EDE Reduced Thrust TOFF

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Transcript of EDE Reduced Thrust TOFF

Reduced Thrust Takeoff

REDUCED THRUST TAKEOFF

Reduced Thrust Takeoff

Reduced Thrust TakeoffObjective

Principle

Flexible Takeoff

Derated Takeoff

Flex Temperature Calculation

Reduced Thrust Takeoff

Objective To explain the two different ways to reduce thrust during takeoffFlexible takeoff Derated takeoff To compare the two takeoff techniques

Reduced Thrust Takeoff

Reduced Thrust TakeoffObjective

Principle

Flexible Takeoff

Derated Takeoff

Flex Temperature Calculation

weight

Reduced Thrust Takeoff

Principle

weight

weight

Reduced Thrust Takeoff

Principle

weight

You need less Thrust

Reduced Thrust Takeoff

Principle When your Actual Takeoff Weight is lower than the Maximum takeoff Weight, it is possible to perform a takeoff with less than the maximum takeoff thrust. This thrust reduction improves engine life and reduces maintenance costs.

Reduced Thrust Takeoff

Principle Which part of the aircraft is concerned ?engine

aerodynamics

Reduced Thrust Takeoff

Principle Benefits of thrust reduction saves the engine life ( engine stress)

improves engine reliability ( Probability of engine failure) reduces maintenance costs

Two methods are available:

Flexible Takeoff

Derated Takeoff

Reduced Thrust Takeoff

Principle Thrust levers : 5 positions on Airbus aircraft TOGA : Takeoff / Go-Around thrust Maximum thrust available . Limited to 5 min with all engines operative . Limited to 10 min with one engine out MCT : Maximum Continuous Thrust No time limit with one engine out FLX : Flexible T/O Thrust DRT : Derated T/O thrust CL : Max Climb Thrust or Max Cruise Thrust Idle Max reverse

Power

Reduced Thrust Takeoff

Principle Thrust levers : 5 positions on Airbus aircraft TOGA : Takeoff / Go-Around thrust Maximum thrust available . Limited to 5 min with all engines operative . Limited to 10 min with one engine out MCT : Maximum Continuous Thrust No time limit with one engine out FLX : Flexible T/O Thrust DRT : Derated T/O thrust CL : Max Climb Thrust or Max Cruise Thrust Idle Max reverse

Power

Reduced Thrust Takeoff

Reminder about engines and thrustThrust levers TOGA thrust variation with OATThrust

EGT Limit

Tref

OAT

Reduced Thrust Takeoff

TOGA thrust variation with OAT Weight Thrust

EGT Limit

Tref

OAT

Reduced Thrust Takeoff

Reduced Thrust TakeoffObjective

Principle

Flexible Takeoff

Derated Takeoff

Flex Temperature Calculation

Reduced Thrust Takeoff

Principle Flex temperature

Flex Take Off : what for ? To enable takeoff without engines at full rate reduces :

WeightMax TOW

Thrust

the probability of a failure (safety aspect), the engine deterioration rate and associated maintenance costs (economic aspect).Flat rated Thrust

Available ThrustNeeded Thrust

Actual TOW

Flex Take Off : The pilot enters the Flex. Temp. in the MCDU: EGT Limit Setting thrust levers on FLX will provide necessary thrust for takeoff.

OAT

Tref

Flex Temp

OAT

Reduced Thrust Takeoff

Principle Flex temperature

WeightMax TOW

ThrustAvailable ThrustNeeded ThrustFlat rated Thrust EGT Limit

Actual TOW

25 %reduction max

Thrust reduction mustn't exceed 25 %, to quickly recover full available TOGA thrust if necessary. TOGA Thrust (daN)OAT

T Flex max

Tref

Flex Temp

OAT

Reduced Thrust Takeoff Conditions of application: Flex. take off is to be made only if : 1) TREF < Tflex. Flex temperature 2) OAT < Tflex. 3) Tflex Tflex max Weight Thrust Available ThrustFlat rated Thrust EGT Limit Actual TOW

Principle

Max TOW

Needed Thrust

T Flex max

OAT

Tref

Flex Temp

OAT

Reduced Thrust Takeoff

Flex Temperature

ThrustTOGA Thrust Flexible ThrustFlat rated Thrust

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

EGT Limit

OAT

Tref

Flex Temp

OAT

Reduced Thrust Takeoff

Flex Temperature

ThrustVMCG/VMCA based on maximum TOGA thrustEGT Limit

Tref

OAT

Reduced Thrust Takeoff

Conclusion : Which one shall be favored ?

Flexible Takeoff Thrust level is less than TOGA. Performance for a flex T/O is computed by adjusting the max T/O thrust performance (use of a single T/O chart calculated for TOGA). At any moment it is possible to recover TOGA (same minimum control speeds as TOGA). Thrust setting parameters for flex T/O are not considered as T/O operating limits. Flex T/O is forbidden on contaminated runways. No performance improvement.

Reduced Thrust Takeoff

Reduced Thrust TakeoffObjective

Principle

Flexible Takeoff

Derated Takeoff

Flex Temperature Calculation

Reduced Thrust Takeoff

Derated TakeoffEach derate level is certified and is associated to a new set of performance dataCertified Certified Certified Certified Certified

engine engineengine engineengine

Reduced Thrust Takeoff

Derated Takeoff Weight ThrustIt consists in decreasing the TOGA thrust by steps of 4%

!Max. thrust available

The TOGA thrust can not be selected any more during T/O.

OAT

Reduced Thrust Takeoff

Derated TakeoffDerated Takeoff benefits :

Weight

Thrust

Reduction of engine stress Reduction of minimum control speeds (VMCG/VMCA)

Max. thrust available

Derated Takeoff benefits :

Performance improvement on short runways Allowed on contaminated Runways OAT

Reduced Thrust Takeoff

Derated Takeoff

ThrustTOGA RatingDerated Rating

6 amounts of derate are certified : 4%, 8%, 12%, 16%, 20%, 24%.

Derated Takeoff procedure : pilot cannot recover TOGA.

Derated Thrust

!OAT

OAT

Reduced Thrust Takeoff

Derated Takeoff On a short or a contaminated runway, the main limitation is most of the time the accelerate-stop distance. In order to reduce the ASD, V1 is reduced, till reaching VMCG Min V1 limited by VMCG V1V1V1V1 V1V1V1

Reduced Thrust Takeoff

Derated TakeoffTOGA : VMCG = 111 kts

Reduced Thrust Takeoff

Derated TakeoffTOGA : VMCG = 111 kts DERATE (4%) : VMCG = 109 kts DERATE (8%) : VMCG = 107 kts

Reduced Thrust Takeoff

A319 aircraft // YBHM ATIS : - Takeoff runway 14 - Runway condition Water - CONF 2 - Wind 0 kt - Temperature 20C - QNH 1,013 hPa - Air conditioning OFF - Total Anti-ice OFF

Which of derate levels gives the best TOW ?

Reduced Thrust Takeoff

Derated Takeoff

ThrustTOGA Rating Derated Rating

VMCG/VMCA based on derated thrust

Tref

OAT

Reduced Thrust Takeoff

Conclusion : Which one shall be favored ?

Flexible Takeoff Thrust level is less than TOGA.

Derated Takeoff Thrust level is less than TOGA.

A new set of performance data is Performance for a flex T/O is provided in the Flight Manual for computed by adjusting the max T/O each derate level (use of a specific thrust performance (use of a single T/O chart for each derate level). T/O chart calculated for TOGA). At any moment it is possible to TOGA selection is forbidden. recover TOGA (same minimum control speeds as TOGA). Thrust setting parameters for flex T/O are not considered as T/O operating limits. Flex T/O is forbidden on contaminated runways. No performance improvement. Thrust setting parameters are considered as operating limits for T/O. Derated T/O is allowed on contaminated runways. Increase of T/O weight on short and VMCG limited runways.

Reduced Thrust Takeoff

Reduced Thrust Take OffObjective

Principle

Flexible Takeoff

Derated Takeoff

Flex Temperature Calculation

Reduced Thrust Takeoff

Flex Temperature calculation EXAMPLE

YMML ATIS provides the following data : Takeoff runway 09 Takeoff configuration : CONF 2 Runway condition WET Wind 0 kt Temperature 25C QNH 1010 hPa

BLEEDS STATUS : Air conditioning ON Total Anti-ice OFF Actual Takeoff Weight : ATOW = 67 000 Kg

Determine whether ATOW is lower than MTOW or not (calculate the MTOW with optimized corrections) If ATOW is lower than MTOW, calculate the flexible temperature (with interpolation) and the take-off speeds

Reduced Thrust Takeoff

Flex Temperature calculationYMML ATIS : - Takeoff runway 09 - CONF 2 - Runway condition WET - Wind 0 kt - Temperature 25C

- QNH 1010 hPa - Air Conditioning ON - Total Anti-Ice OFF

MTOW = 75600 Kg

Reduced Thrust Takeoff

Flex Temperature calculationYMML ATIS : - Takeoff runway 09 - Runway condition WET - CONF 2 - Wind 0 kt - Temperature 25C - QNH 1010 hPa - Air conditioning ON - Total Anti-ice OFF Now, lets consider optimized corrections !

Reduced Thrust Takeoff

Flex Temperature calculation- RWY WET - QNH 1010 hPa - Air conditioning ON

Wind = 0 kt

Reduced Thrust Takeoff

Flex Temperature calculation- RWY WET - QNH 1010 hPa - Air conditioning ON

68C = Tvmc : OAT above which takeoff is limited by minimum control speeds Vmcg and Vmca If OAT Tvmc, apply correction of the 2 top lines If OAT > Tvmc, apply correction of the 2 bottom lines

Reduced Thrust Takeoff

Flex Temperature calculation- RWY WET - QNH 1010 hPa - Air co