Originally Posted by
megan
rolling, could you elaborate please, first I've heard of it.
Certainly. It is mentioned in 'Before the Storm' by Robert Jackson. 90 Squadron lost 2 Fortress Is 'through structural failure following loss of control during high altitude training flights. Both these accidents were caused by turbulence, the extent and violence of which at altitudes of over 30,000 feet was still an unknown quantity'.
One would assume that if 2 were lost in training this way, then potentially others went the same way on ops.
Some info here:
https://aviation-safety.net/wikibase/74496
I believe there was at least 1 B17C ( which is the model the RAF named Fortress Is) which broke up in flight with the USAAF, so again one assumes more were lost in this way.