range of v1 - smartcockpit · range of v1range of v1 range of v1. 3 “pilot’s” definition of...

Range of V1Range of V1Performance Engineer OperationsFlight Operations EngineeringPerformance Engineer OperationsFlight Operations Engineering

November 2001November 2001

Range of V1Range of V1

Range of V1. 2

What is V1?What is V1?

V1 is the speed at which the takeoff should be continued unless the stopping maneuver has already been initiated

V1 is the speed at which the takeoff should be continued unless the stopping maneuver has already been initiated


Range of V1. 3

“Pilot’s” definition of V1“Pilot’s” definition of V1V1 - The speed selected for each takeoff, based

upon approved performance data and specified conditions, which represents:

V1 - The speed selected for each takeoff, based upon approved performance data and specified conditions, which represents:• The maximum speed by which a rejected takeoff must be initiated to assure that a safe stop can be completed withintheremaining runway, or runway and stopway;

• The maximum speed by which a rejected takeoff must be initiated to assure that a safe stop can be completed withintheremaining runway, or runway and stopway;

•The minimum speed which assures that a takeoff can be safely completed within the remaining runway, or runway and clearway, after failure of the most critical engine at a designated speed; and

•The minimum speed which assures that a takeoff can be safely completed within the remaining runway, or runway and clearway, after failure of the most critical engine at a designated speed; and

(AC 120-62)(AC 120-62)

• The single speed which permits a successful stop or continued takeoff when operating at the minimum allowable field length for a particular weight.

• The single speed which permits a successful stop or continued takeoff when operating at the minimum allowable field length for a particular weight.


Range of V1. 4


• Definitions• Physical Representation• Graphical Presentation• Available V1 Range• Examples• Reduced V1 Policy



Range of V1. 5

DefinitionsDefinitions

• VEF Engine Failure Speed - The speed at which the critical engine becomes inoperative

• VEF Engine Failure Speed - The speed at which the critical engine becomes inoperative

• VR Rotation Speed - The speed at which the rotation from three point attitude to the takeoff attitude is initiated.

• VR Rotation Speed - The speed at which the rotation from three point attitude to the takeoff attitude is initiated.

• VLOF Lift-off Speed - The speed at which the airplane becomes airborne.

• VLOF Lift-off Speed - The speed at which the airplane becomes airborne.

• V2 Takeoff Safety Speed - The target speed to be attained at the screen height (e.g. 35 ft), assuming one engine inoperative and rotation initiated at VR

• V2 Takeoff Safety Speed - The target speed to be attained at the screen height (e.g. 35 ft), assuming one engine inoperative and rotation initiated at VR


Range of V1. 6

Definitions (cont’d)Definitions (cont’d)

• VMCG Ground Minimum Control Speed - The speed during the takeoff run at which, when the critical engine is suddenly made inoperative, it is possible to maintain directional control of the airplane using rudder alone, without deviating from the runway centerline by more than 30 ft.

• VMCG Ground Minimum Control Speed - The speed during the takeoff run at which, when the critical engine is suddenly made inoperative, it is possible to maintain directional control of the airplane using rudder alone, without deviating from the runway centerline by more than 30 ft.

• VMBE Maximum Brake Energy Speed - The highest speed from which the airplane may be brought to a stop without exceeding the maximum energy absorption capability of the brakes. Maximum Brake Energy Speed is compared in takeoff planning to V1.

• VMBE Maximum Brake Energy Speed - The highest speed from which the airplane may be brought to a stop without exceeding the maximum energy absorption capability of the brakes. Maximum Brake Energy Speed is compared in takeoff planning to V1.


Range of V1. 7

Definitions (cont’d)Definitions (cont’d)

• V1/VR Speed Ratio - The ratio of V1 to the rotation speed VR. Used to generalize data for graphical presentation.

• V1/VR Speed Ratio - The ratio of V1 to the rotation speed VR. Used to generalize data for graphical presentation.

• Standard V1/VR - The V1/VR speed ratio defined by the one engine inoperative field length limited condition. Commonly used in Boeing takeoff analysis software.

• Standard V1/VR - The V1/VR speed ratio defined by the one engine inoperative field length limited condition. Commonly used in Boeing takeoff analysis software.


Range of V1. 8





Range of V1. 9

V1 is selected to ensure:V1 is selected to ensure:

V1 V1

All Engine All Engine

VEF VEF

Engine Inop Engine Inop

- Greater than or equal to VMCG- Greater than or equal to VMCG- Less than or equal to VR- Less than or equal to VR- Less than or equal to VMBE- Less than or equal to VMBE

- Stop on available surface- Stop on available surface

VR VR VLOF VLOF

V2 V2

- Go with engine inoperative- Go with engine inoperative

35 ft 35 ft


Range of V1. 10

FAR takeoff field length is the longer of:FAR takeoff field length is the longer of: Engine Inoperative Accelerate-Go Distance: Engine Inoperative Accelerate-Go Distance:

Brake Release Brake Release

One Engine Inop Acceleration

One Engine Inop Acceleration

All EngineAcceleration

All EngineAcceleration

VEF VEF V1 V1 VR VR VLOF VLOF V2 V2

35 ft 35 ft

X 1.15X 1.15

Accelerate-Stop Distance: Accelerate-Stop Distance:

FULL STOP FULL STOP All Engine

Acceleration All Engine

Acceleration

EVENT EVENT V1 V1 VB VB

BA BA TC TC SP SP


115% All Engine Distance to 35 ft: 115% All Engine Distance to 35 ft:

All Engine Acceleration All Engine Acceleration

VR VR VLOF VLOF V2 V2

35 ft 35 ft



Range of V1. 11

V1 - Distance RelationshipsV1 - Distance Relationships (Constant Gross Weight) (Constant Gross Weight)

V1 V1

35 ft 35 ft Brake Release Brake Release

Stop Stop

Low V1 Low V1


Range of V1. 12


V1 V1


Stop Stop

Mid V1 Mid V1


Range of V1. 13


V1 V1


Stop Stop

High V1 High V1

Note: 115% All Engine Takeoff Distance is not affected by V1 choice Note: 115% All Engine Takeoff Distance is not affected by V1 choice


Range of V1. 14

Why a range of V1?Why a range of V1?

EVEN THOUGH ANY VALUE IN THE ALLOWABLE RANGE OF V1 MEETS REGULATORY REQUIREMENTS, ONLY ONE V1 SHOULD BE SELECTED FOR EACH SCHEDULED TAKEOFF. TO AID IN THIS SELECTION, THE FOLLOWING FACTS SHOULD BE CONSIDERED:

EVEN THOUGH ANY VALUE IN THE ALLOWABLE RANGE OF V1 MEETS REGULATORY REQUIREMENTS, ONLY ONE V1 SHOULD BE SELECTED FOR EACH SCHEDULED TAKEOFF. TO AID IN THIS SELECTION, THE FOLLOWING FACTS SHOULD BE CONSIDERED:


Range of V1. 15

Why a range of V1 ?(cont’d)Why a range of V1 ?(cont’d)

1. The stopping margins are increased for a rejected takeoff. (increased stopping margin is helpful on runways with reduced braking capability)

1. The stopping margins are increased for a rejected takeoff. (increased stopping margin is helpful on runways with reduced braking capability)

WHEN A LOW V1 IS SELECTED: (FOR A CONSTANT GROSS WEIGHT...)

WHEN A LOW V1 IS SELECTED: (FOR A CONSTANT GROSS WEIGHT...)

2. There is additional margin from Brake Energy Limits2. There is additional margin from Brake Energy Limits

3. There may be only the minimum required clearance over the end of the runway if it is necessary to continue the takeoff after an engine failure.

3. There may be only the minimum required clearance over the end of the runway if it is necessary to continue the takeoff after an engine failure.


Range of V1. 16

Why a range of V1 ?(cont’d)Why a range of V1 ?(cont’d)

1. The margins are increased for a continued takeoff. (required takeoff distance is less; V2 is reached at an earlier point)

1. The margins are increased for a continued takeoff. (required takeoff distance is less; V2 is reached at an earlier point)

WHEN A HIGH V1 IS SELECTED: (FOR A CONSTANT GROSS WEIGHT...)

WHEN A HIGH V1 IS SELECTED: (FOR A CONSTANT GROSS WEIGHT...)

2. There is additional margin from Ground Minimum Control Limits

2. There is additional margin from Ground Minimum Control Limits

3. There may be only the minimum required on stopping distance (the entire runway may be required if the takeoff is rejected at V1

3. There may be only the minimum required on stopping distance (the entire runway may be required if the takeoff is rejected at V1


Range of V1. 17





Range of V1. 18

767-300ER / CF6-80C2B6/B6F distances767-300ER / CF6-80C2B6/B6F distances

V1 Accel-Go Accel-Stop V1 Accel-Go Accel-Stop

180000 kg 130 kts 12050 ft 6025 ft 180000 kg 130 kts 12050 ft 6025 ft140 kts 11220 ft 6910 ft140 kts 11220 ft 6910 ft150 kts 10250 ft 7890 ft150 kts 10250 ft 7890 ft



TEMP = 15C ELEV = SEA LEVEL NO WIND NO SLOPE A/C ON FLAPS 5



Range of V1. 19

V1 Effect on Accel-Go and Accel-StopV1 Effect on Accel-Go and Accel-Stop Accel-Go Required

Accel-Go Required

Accel-Stop Require

d

Accel-Stop Require

d

Balanced Field Length

Balanced Field Length V1

(X-Plot)(X-Plot)


Range of V1. 20

V1 Effect on Accel-Go and Accel-StopV1 Effect on Accel-Go and Accel-Stop (“Web” chart)(“Web” chart) Constant Pressure Alt, Temp, Wind, Slope

160t

170t

180t

V1 = 13

0 kts

V1 = 14

0 kts

V1 = 15

0 kts


Range of V1. 21

Runway Length and V1 Adjustments (Web Chart)Runway Length and V1 Adjustments (Web Chart)

CORRECTED ACCELERATE-STOP DISTANCE

ENG

INE

INO

PER

ATIV

EC

OR

REC

TED

TAK

EOFF

DIS

TAN

CE

CORRECTEDCORRECTED

CO

RR

ECTE

DC

OR

REC

TED

Speed

Rati

o, V1/V

R

increasing


Range of V1. 22

Runway Length and V1 Adjustments (Web Chart)Runway Length and V1 Adjustments (Web Chart)


ENG

INE

INO

PER

ATIV

EC

OR

REC

TED

TAK

EOFF

DIS

TAN

CE

Corrected Runway Length

incr

easin

g


Range of V1. 23

Corrected Runway Length:Corrected Runway Length:

One Engine InoperativeCorrected Runway Length(CRL) generalizes:

One Engine InoperativeCorrected Runway Length(CRL) generalizes:

• Temperature• Temperature• Gross Weight• Gross Weight

• Altitude• Altitude


Range of V1. 24

Corrected Runway Length RequiredCorrected Runway Length Required

AIRPORT TEMPERATURE TAKEOFF GROSS WEIGHTLOW HIGH LOW HIGH

CORRECTED RUNWAY LENGTH REQUIRED

LOW

HIGH

LONG

SHORT

AIRPORT PRESSUREALTITUDE

CORRECTEDRUNWAYLENGTH


Range of V1. 25

Engine Inoperative Corrected Takeoff DistanceEngine Inoperative Corrected Takeoff Distance

ACTUAL RUNWAY LENGTH - 1000 M

ENGINE INOPERATIVE CORRECTED TAKEOFF DISTANCE - 1000 M

0 1 2 3 4 5 6 7

ENGINE INOPERATIVECORRECTED TAKEOFF DISTANCE

0 1 2 3 4 5 6 7

CLEARWAY

SLOPE

WIND

ANTI-ICE

-

+

-

+

MAXIMUM ALLLOWABLE CLEARWAY


Range of V1. 26

Corrected Accelerate-Stop DistanceCorrected Accelerate-Stop Distance

ACCELERATE-STOP DISTANCE - 1000 M

CORRECTED ACCELERATE-STOP DISTANCE - 1000 M

0 1 2 3 4 5 6 7


0 1 2 3 4 5 6 7

ANTI-SKID

WIND

-

+

SLOPE-

+

OPERATING

INOP

1 BRAKE DEACT.

ANTI-ICE


Range of V1. 27

Takeoff SpeedsTakeoff Speeds

AIRPORT OAT

TAKEOFF SPEEDS

PRESSURE ALTITUDE

ROTATION SPEED VR TAKEOFF SAFETY SPEED V2

TAKEOFF G

RO

SS WEIG

HT

TAKEOFF G

RO

SS WEIG

HT


Range of V1. 28


Corrected Accelerate-Stop Distance

Engi

ne In

oper

ativ

eC

orre

cted

Tak

eoff

Dis

tanc

e

Engine Inoperative Corrected Takeoff Distance Available

Corrected

Runway Length

Corrected Runway Length Required

RUNWAY LENGTH AND V1 ADJUSTMENTS

Cor

rect

ed A

ccel

-Sto

pD

ista

nce

Ava

ilabl

e


Range of V1. 29



Engi

ne In

oper

ativ

eC

orre

cted

Tak

eoff

Dis

tanc

eCorrected

Runway Length

Standard V1/VR

RUNWAY LENGTH AND V1 ADJUSTMENTS

MaximumV1/VR

MinimumV1/VR


Range of V1. 30

Determining a Range of V1Determining a Range of V1USING THE AFM SECTION 4, PERFORMANCE CHARTSUSING THE AFM SECTION 4, PERFORMANCE CHARTS

1. DETERMINE THE CORRECTED RUNWAY LENGTH REQUIRED FOR THE TAKEOFF GROSS WEIGHT, AIRPORT TEMPERATURE, AND PRESSURE ALTITUDE.

1. DETERMINE THE CORRECTED RUNWAY LENGTH REQUIRED FOR THE TAKEOFF GROSS WEIGHT, AIRPORT TEMPERATURE, AND PRESSURE ALTITUDE.

2. DETERMINE THE ENGINE INOPERATIVE CORRECTED TAKEOFF DISTANCE AVAILABLE.2. DETERMINE THE ENGINE INOPERATIVE CORRECTED TAKEOFF DISTANCE AVAILABLE.

3. DETERMINE THE CORRECTED ACCELERATE-STOP DISTANCE AVAILABLE.3. DETERMINE THE CORRECTED ACCELERATE-STOP DISTANCE AVAILABLE.

4. DETERMINE (V1/VR)MIN FROM THE RUNWAY LENGTH AND V1 ADJUSTMENT (WEB) CHARTUSING THE ENGINE INOPERATIVE CORRECTED TAKEOFF DISTANCE AVAILABLE (FROM 2), AND THE CORRECTED RUNWAY LENGTH REQUIRED (FROM 1).

4. DETERMINE (V1/VR)MIN FROM THE RUNWAY LENGTH AND V1 ADJUSTMENT (WEB) CHARTUSING THE ENGINE INOPERATIVE CORRECTED TAKEOFF DISTANCE AVAILABLE (FROM 2), AND THE CORRECTED RUNWAY LENGTH REQUIRED (FROM 1).

5. DETERMINE (V1/VR)MAX FROM THE WEB CHART USING THE CORRECTED ACCELERATE-STOP DISTANCE AVAILABLE (FROM 3), AND THE CORRECTED RUNWAYLENGTH REQUIRED (FROM 1).

5. DETERMINE (V1/VR)MAX FROM THE WEB CHART USING THE CORRECTED ACCELERATE-STOP DISTANCE AVAILABLE (FROM 3), AND THE CORRECTED RUNWAYLENGTH REQUIRED (FROM 1).

6. DETERMINE ROTATION SPEED VR, FOR THE TAKEOFF GROSS WEIGHT AND AIRPORTTEMPERATURE AND PRESSURE ALTITUDE.

6. DETERMINE ROTATION SPEED VR, FOR THE TAKEOFF GROSS WEIGHT AND AIRPORTTEMPERATURE AND PRESSURE ALTITUDE.

7. DETERMINE V1 MIN AND V1 MAX BY MULTIPLYING THE APPROPRIATE V1/VR RATIOSBY VR.

7. DETERMINE V1 MIN AND V1 MAX BY MULTIPLYING THE APPROPRIATE V1/VR RATIOSBY VR.


Range of V1. 31

Determining a Range of V1:Determining a Range of V1:

NOTE: V1MIN and V1MAX are the lowest and highest values of V1 that will satisfy all the Federal Aviation Regulations related to Maximum Takeoff Gross Weight, Field Length Limits. V1 must not be greater thanVMBE or VR, nor less than VMCG

NOTE: V1MIN and V1MAX are the lowest and highest values of V1 that will satisfy all the Federal Aviation Regulations related to Maximum Takeoff Gross Weight, Field Length Limits. V1 must not be greater thanVMBE or VR, nor less than VMCG


Range of V1. 32

Range of V1 DeterminationRange of V1 Determination

V1MIN V1MIN

Actual Runway Length Actual Runway Length

V1MAX V1MAX

Engine Inoperative Corrected Takeoff Distance Available

Engine Inoperative Corrected Takeoff Distance Available Corrected

Accelerate-Stop Distance Available

Corrected Accelerate-Stop

Distance Available

V1

VR MAX

V1

VR MAX

V1

VR MIN

V1

VR MIN

V1

VR MIN

V1

VR MIN X VR X VR

V1

VR MAX

V1

VR MAX X VR X VR

Rotation Speed Rotation Speed

Takeoff Gross Weight Takeoff Gross Weight



1 1 2 2

3 3

4 4 5 5

6 6

7 7 7 7

Actual Runway Length plus

Stopway

Actual Runway Length plus

Stopway


Range of V1. 33

Actual AFM Charts:Actual AFM Charts:

STOPSTOP

Actual AFM Charts


Range of V1. 34

Example Conditions:Example Conditions:

• 767-300ER / CF6-80C2B4• FLAPS 5• A/C ON• ANTI-ICE OFF• TAKEOFF GROSS WEIGHT = 335,000 LB• AIRPORT PRESSURE ALTITUDE = 5000 FT• AIRPORT TEMPERATURE = 35 DEG C• RUNWAY LENGTH = 10500 FT• SLOPE = -1%• WIND = 11 KTS HEADWIND• NO CLEARWAY OR STOPWAY

• 767-300ER / CF6-80C2B4• FLAPS 5• A/C ON• ANTI-ICE OFF• TAKEOFF GROSS WEIGHT = 335,000 LB• AIRPORT PRESSURE ALTITUDE = 5000 FT• AIRPORT TEMPERATURE = 35 DEG C• RUNWAY LENGTH = 10500 FT• SLOPE = -1%• WIND = 11 KTS HEADWIND• NO CLEARWAY OR STOPWAY

Example Solution


Range of V1. 35

Class Problems:Class Problems:

STOPSTOP

Problem Set


Range of V1. 36

Minimizing V1Minimizing V1

When your dispatch weight is below the maximum allowed, V1 can be reduced while remaining within the takeoff distance allowed

When your dispatch weight is below the maximum allowed, V1 can be reduced while remaining within the takeoff distance allowed

At weights below the maximum takeoff weightAt weights below the maximum takeoff weight


Range of V1. 37


Takeoff Gross Weight

V 1

VMCGVMCG

Takeoff Distance Available


V1 = VRV1 = VR



One Engine InopField Length Limit

Range of V1


Range of V1. 38



Engi

ne In

oper

ativ

eC

orre

cted

Tak

eoff

Dis

tanc

e

V 1= V R

Acc

el-S

top

Dis

tA

vaila

ble

V 1=

V MCG



Range of V1. 39



Engi

ne In

oper

ativ

eC

orre

cted

Tak

eoff

Dis

tanc

e

Range

of V1

One Engine InopField Length Limit


Range of V1. 40


V1 Accel-Go Accel-Stop V1 Accel-Go Accel-Stop







Range of V1. 41

6000

7000

8000

9000

10000

11000

12000

13000

4000 5000 6000 7000 8000 9000 10000

V1 ReductionV1 Reduction

13

0kt

s

14

0 kt

s

15

0 kt

s

16

0 kt

s

160t

180t

170t

Accelerate-Stop Distance - ft

Engi

ne In

oper

ativ

e Ta

keof

f Dis

tanc

e -f

t


Range of V1. 42

6000

7000

8000

9000

10000

11000

12000

13000

4000 5000 6000 7000 8000 9000 10000

Balanced

V1Balanced

V1


160t

130

kts

14

0 kt

s

15

0 kt

s

180t

16

0 kt

s

170t

For a field length of 9000 ft: Field Limit TOW = V1 =

For a field length of 9000 ft: Field Limit TOW = V1 =

180,000kg 160 kts 180,000kg 160 kts


Engi

ne In

oper

ativ

e Ta

keof

f Dis

tanc

e -f

t


Range of V1. 43


Bal V1 Bal V1

F.L. GW = 180t 160 kts 160 kts (CRL = 9000 ft) F.L. GW = 180t 160 kts 160 kts (CRL = 9000 ft)



Minimum V1 for weight


Delta V1 from bal to min


No reduction No reduction

Actual GW = 170t ? ? ? Actual GW = 170t ? ? ?


Range of V1. 44

6000

7000

8000

9000

10000

11000

12000

13000

4000 5000 6000 7000 8000 9000 10000


160t

130

kts

14

0 kt

s

15

0 kt

s

180t

16

0 kt

s

170tBalanced

V1Balanced

V1

For a field length of 9000 ft and Actual TOW = 170,000kg:

For a field length of 9000 ft and Actual TOW = 170,000kg:

Balanced V1 = 154 kts Balanced V1 = 154 kts Minimum V1 = 144 kts Minimum V1 = 144 kts


Engi

ne In

oper

ativ

e Ta

keof

f Dis

tanc

e -f

t


Range of V1. 45


Bal V1 Bal V1

Actual GW = 170t 154 kts 144 kts Actual GW = 170t 154 kts 144 kts







Actual GW = 160t 148 kts 120 kts Actual GW = 160t 148 kts 120 kts

F.L. GW = 170t 154 kts 154 kts No reduction (CRL = 7910 ft) F.L. GW = 170t 154 kts 154 kts No reduction (CRL = 7910 ft) Actual GW = 160t 148 kts 137 kts -11 kts Actual GW = 160t 148 kts 137 kts -11 kts

Actual GW = 150t 141 kts 110 kts -31 kts Actual GW = 150t 141 kts 110 kts -31 kts

F.L. GW = 180t 160 kts 160 kts (CRL = 9000 ft) F.L. GW = 180t 160 kts 160 kts (CRL = 9000 ft)

No reduction No reduction

-10 kts -10 kts

-28 kts -28 kts


Range of V1. 46

Range of V1 - SummaryRange of V1 - Summary

• V1 within the allowable range can be chosen to maximize margins on either Go or Stop

• V1 within the allowable range can be chosen to maximize margins on either Go or Stop

• Statistical evidence from RTO accidents and incidents might lead us to consider a Reduced V1 Policy

• Statistical evidence from RTO accidents and incidents might lead us to consider a Reduced V1 Policy

• Range of V1 can be used to optimize both performance and takeoff safety

• Range of V1 can be used to optimize both performance and takeoff safety

• A single V1 is chosen for each takeoff• A single V1 is chosen for each takeoff

• Within the allowable V1 Range, all Federal Aviation Regulations related to Maximum Takeoff Gross Weight, Field Length Limits, are satisfied.

• Within the allowable V1 Range, all Federal Aviation Regulations related to Maximum Takeoff Gross Weight, Field Length Limits, are satisfied.

Range of V1Range of V1Performance Engineer OperationsFlight Operations EngineeringPerformance Engineer OperationsFlight Operations Engineering

November 2001November 2001 W004d. 47

range of v1 - smartcockpit · range of v1range of v1 range of v1. 3 “pilot’s” definition of...

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