Originally Posted by
CONF iture
- The part after the AP disconnect has some logic :
Whenever FD reengage, they do it basic mode, which is HGD – V/S.
If procedures had been followed, the F/Ds should have been switched off until the problem was solved.
- The part
before the AP disconnect raises questions :
- The V/S trace in red is partially masked by the green line, but seems to indicate an oscillation getting stronger, up to the AP disconnect.
- It could indicate that the AP was trying to follow that cycling SEL V/S ?
Because the red trace is masked it's hard to tell, but it could equally be the lumps and bumps you'd associate with turbulence. Some confirmation that SEL V/S is not used in the mode the aircraft was in would be useful - but there are plenty of explanations, such as the FDR using that channel for something else at that point - I'm almost sure the negative peaks indicate a bad value rather than anything selected though.
Let's reserve judgment until the final report before we get our knickers in a twist though.