Originally Posted by
Mechta
take appropriate actions and enter autorotation, he had dislodged the NVGs or otherwise caused them to stop working. Could this have caused him to midjudge the height to flare, or realise much too late that his first choice of landing area was unsuitable?
While the NVG playing some role in what happened, it is rather unlikely that a successfull autorotation was initially entered.
By just screwing up the flare you would probably not be able to effectively stop the rotor prior to impact.
even with a stalled rotor that would take a couple of seconds (somewhere >5s, up to 10s).
Unfortunately it appears something went wrong during entry into AR (delayed for whatever reason to a point where RRPM was so low that recovery was too slow/impossible).
Hence my initial question regarding the error message of the A/P.
Deep, deep back in my mind I had a scenario where the pilot had engaged A/P to allow himself to troubleshoot/anaylse the problem (e.g. the fuel situation) when suddenly the second engine quit. Him having flown that type for quite some time in similar missions would have him not expecting to completely run out of fuel at that flight time. This might have led him to assume some sort of technical problem rather than a straight forward fuel problem.
Regaining situational awareness while under NVG, checking switches on the overhead panel or other things when suddenly it becomes quiet I could imagine would be quite disorienting. I could imagine something like this could slightly delay an entry into AR.
The EC135 has a rather low inertia rotor, so I ssume delaying of entry into AR of much more than 1 or 2s would probably lead to an RRPM in the critical range.