FCOM information at time of accident
Quotes
From rudderrudderrat:
"It appears to me that the aircraft was deliberately flown below 50 RA with the speed allowed to wash off, apparently waiting for Alpha Floor to 'save the day'."
From vilas:
"If the speed went below alpha prot only when they went below 100ft then of course alpha floor was disabled. Did the pilot know that?"
Response from rudderrudderrat (my emphasis):
"Probably he did not know that, as the FCTM was published later, and I still can't find a reference in FCOM."
Firstly, the evidence strongly suggests that he was not relying on Alpha-Floor; contrary to what I originally thought.
Secondly, I think he should and would have known of its inhibition below 100R.
Regrettably, I have mislaid the Airbus FCOM volumes dished out to us BCAL (British Caledonian) pilots on arrival at Blagnac for our conversion course on 1/1/1988. Prior to that, we had perused the BCAL Ops Manuals (our own FCOM) dated August 1987. After finishing our ground course and simulator (we were just a week behind the first Air France course), BCAL issued a wide-ranging amendment, dated 17FEB1988, which included considerable changes to the Flight Controls chapter in the Technical Manual. The changes were partly necessitated by changes in FBW logic (Dozy please note), and partly an improvement in the explanations and diagrams.
At both 25AUG1987 and 17FEB1988, the BCAL chapter on Flying Controls describing the Alpha protections aparently fails to mention that Alpha Floor is inhibited below 100R.
However, the BCAL chapter on Power Plant - which includes a description of A/THR, and which remained unchanged from 25AUG1987 in the 17FEB1988 amendments - includes the following:
A/THR can be engaged:
- Manually, by.....
- Automatically, when the pilot initiates a T/O or G/A....
or - if there is an alpha-floor detection after lift-off and down to 100 ft (R.A.) on landing.
In the particular case of alpha-floor detection, the MAX T.O. thrust is automatically selected whatever the position of the thrust lever.
Last edited by Chris Scott; 16th Dec 2013 at 12:32.
Reason: Title added.