jcjeant wrote
Two questions I could not find the answer to in this thread (bear with me if I overlooked them):
1. auto-trim moved the THS to up 13° while the PF was pulling up -- was the auto-trim movement a consequence of the PF's pulling up?
2. would a full down sidestick have had the authority to overcome the full up THS later on?
Those questions were already answered
It's YES for the 2 questions if the airplane was acting like it must be in alternate law
Pull up and the THS will go up
Pull down and the THS will go down
The BEA report tell us that the THS remained at 13% nose up including during the nose down stick input that occured during the descent, before 10000 ft. Therefore
one (at least) of the following must hold true:
- THS movement under alternate law is more complex than suggested above; e.g. delayed, and the nose down command was shorter;
- the THS moved slightly but the BEA report does not mention it;
- flight law was not alternate law; direct? abnormal? sub-variant of alternate?
- there was a trim malfunction (but it seems unlikely that the BEA report does not mention it at this stage, so I rule this one out)
Any authoritative source on exactly how the autotrim works in the various flight laws?