Originally Posted by
jonas64
Personally I would consider vasovagal syncope before I'd consider anything more sinister. If someone was predisposed (perhaps unknowingly) to this during stressful or emotional situations, the final stages of your first solo circuit could potentially be a trigger. Granted the student pilot had flown solo in ultralights, but still...
I wouldn't.
A reasonably-trimmed aircraft - or even something that's not that well trimmed, doesn't pitch 30* nose down and accelerate beyond Vne in the absence of an external (pilot/CG shift/structural failure) input. It may change it's flight path slightly to hunt down it's desired 'trimmed-to' airspeed, no argument there, but not
that much.