I was looking whether this is an established fact or just media derivative of whad had actually been released. No luck so far, can anyone help?
I believe this was a conclusion arrived at as the 'only plausible' explanation. The authorities mentioned it, but I'm not sure if they confirmed having heard the switch selection on the CVR.
To explain it any other way would require a series of largely implausible scenarios, ie:
1. Neither the captain, nor anybody else, tries to enter the code (implausible)
2.
Everybody on that aircraft who is supposed to know the code has forgotten it (implausible)
3. Given 1 and 2 above, the keypad must have been overridden from inside the flight deck, using a guarded switch in a position unlikely to have been activated accidentally (only plausible explanation)
4. Override functions for 5 mins (with LH, confimed by LH CEO), then entry can be attempted again. Continued denial requires further deliberate action from the FD (not possible if incapacitated).
5. Door failure - certainly possible, but doesn't address at all the primary issue of the aircraft being commanded into a descent. Or why the FO didn't respond to multiple attempts to get his attention, from both inside & outside the ac.
The only plausible explanation for what transpired is the deliberate action of the FO - when viewed in the context of the other deliberate action taken (commanding descent).
Personally, I don't believe
any rash or premature conclusions have been reached - no matter how much we would naturally wish to defend 'one of our own'.