De Havilland
Maybe this is worth a mention.
My father is a life-long engineer, mostly on aircraft, starting with Seafires ( not great idea, especially at Salerno ) and Hellcats ( great idea ) on Escort carriers, WW2.
He then had a very long hands-on career with Hawkers, ending as main criew chief on development Harrier 2.
I was also on that development team, having first trained in engineering & aeronautics, to join the technical photographic instrumentation side.
Dad & I both agree, after a great deal of study & some direct experience, that DeHavilland were responsible much more than any others for flimsy aircraft.
The Mosquito is remembered in a cosy glow, but how about all the people killed when it was falling apart, let alone being almost unsurvivable in event of an engine out on take-off.
I once photographed a colleague's retirement, upon which John Farley stated " he is the only man I know who's survived a Mosquito engine failure on T.O. "
Even when they built heavy great tanks like the Sea Vixen, they still had flaws enough to overstress & break airframes quite easily ( see the 'widowmakers thread on Pprune ) - and things like the DH 108 were unforgivable - though I admit a lot of the blame there lies in people deciding to continue flying the thing.
It's a sad fact, D.H. have always been fragile designs sticking their necks out - or rather the occupant's necks.
My very best wishes, and condolences, about your son, Tapper's Dad.