DERATE TAKE OFF( ASSUMED TEMPERATURE METHOD )

THE POWER OF FLIGHT

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THE POWER OF FLIGHT

REDUCE TAKE OFF THRUST

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When REAL GW < MAX LIMITING GW Max Thrust is not any more necessary!

THE POWER OF FLIGHT

WHY REDUCE TAKE OFF THRUST ?

You will improve flight safety You will reduce Takeoff EGT Substantial costs may be saved by extension of engine parts life time.3 RXCF 04/02/2006

You will improve flight safety

THE POWER OF FLIGHT

REDUCE TAKE OFF THRUST

IMPROVE ENGINE INTEGRITY BY REDUCTION OF ENGINE DETERIORATION.

PROBABILITY OF ENGINE FAILURE

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You will reduce Takeoff EGT

TAKE OFF IMPACT Vs FLIGHT COST1 0.8 0.6 T/O

THE POWER OF FLIGHT

% of cost 0.4 CLIMB 0.2 CRUISE 0 0.5 1 2 1.5 Flight Leg 2.5 35 RXCF 04/02/2006

Substantial costs may be saved by extension of engine parts life time.

THE POWER OF FLIGHT

EGT MARGIN WILL DECREASE SLOWLY

KEEP SFC AT LOW RATE

TOTAL ENGINE PERFORMANCE RETENTION WILL BE BETTER

LONGER ENGINE LIFE AND INCREMENT OF SHOP VISIT RATE

REDUCTION OF MAINTENANCE COSTS ( material, man power, services ... )6 RXCF 04/02/2006

For

(Length, Altitude, slope) TEMPERATURE, QNH, wind, FLAPS SETTING OBSTACLES HEIGHT & DISTANCE AIRPLANE CONDITION RUNWAY CONDITION MAX

RUNWAY

THE POWER OF FLIGHT

At

TAKEOFF THRUST SETTING

Theres

1 LIMITING GW

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IF REAL GW < MAX LIMITING GW A T called assumed T can be computed that would limit the performance of the airplane to the real GW.T/Off GW Flat Rated T THRUSTTHE POWER OF FLIGHT

Today Max Thrust Today Reduced Thrust

Today Max GW Today Real GW

Real T Assumed T8 RXCF

T

04/02/2006

HOUSTON, We've got a problem here! It looks like the assume temperature we took: 55 wasnt the right one ! Could you confirm ?!?

THE POWER OF FLIGHT

?!?

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The accuracy of the OAT is essential to optimize :

THE POWER OF FLIGHT

TAKEOFF GROSS WEIGHT

ASSUMED TEMPERATURE

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DOES THE ASSUMED TEMPERATURE METHOD ALWAYS CONSERVATIVE ?

THE POWER OF FLIGHT

YES, because of T effect on performance.Example: Assumed T = 45 & V1 CAS = 140 Kts TAS = 148.5 Kts

The Speed used to comply with the performance calculations!

The Speed you will have... Air T = 10 & V1 CAS = 140 KtsRXCF

TAS = 138.5 Kts11 04/02/2006

TAS = CAS +/- 1%+ if T > Std - if T < Std

5c / Std

THE POWER OF FLIGHT

Since the V1 are the same for both: The actual T & The assumed T The acceleration distances to V1 are always less because the True Airspeed values are always lower.12 RXCF 04/02/2006

AIRCRAFT PERFORMANCE MARGIN WITH REDUCED TAKEOFF THRUST IS ALWAYS CONSERVATIVE.

THE POWER OF FLIGHT

V1 CAS = 140 Kts V1 TAS = 148.5 Kts

V1 CAS = 140 Kts V1 TAS = 138.5 Kts

Air T = 10c

Air T = 45c

Distance from start of roll13 RXCF 04/02/2006

AIRCRAFT PERFORMANCE MARGIN WITH REDUCED TAKEOFF THRUST IS ALWAYS CONSERVATIVE. You compute at T = 45 but You fly at T = 10

THE POWER OF FLIGHT

V1 CAS = 140 Kts

V1 TAS = 138.5 Kts V1 TAS = 148.5 Kts

ir T A

c 10 =

T A ir

c 45 =

Distance from start of roll14 RXCF 04/02/2006

TAKE OFF DATA ASSOCIATED WITH A PARTICULAR AMBIENT TEMPERATURE IS ALWAYS CONSERVATIVE FOR ANY LOWER TEMPERATURE WITHIN THRUST REDUCTION LIMIT.

THE POWER OF FLIGHT

You know what ?

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THE POWER OF FLIGHT

AIRLINE IS FULLY INVOLVED FOR ENGINE CHOICE CREWS ARE THE MAIN CONTRIBUTORS FOR SAVING THE ENGINE !

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THE POWER OF FLIGHT

TH E E NDTHANKS FOR YOUR ATTENTION !

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