Stall Recovery
I know it has been posted several times before......
Stall Recovery FCTM.
ISSUE DATE: 15 JUN 10
STALL RECOGNITION
The flight crew must apply the stall recovery procedure as soon as they
recognize any of the following stall indications:
‐ Aural stall warning
The aural stall warning is designed to sound when AOA exceeds a given
threshold, which depends on the aircraft configuration and Mach number.
This warning provides sufficient margin to alert the flight crew in advance
of the actual stall even with contaminated wings.
‐ Stall buffet
Buffet is recognized by airframe vibrations that are caused by the non-stationary
airflow separation from the wing surface when approaching AOAstall.
When the Mach number increases, both the AOAstall and CL MAX will decrease.
The aural stall warning is set close to AOA at which the buffet starts.
For some Mach numbers the buffet may appear just before the aural stall warning.
STALL RECOVERY
‐ The immediate key action is to reduce AOA:
The reduction of AOA will enable the wing to regain lift.
This must be achieved by applying a nose down pitch order on the sidestick.
This pilot action ensures an immediate aircraft response and reduction of the AOA.
In case of lack of pitch down authority, it may be necessary to reduce thrust.
Simultaneously, the flight crew must ensure that the wings are level in
order to reduce the lift necessary for the flight, and as a consequence, the required AOA.
As a general rule, minimizing the loss of altitude is secondary to the
reduction of the AOA as the first priority is to regain lift.
As AOA reduces below the AOAstall, lift and drag will return to their normal values.
‐ The secondary action is to increase energy:
When stall indications have stopped, the flight crew should increase thrust
smoothly as needed and must ensure that the speed brakes are retracted.
Immediate maximum thrust application upon stall recognition is not appropriate.
Due to the engine spool up time, the aircraft speed increase that results
from thrust increase, is slow and does not enable to reduce the AOA instantaneously.
Furthermore, for under wing mounted engines, the thrust increase
generates a pitch up that may prevent the required reduction of AOA.
When stall indications have stopped, and when the aircraft has recovered sufficient energy,
the flight crew can smoothly recover the initial flight path.
STALL WARNING AT LIFT-OFF
If the aural stall warning sounds at liftoff, the flight crew must fly the
appropriate thrust and pitch for takeoff in order to attempt to stop the
aural stall warning and ensure a safe flight path.
The flight crew applies TOGA thrust in order to get the maximum available thrust.
Simultaneously, the pilot flying must target a pitch angle of 15 ° and keep
the wings level in order to ensure safe climb.
Then, when a safe flight path and speed are achieved, if the aural stall
warning is still activated the flight crew must consider that it is a spurious warning.