41G: TECH UPDATE Flashcards
SOP Parking Parking Brake Release
The Nov 2022 FCOM revision, advises flight crew to not press the brake pedals before releasing the parking brake after engine shutdown. This is to avoid activation of the
Zero Torque Pressure (ZTP) function.
The Zero Torque Pressure (ZTP) function puts the alternate pistons of the brakes in close proximity with the brake carbon discs. It prevents the loss of hydraulic fluid from the accumulator, due to repeated brake applications. The function activates when the flight crew presses the brake pedals and only the yellow accumulator supplies the brakes (i.e. engines not running).
In case the system is activated during normal operations, as the pistons are kept near the carbon brake discs, even when the parking brake is not engaged, the high temperature of the brake is transferred to the pistons. This may cause an early degradation of the brake pistons, due to the heat transferred from the carbon brake discs.
AUTO FLT YAW DAMPER 1(2) System Reset “IF AP is inoperative” condition
If at least two IR sources are rejected by FAC monitoring, the AUTO FLT YAW DAMPER1(2) alert message is triggered. This will also lead to disengagement of the AP and preventing any AP engagement. In some cases, during take-off, the FAC is sensitive to vibration and may reject the IRS, as a consequence, the failure “AUTO FLT YAW DAMPER 1(2)” is triggered and AP is lost.
In case AP is inoperative, the failure is latched in the FAC and can be unlatched through the
FAC Pb reset. Unlatching the rejection will recover the AP availability. As per Airbus In service experience, the FAC reset does not rectify the fault in case AP is operative, hence the IF AP is inoperative” condition.
L/G Gravity Extension Procedure
The L/G GEAR NOT DOWNLOCKED alert takes into account different types of failures of the landing gear extension system. The CAM procedure associated with this alert requests the flight crew to recycle the landing gear once.
Regardless of the root cause of the failure, additional recycling attempts may significantly enhance effectivity of the procedure. This may enable the pressurized extension of the landing gear before the gravity extension is performed. Up to ___ recycling attempts may be required to ensure a successful landing gear extension in some situations.
Therefore, in addition to the first recycling attempt, included in the L/G GEAR NOT DOWNLOCKED procedure, additional attempts are introduced at the beginning of the [QRH] L/G GRAVITY EXTENSION procedure.
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