LENGTH. APPLY CALCULATED WINDTO LANDING DISTANCES WHEN NEEDED.APPLY 100% OF COMPONENT WHEN COMPUTING MAXIMUMBRAKING SPEED, TIRE LIMIT SPEED, BRAKE LIMITS AND TAKE-OFFGROUND RUN.

DO NOT APPLY HEADWINDS FOR TERRAIN CLEARANCE.

APPLY CALCULATED WIND (150% OF COMPONENT) TO ALL TAKE-OFF AND LANDING DISTANCES.APPLY (100% OF COMPONENT) WHEN COMPUTING MAXIMUMBRAKING SPEED, TIRE LIMIT SPEED, BRAKE LIMITS AND TAKE-OFFGROUND RUN.

APPLY CALCULATED WIND (150% OF COMPONENT) FOR TERRAINCLEARANCE.

ADJUST GROUND MINIMUM CONTROL SPEED FOR 100% OFCOMPONENT.

THE PILOT WILL INCREASE CHARTED ROTATION SPEED ANDAPPROACH SPEED BY THE FULL GUST INCREMENT NOT TO EXCEED10 KNOTS.

HEADWIND

TAILWIND

CROSSWIND

GUSTS

TYPE OF HOW TO OBTAIN

WIND COMPONENT USE OF WIND


44/333

TO 1C-141B-1-1

3-8

Example Problem 1.

Given:

1. Take-off factor = 50.2

2. Gross weight = 296,000 pounds

3. Two engines reverse

4. Slope = 1 percent downhill

5. Wind = 10 knots tailwind calculated

6. Wet runway (0.4 inch water)

7. Partial brakes (6 brakes)

Find:

1. Critical field length

Solution:

1. Use chart on figure 3-11 and read critical field

length = 6,200 feet

Example Problem 2.

Given:

1. Runway available = 6,700 feet

2 . Wet runway

3 . No reverse

4. Wind = 10 knots tailwind calculated

5. Slope = 1.5 percent downhill

6. Take-off factor = 47.5

Find:

1. Maximum brake release gross weight

Solution:

1. Use chart on figure 3-11 and read maximum

brake release gross weight = 301,000 pounds

CRITICAL ENGINE FAILURE SPEED (VCEF)

Critical engine failure speed is that speed to which the

aircraft can be accelerated, lose an engine, and then

continue the take-off or stop in the computed critical

field length. VCE F is used in Take-Off Planning

Computations when "GO" speed is VB(MAX) or 147 KCAS.

REFUSAL SPEED (VR)

Refusal speed is the maximum speed which the aircraft

can attain under normal acceleration and then stop

in the available runway.

NOTE

When CFL and RA are equal, VCEF equals

VR.

MAXIMUM BRAKING SPEED VB(MAX)

Maximum braking speed is the highest speed from

which the aircraft may be brought to a stop without

exceeding the maximum design energy absorption

capability of the brakes.

CAUTION

Exceeding the maximum energy absorption

capability of the brake could result in serious

aircraft damage caused by possible hydraulic

fluid fire and tire explosions.

Maximum braking speed is obtained from figure 3-27.

TIRE PLACARD SPEED.

Tire placard speed is the maximum ground speed that

a tire can withstand during take-off or landing. The

tire placard speed is 174 knots ground speed. This isbased on a sea level standard day, no wind condition.

TIRE LIMIT SPEED.

To convert tire placard speed to tire limit speed KCAS

for conditions other than sea level, standard day with

no wind, see figure 3-28. Use runway wind component

when computing tire limit speed. Tire limit speed

must be equal to or greater than VROT .

GROUND MINIMUM CONTROL SPEED (VMCG).

With take-off EPR set, ground minimum control speedis the minimum airspeed at which the aircraft, while

on the ground, can lose an outboard engine and maintain

directional control. Ground minimum control speeds

are obtained from figure 3-24. To realize the speeds

given for a dry runway surface, full rudder deflection

and positive nosewheel steering capability are required.

The speeds given for a wet or icy runway surface are

based on no nosewheel steering, and assume that


45/333

3-9

TO 1C-141B-1-1

directional control is maintained by full rudder deflection.

Ground minimum control speed is unaffected by increased

rotation speed, slope, or headwind component.

"GO" SPEED (VGO).

"GO" speed is the speed at which the pilot becomescommitted to continue the take-off. "GO" speed will

be the lowest of.

1. Refusal Speed (VR)

2. Rotat ion speed (VROT)

3. Maximum Braking Speed VB(MAX)

4. 147 KCAS (Maximum Ground Spoiler Speed)

This speed will be determined prior to take-off,

considering the following examples:

1. When VR, VB(MAX) or 147 KCAS is "GO" speed,

it must be equal to or greater than VMCG .

2. When VROTis "GO" speed, VMCGis not a factor.

3 . I f "GO" speed is VROT, an increase in VROTdue

to wind gust (not to exceed 10 knots) will increase

"GO" speed an equal amount not to exceed VR,

VB(MAX) or 147 KCAS.

4 . I f "GO" speed is VB(MAX) or 147 KCAS then

VB(MAX) or 147 KCAS must be equal to or greater

then VMCGand VCEF.

AIR MINIMUM CONTROL SPEED (VMCA).

Air minimum control speed (figure 3-29) is the minimum

speed at which an outboard engine can be lost and

directional control maintained utilizing full rudder

deflection and not more than 5 degrees of bank. VMCA

is a function of gross weight and thrust factor; however,

in the upper weight ranges, generally above 200,000

pounds for one engine out, the stall speed is greater

than VMCA . The two engine out air minimum control

speed chart (figure 3-30) depicts the thrust factor -

speed combination that can be balanced directionally

using full rudder, seven degrees of bank angle and/or

50 percent wheel throw.

TAKE-OFF GROUND RUN.

Take-off ground run is the distance through which the

aircraft must be accelerated to reach take-off point. The

take-off ground run is found from figure 3-31. Chart

distances are based on the rotation speeds given in figure

3-26 and are valid for a dry, wet, or icy runway surface

Increased rotation speed will increase ground run. To

determine increased ground run distance for increased

rotation speed refer to Speed and Distance During Ground

Run Chart, figure 3-35, and applicable text.

Example Problem

Given:

1. Chart rotation speed = 124 knots CAS

2. Zero wind ground run = 4,500 feet

Find:

1. Speed at 1,500 feet prior to take-off.

Solution:

1. Enter chart on figure 3-35 with chart rotation

speed (124 KCAS) and zero wind ground roll (4,500

feet) to establish a normal acceleration line. Re-enter

chart at 3,000 feet to normal acceleration line, and

read CAS = 103.5 knots.

STABILIZER TRIM SETTING.

The correct setting can be obtained from figure 3-36

using brake release gross weight and aircraft CG.

This setting produces a trim condition at V MC O

Stabilizer trim settings do not require adjustment forincreased VROT due to gust.

EMERGENCY RETURN

To be prepared for an emergency landing immediately

after take-off, the emergency return portion of the

PERFORMANCE DATA WORK-SHEET should be

completed based on brake release gross weight.

GRAPHIC ILLUSTRATION OF THE TAKE-OFF PROBLEM.

Figures 3-2, 3-3 and 3-4 illustrate both the acceleration

and stopping portions of the take-off run. They also

amplify the definitions presented in the preceding text

A study of these illustrations along with the following

text will supplement the pilot's knowledge of take-off

performance and will enable the pilot to better

understand the theory behind the decisions that mus

be made before and during the take-off.


46/333

TO 1C-141B-1-1

3-10

GRAPH CONSTRUCTION (Figure 3-2, 3-3 and3-4).

The normal four-engine acceleration curve depicts

the speed-distance acceleration characteristics of the

aircraft. The acceleration is computed from the start

of roll to rotation speed at the end of a four-engineground run. The three-engine acceleration curve shows

the speed-distance relationship from the point of

assumed engine failure to the take-off point. The

maximum effort stop curve is computed from refusal

point to a complete stop at the end of the runway.

This includes a five-second transition from the point

of failure to the point of maximum deceleration forces.

This allows the pilot time to recognize the situation,

make a decision to stop, reduce power, apply brakes,

and apply reverse thrust.

THE THREE TAKE-OFF CASES.

Runway Available Equal to Critical Field Length(Figure 3-2).

When the runway available is equal to the critical

field length and an engine failure occurs at V R, the

distance to continue on three engines just equals the

distance to stop. Note that in this condition VCEFand

VRare the same. VMCG must be equal to or lower than

VR, and VB(MAX) must be equal to or greater than

VRor down-loading would be required.

Runway Available Longer Than Critical Field

Length (Figure 3-3).

With this condition, VR is always higher than VCEF .

This is because VR is based upon runway available

and VCE F is based upon the critical field length

required. Arbitrarily, VMCG is shown less than VR, and

VB(MAX) is shown greater than VR; therefore, VRis

"GO" speed.

Runway Available Less Than Critical FieldLength (Figure 3-4).

If the runway available is less than the critical field

length, the aircraft shall be downloaded.

MAXIMUM EFFORT TAKE-OFF

A maximum effort take-off will determine the maximum

gross weight which can be made using all available

runway, clear all obstacles, and maintain a minimum

climb gradient.

The following blocks on the PERFORMANCE DATA

WORKSHEET will be affected by a maximum effort

take-off. All other computations are computed normally.

1. GW - will be the lowest of (GWCFL), (GW3ENG),

(GWoBST) and (GWSCREEN).

2. Runway Avail - Subtract 200 feet from runwaylength. Take-off power will be set prior to brake release.

3 . TRT - TRT wi th a ir condit ioning and

pressurization off.

4. Red EPR/MIN - Not used.

5. GW (CFL) - Gross weight limited by critical field

length will be computed using figure 3-11. Enter this

chart using runway available working backwards through

the correction grids on sheet (2 of 2). Then use TOF

and corrections from sheet (2 of 2) to determine GW.

Use the following correction grids from right to left.

a. RSC.

b. RCR - Use 2 eng rev lines.

c. No. of brakes - Only if 7 or 6 brakes.

d. Wind Comp - Use calculated headwind or

tailwind (Refer to WIND SUMMARY, figure 3-1).

e. Slope - Use up or down.

f. Eng Rev - Use 2 eng rev (Refer to page 3-5

TAKE-OFF PLANNING).

g. Spoilers - Use if applicable.

6. GW (3ENG) - Figure 3-12, use 2.5 climb

gradient unless otherwise directed.

7 . There a re four a reas to cons ider when

determining the maximum allowable gross weight for

obstacle clearance and/or ATC climb restrictions. These

four areas are:

GW (DER Screen Height)-Gross Weight Limited by

Departure End of Runway (DER) Crossing Height

Restrictions

3 Eng (CL Grad)-Three-Engine Climb Gradient

4 Eng (CL Grad)-Four-Engine Climb Gradient

GW (OBST)-Gross Weight Limited by an Obstacle


47/333

3-11

TO 1C-141B-1-1

In the first area, GW (DER screen height), calculations

are made to ensure the aircraft will meet any minimum

height restrictions when crossing the end of the

departure runway. In the second and third areas (three-

engine climb gradient, four-engine climb gradient)

calculations are made to ensure the aircraft can meet

three and four engine published climb gradientrestrictions caused by obstacle and/or ATC climb

restrictions. In the fourth area (maximum gross weight

limited by an obstacle) calculations are made to

determine if a known obstacle can be cleared on three

engines when no published climb gradient restrictions

exist or are not available.

The following procedures are to be used to determine

MAXIMUM GROSS WEIGHT LIMITED BY AN

OBSTACLE OR CLIMB RESTRICTIONS:

a. Gross Weight Limited Departure End of

Runway (DER) crossing height restrictions

NOTE

The DER crossing height restriction is also

referred to as Screen Height.

A departure end of runway crossing height restriction

is a minimum height in feet above the end of the

runways pavement that an aircraft is expected to be

during the take-off . Screen heights wil l vary

depending on the agency/country that surveys the

f ield and is publ ished in approved departure

publications. The screen height is the baseline usedto determine if an obstacle(s) is a factor on the

departure and climbout flight path from a specific

runway. To determine whether a specific DER screen

height restriction can be met, we must first compute

what the aircrafts height will be at the end of the

runway. To do this we subtract the aircrafts computed

Cri t ical Field Length (CFL) from the Runway

Available (RA). This will leave us with a distance

remaining to the end of the runway. This distance is

then multiplied by the minimum climb gradient of

the C-141 of 2.5%. This number, in feet, represents

the aircrafts height in the air when crossing the end

of the runway.

(RA-CFL) x 2.5% = DER Height

This DER Height number is then compared to the DER

screen height restriction to ensure it is equal to or

greater than the restriction (DER Height > Screen

Height). See the following examples:

Example Problem 1:

Given:

(1) DER Crossing Height Restriction = 16 Fee

(From the SID).

(2) RA = 8,000 Feet (From performance dataworksheet).

(3) CFL = 6,600 Feet (From performance data

worksheet).

Find:

(1) The height of aircraft at the end of the runway

(DER Height).

(2) If the aircraft is above the screen heigh

restriction.

Solution:

(1) DER Height is = 35 feet

(8,000 - 6,600 = 1,400) 1,400 x 2.5% = 35

(2) The aircraft is above the DER screen height

restriction.

35 feet 16 feet

In example 1, since the aircraft will be 35 feet in the

air when it reaches the DER, it will be above the required

DER Screen Height of 16 feet. The aircraft thereforeexceeds the published DER Screen Height restriction

on three engines by a minimum of 19 feet.

Example Problem 2:

Given:

(1) DER Crossing Height Restriction = 50 Fee

(From the SID).

(2) RA = 9,000 Feet (From performance data

worksheet).

(3) CFL = 7,300 Feet (From performance data

worksheet).

Find:

(1) DER Height.

(2) If the aircraft is above the screen heigh

restriction.


48/333

TO 1C-141B-1-1

3-12

Solution:

(1) DER Height is = 42 feet

(9,000 - 7,300 = 1,700) 1,700 x 2.5% = 42.5

(round down - use 42 feet)

(2) The aircraft is NOT above the screen height

restriction.

42 feet is not 50 feet

In example 2, since the aircraft will only be 42 feet

in the air when it reaches the DER, it will not meet

the required DER Screen Height of 50 feet. The aircraft

therefore does not meet the published DER Screen

Height restriction on three engines. The aircrafts gross

weight, power settings, runway selection or

atmospheric conditions must change to enable a take-

off that meets the restrictions.

NOTE

If the RA exceeds the aircrafts CFL by 1,400

feet or more, the aircraft will cross the DER

on three engines at or above a 35 foot screen

height restriction for a 2.5% climb gradient:

Gross Weight Limited by DER Screen Height. In case

where the aircaft does not meet the published DER

Screen Height restriction on three engines, use the

following procedure to determine a gross weight to

meet the DER Screen Height restriction.

To determine a GW (Screen Height) we must first

determine the CFL required to meet the DER Screen

Height restriction. Divide the DER Screen Height by

the minimum climb gradient of 2.5%. This will be

the distance required to make a 2.5% climb gradient.

DER Screen Height = Screen Height Distance

2.5%

Example:

50 feet = 2,000 feet2.5%

Second, subract this distance from RA to determine a

new CFL based on the DER Screen Height.

RA - Screen Height Distance = CFL (Screen

Height)

Example:

9,000 2,000 = 7,000 feet

In this case we need to have a CFL no greater than

7,000 feet to meet the DER Screen Height restriction.

Enter the CFL chart backwards using the directions

for GW (CFL), step 5, using this new CFL (Screen

Height) of 7,000 feet. Correct this CFL for conditions

that will affect the take-off only (i.e. RSC, Calculated

Headwind, and up hill slope), not the stopping distance.

This will then give you a gross weight that will ensure

the aircraft meets the DER Screen Height restrictions.

8. GW (OBS) - Gross Weight Limited by an

Obstacle.

The following porcedures are to be used to determine

MAXIMUM GROSS WEIGHT LIMITED BY AN

OBSTACLE.

a . Determine EFFECTIVE OBSTACLE

DISTANCES:

(1) Find TOTAL OBSTACLE DISTANCE

from brake release by adding RUNWAY AVAILABLE

to the OBSTACLE DISTANCE from the departure end

of the runway.

(2) Determine TOTAL OBSTACLE HEIGHT

(AGL) by subtracting FIELD ELEVATION (MSL) from

OBSTACLE HEIGHT (MSL).

(3) Enter figure 3-15 or figure 3-16 with

TOTAL OBSTACLE DISTANCE (STEP 1), TOTAL

OBSTACLE HEIGHT (STEP 2), and determine

CLIMBOUT FACTOR. Use CALCULATED TAILWIND

(4) Enter figure 3-13 with CLIMBOUT

FACTOR and THRUST FACTOR and compute

APPROXIMATE GROSS WEIGHT. If there is no slope

and RSC, this is the GW limited by obstacle.

(5) Enter figure 3-11 with TAKE-OFF

FACTOR and APPROXIMATE GROSS WEIGHT.

Determine the difference between UNCORRECTED

CFL and CFL CORRECTED FOR UPHILL SLOPE and

RSC (only). This is the RSC and SLOPE DISTANCE

CORRECTION.

(6) Subtract the RSC and SLOPE DISTANCE

CORRECTION from TOTAL OBSTACLE DISTANCE

(STEP 1) to find EFFECTIVE OBSTACLE DISTANCE.


49/333

3-13

TO 1C-141B-1-1

b . De te r mi ne EFFECTI VE OBSTACLE

HEIGHT.

(1) Use appropriate formula to find runway

SLOPE CORRECTION. CFL in the formula will be

determined using

Documents

C141 Performance Data