Flex/Derate, Engine Bump and Derated climb

Related issues

Operational Liaison Meeting – Fly-By-Wire aircraft 2004

Customer Services

Flex/Derate comparison, Engine Bump and Derated climb Page 2© A

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MAIN

•FLEX TAKEOFF / DERATED TAKEOFF•BUMP•DERATED CLIMB

Flex/Derate comparison, Engine Bump and Derated climb Page 3© A

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Max TOW

Actual TOW

AvailableThrust

NeededThrust

Flat rated Thrust

Tref

Weight Thrust

EGT Limit

OATFlex Temp T Flex maxOAT

MAXIMUMTHRUST

REDUCTION

Flexible Thrust Takeoff

Conditions of application:•TREF < Tflex, •Today’s OAT < Tflex•Tflex < Tflex max

This reduction level depends on A/C model

Flex/Derate comparison, Engine Bump and Derated climb Page 4© A

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TOGAThrust

FlexibleThrust

Flat rated Thrust

Tref

Thrust

EGT Limit

TemperatureFlex TempOAT

Flexible Takeoff procedure: at any moment, pilot can recover TOGA

Flexible Thrust Takeoff

VMC certified for TOGA thrustVMC certified for TOGA thrust

Flex/Derate comparison, Engine Bump and Derated climb Page 5© A

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Derated Thrust Takeoff

engineengineengine

engineengine

Certified Certified Certified Certified Certified

Let’s have a look to the charts ...

Each derate level is certified and is associated to a new set of performance data

Flex/Derate comparison, Engine Bump and Derated climb Page 6© A

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For the A340-500/600, two new derate levels have been

added: 32% and 40%

Flex/Derate comparison, Engine Bump and Derated climb Page 7© A

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Derated Thrust Take-off on short and contaminated runways

3900 m

+32.9 tons3500 m

+83.2 tons

Flex/Derate comparison, Engine Bump and Derated climb Page 8© A

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DeratedThrust

TOGA RatingTOGA Rating

Thrust

OATOAT

Derated Takeoff procedure: pilot cannot recover TOGA.

Derated RatingDerated Rating

Derated Thrust Takeoff

Thrust for VMC computation at DERATED TO ratingThrust for VMC computation at DERATED TO rating

Flex/Derate comparison, Engine Bump and Derated climb Page 9© A

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TOGA : VMCG = 105 ktsDERATE : VMCG = 100 kts

Flex/Derate comparison, Engine Bump and Derated climb Page 10© A

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TOGA : VMCG = 105 kts

DO NOT USE THESE FIGURES AS A REFERENCE

DERATE : VMCG = 100 kts

Flex/Derate comparison, Engine Bump and Derated climb Page 11© A

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ECAM Message

Let’s see how ...

The aircraft protects the crew against MCDU typing errors during cockpit preparation

Therefore the use of TOGA together with a set of V1/Vr/V2 for DERATE takeoff must be prevented

Flex/Derate comparison, Engine Bump and Derated climb Page 12© A

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ECAM Message

• Let’s assume that no FLEX/DERATE level has been entered into the FMS

• The thrust level is set to FLX/MCT at takeoff…

IMPORTANT:

This message depends on whether the DERATED TAKEOFF option is

installed and available on the aircraft

IMPORTANT:

This message depends on whether the DERATED TAKEOFF option is

installed and available on the aircraft

But…

A warning message appears on the ECAM

Flex/Derate comparison, Engine Bump and Derated climb Page 13© A

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ECAM Message

• For aircraft without the DERATED TAKOFF option on board:

The message request the pilot to set TOGA

Even if FLEX takeoff was envisaged by the pilot, TOGA is proposed when the FLEX information is missing in

the FMS

Flex/Derate comparison, Engine Bump and Derated climb Page 14© A

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ECAM Message

• For aircraft with the DERATED TAKOFF option on board:

The message requests that the pilot sets IDLE

CONCLUSION:For those fleets where both options coexist,

additional pilot briefing may be required.

CONCLUSION:For those fleets where both options coexist,

additional pilot briefing may be required.

In this case, the risk of performing a TOGA takeoff with DERATE takeoff speeds exists,

the takeoff must be aborted

Flex/Derate comparison, Engine Bump and Derated climb Page 15© A

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Max TOW

Actual TOW

AvailableThrust

NeededThrust

Flat rated Thrust

Tref

Weight Thrust

EGT Limit

OATFlex Temp T Flex maxOAT

MAXIMUMTHRUST

REDUCTION

Reduced Thrust Level

Conditions of application:•TREF < Tflex, •Today’s OAT < Tflex•Tflex < Tflex max

Let’s have a look at these reduction levels more in detail ...

Flex/Derate comparison, Engine Bump and Derated climb Page 16© A

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Reduced Thrust Level

ACTUAL SITUATION:

• A318/319/320/321 25% (Flex only)

• A330-200/300 25%

• A340-200/300 25%

• A340-500/600 40%

AVAILABILITY DATE

Upon Request from MID 2004

Upon Request from MID 2004

Upon Request from MID 2004

Under evaluation

PLANNED EVOLUTIONS

• A319-200/300 25% (24% Derate)

• A320-200/300 25% (24% Derate)

• A321-200/300 25% (24% Derate)

• A330-200/300 40%

Tref Tflex max

THRUST

% TOGA

Flex/Derate comparison, Engine Bump and Derated climb Page 17© A

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Transition to CLIMB THRUST

• At high levels of DERATE, the TAKEOFF THRUST may fall below the CLB THRUST

• An increase of thrust must be avoided when pulling the lever to the CLB detent

• An automatic transition sequence to MAX CLB has been implemented for the different engine models

LET’S SEE HOW THIS WORKS….LET’S SEE HOW THIS WORKS….

Flex/Derate comparison, Engine Bump and Derated climb Page 18© A

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Transition to CLIMB THRUST

TRENT 500 : CLIMB ADJUSTEMENT

EPR

Time Thrust Lever

Position

CLIMB

FLEX/DERATE

FLX/MCT CLB

THRST RED ALT

20 s

FROZEN WASHOUT

40 s

• No unexpected thrust increase• Climb performance unchanged• No unexpected thrust increase• Climb performance unchanged

Flex/Derate comparison, Engine Bump and Derated climb Page 19© A

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Transition to CLIMB THRUST

Max Takeoff

Throttle in FLX detent Throttle in CL detent

0.30 0.35 (CFM)0.40 (IAE)

Basic MCL

Mach

Thrust

Number

Max Takeoff - 25%

A319:

Reduced thrust LOW DERATE

Reduced thrust LOW MACH MAX CLIMB LOGIC

Low Mach Max Climb Logic

• On A320 and A321, the current Max Climb rating provides sufficient room for 25 % thrust reduction.

• For future evolutions, similar solutions will be applied (25%→40% for A330)

Flex/Derate comparison, Engine Bump and Derated climb Page 20© A

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MAIN

•FLEX TAKEOFF / DERATED TAKEOFF•BUMP•DERATED CLIMB

Flex/Derate comparison, Engine Bump and Derated climb Page 21© A

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Bump

• The bump is an increased takeoff thrust .

• The bump can be occasionally used when the basic maximum takeoff thrust does not provide the required performance.

• There is no possibility to set an intermediate thrust between the basic maximum takeoff thrust and the bump

Flex/Derate comparison, Engine Bump and Derated climb Page 22© A

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Bump

• Various bumps were defined for the early A320 models, as a function of the customers requirements.

• For the latest A320 family models, the bump can be made available on the following models:4A321-2114A321-2314A320-2144A320-233

AA321A

AA3210

Flex/Derate comparison, Engine Bump and Derated climb Page 23© A

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Bump

• These bumps provide between 6 and 10% more thrust than the basic one.

• They are available only with specific FADEC standards:4IAE engines: SCN184CFM engines: 5BL

• These bumps are available, but not yet certified as no customer has ordered this option yet.

• A lead time of about 9 months will be necessary once we get a customer order

Flex/Derate comparison, Engine Bump and Derated climb Page 24© A

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Bump

• Long range aircraft:4 A340:Presently, a bump is available only for the A340-313 gross weight.

4A330:A bump will be certified mid-2004 on the A330-202. It will provide the thrust of the CF6-80E1A3.

Flex/Derate comparison, Engine Bump and Derated climb Page 25© A

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Bump

• Bump activation:The bump is activated by two guarded pushbuttons, placed on the thrust levers on the A320 Family and on the external thrust levers on the A340.

It can be used with all engines operating and remains active in case of one engine failure.

GUAREGGU

GUARDED PUSHBUTTONS

GUARDED PUSHBUTTONS

Flex/Derate comparison, Engine Bump and Derated climb Page 26© A

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MAIN

•FLEX TAKEOFF / DERATED TAKEOFF•BUMP•DERATED CLIMB

Flex/Derate comparison, Engine Bump and Derated climb Page 27© A

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Principle of thrust reduction

When the MAX CLB thrust is not necessary during the CLIMB phase, it can be performed with less thrust.

• It applies to the climb phase, so its use is completely independent of that of the DERATED TO

• Benefits of thrust reduction4save the engine life (à engine stress)4reduce maintenance costs

THRST RED ALT

TOC

Flex/Derate comparison, Engine Bump and Derated climb Page 28© A

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Derated Climb concept

• Two levels of derated climb available through MCDU• Implementation: EPR/N1 decrement applied on MCL

EPR/N1 • Decrement is function of pressure altitude, delta ISA and

engine bleed configuration.• Result:

4less severe engine operations and resulting lower engine DMC,

4slightly increased climb fuel/time to reach the same flight level.

• The DERATED CLIMB is basic in the LR family since 1997• This option is not available in the SA family

Flex/Derate comparison, Engine Bump and Derated climb Page 29© A

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Engine strain reduction

A340-600 RR Trent 500 Derated climb / Max climb washout function

-20

-15

-10

-5

0

5

0 10000 20000 30000 40000Altitude (ft)

Clim

b th

rust

der

ate

Max climb

ISA+10°C and below

ISA+20°CISA+30°CISA+40°C

D1

D2

In order to maintain the same climb capabilities, the Derated Climb features a Washout function:

Flex/Derate comparison, Engine Bump and Derated climb Page 30© A

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• Example:4A340-642 / Trent 5564Initial weight 372t4ISA4climb law 250kt/320kt/.82 to FL330

MTOW

Derated climb operational effect

MTOW

Time to TOCDCL1: +6min

DCL2: +10min

Time to TOCDCL1: +6min

DCL2: +10min

Distance to TOCDCL1: +40nmDCL2: +64nm

Distance to TOCDCL1: +40nmDCL2: +64nm

Fuel (const dist)DCL1: +89kg

DCL2: +184kg

Fuel (const dist)DCL1: +89kg

DCL2: +184kg

Flex/Derate comparison, Engine Bump and Derated climb Page 31© A

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• AIRBUS proposes a method to determine which level of climb thrust is required to guarantee the same climb capability as when at MTOW with MAX CLB THRUST

REFERENCE MAX STRUCTURAL WEIGHT 250/320/M0.82 MAX CLB

290000

300000

310000

320000

330000

340000

350000

15000 20000 25000 30000 35000 40000

INITIAL CRUISE ALTITUDE (ft)

ISOTIME WEIGHT (Kg)

DCL 1DCL 2

AIRBUS Derated Climb Recommendations

EXAMPLE: TOC = FL330

FL330

Identically TOW=336.3 tons at DCL1 provides the same climb time to TOC as Max Structural Weight at MAX CLB

The TOW=320.5 tons at DCL2provides the same climb time to TOC as Max Structural Weight at MAX CLB

DCL2DCL2DCL2

DCL1DCL1DCL1

MCLBMCLBMCLB

Flex/Derate comparison, Engine Bump and Derated climb Page 32© A

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This document and all information contained herein is the sole property of AIRBUS S.A.S. No intellectual property rights are granted by the delivery of this document or the disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of AIRBUS S.A.S. This document and its content shall not be used for any purpose other than that for which it is supplied.

The statements made herein do not constitute an offer. They are based on the mentioned assumptions and are expressed in good faith. Where the supporting grounds for these statements are not shown, AIRBUS S.A.S. will be pleased to explain the basis thereof.

AN EADS JOINT COMPANYWITH BAE SYSTEMS