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Guest Stefan Bergert

Airbus A/THR

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Hi all,Could someone take the time please to explain the A/THR on the Airbus? I have a complete A340 FCOM from Airbus and I still can't understand one point, it's doing my head in!I understand most of it, I will explain some of it and then ask some questions.So: The A/THR can be ARMED by: On the ground: pushing the A/THR button when the engines are powered down or by moving the TL to the FLX/MCT or TOGA detents OR: In Flight: By pushing the A/THR button when the TL are OUT of the ACTIVE range or by moving the TL past the CLB detent. The A/THR can be ACTIVE by: pushing the A/THR button whilst the TL are INSIDE the ACTIVE range or by moving the TL between IDLE and the CLB detents but only if the A/THR is ARMED first. When the A/THR is active the thrust or speed is controlled by the various computers (lets not go into this one yet!) upto either: a)the max TLA or :( the detent.Of course the thrust may be controlled manually were the thrust is proportional to the TLA provided the A/THR is not active or armed, and if the levers are moved into a detent then the thrust is set to the detent value set in the FMGC. SO: my question is this: I want to control the thrust manualy, I command 50% power so I move the TL half way up the quadrent. Fine so far, but then I want maximum power so I move the TL to the TOGA detent, the power goes to max and the A/THR arms itself (as above). Then I want to bring the power back down again and resume manual control but as I bring the TL back down into the active range (beteen CLB and IDLE), because the A/THR is ARMED first it now goes to ACTIVE. So in other words I keep having to push the instinctive disconect buttons when controlling the thrust manually if I go to full power and back.Could someone explain?CheersRic

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Hi Ric!YES *gg*! I think, the situation would be as you've described. But I think, you just have to move thrust levers how you like - if you want full power, move them up, ATHR will go to armed, then move them down and ATHR will be active BUT with maximum thrust only corresponding to the TL, eg TLs set to 50%, max. power will be 50% - that's what you wanted to have. It gets difficult if the ATHR then wants to use less power than 50% ;-) So the only advice I can give is: Press the ATHR disconect-button more than 10 secs and there's no ATHR anymore (maybe it's not that good) or: Let the ATHR control the speed - it's not that bad.BTW: I guess you wouldn't change that often from between IDLE and CLB to FLX/MCT or TOGA during an approach because it just shouldn't be required - the only time you require TOGA-power is at TO, GA or windshear conditions (well, ok, stall-recover, but then it's all automatic).Maybe there's still some other way...I just have checked parts of my A320 FCOM (don't have a complete one :-( so no warranty on what's said above ;)Regards,Stefan

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