To try and answer all questions
FOR AIRBUS PILOTS.
WHEN BEFORE FLIGHT DO YOU ENGAGE A/TH ?
WHEN DOES IT BECOME ACTIVE ?
HOW IS IT MANAGED BEFORE LANDING?
WHEN AFTER FLIGHT DO YOU DISCONNECT IT ?
Autothrust is armed on the ground when flex or toga is selected for take off ( as three twenty stated) We know this by Autothrust BLUE in the right hand corner of the FMA.
As previously stated it becomes active at thrust reduction altitude, we again see a change on the FMA as it has changed to white (active). The active range on two engs is from idle to clmb, in single eng op's, it is active between idle and MCT. If at any stage you advance the TL out of the detent for the twin or single eng range athr will go BLUE again as it is again armed.
As for disconnection, there are two types... 231-232cpip. The standard procedure (airbus) is to retard the TL to the actual power setting and then disconnect the Athr. Previously if in clmb you disconnect the AThr you would get Thrust locked until you moved the TL and then the thrust would go to the actual position of the TL. The newer type (232cpip) is such that as soon as you disconnect ATHR it will go to the actual position of the TL rather than waiting for you to remove it from the clmb gate.
Athr is disconnected in 3 ways, selection of idle, the instinctive disconnect buttons on the TL and the Athr button on the FCU. On landing IDLE is selected for touch down therefore Athr is disconnected. Hope this helps
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Gravity always wins....
[This message has been edited by Silky (edited 17 October 2000).]