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factsonly
26th Jan 2010, 07:55
I've noticed in the A320 that in the emergency electrical configuration, engine 2 goes to approach idle inflight even when clean and engine remains at flight idle when idle thrust is selected. Can anyone provide an explanation?

TyroPicard
26th Jan 2010, 10:05
I can't think of any reason why the two engines should behave differently.. how big is the difference?
Incidentally "flight idle" does not exist on A320, it is modulated idle with Flap lever at Zero, idle varies with bleed setting.
Approach Idle uses a/c altitude and Flap lever position - so on a clean a/c how do you know which applies? Answer - I certainly don't!
Perhaps the FADEC's disagree slightly..
Edit: I assume you are talking Simulator - have you told the engineers?

catiamonkey
28th Jan 2010, 03:03
Only SFCC 1 is supplied in EEC. FADEC 2 doesn't get any information on flap position, so it defaults to approach idle and cont ign (depending on engine). Same thing happens to eng 1 if SFCC 1 fails with a FLAP SYS 1 FAULT.

factsonly
30th Jan 2010, 01:34
catiamonkey thankyou very much for that. I had observed the same thing in a simulator in hong kong years ago. The airline I am working for now is running a cyclic which ends up in the EEC and whilst I was able to point out the differing idle, I was scratching my head as to why it happens. Thanks again