The 10 prototype G-ARTA had an eventful early life doing stalling tests for the type. It was on one of these that as BT put it 'All h... broke loose' and he thought they would loose the machine.
Not sure of the sequence but two engines 'rotated' in their mountings causing associated loss of hydraulics and instumentation, one elevator went unstable and all in all it was obviously a very alarming situation. This is the flight where they tried to operate the escape hatch.but when fired the trunking inside collapsed. After slowing down to near the stall speed the elevator calmed down and they were able to 'drop the gear' and return to Wisley. The poor old girl had done hundreds of stalls and was probably lucky to survive.
Survive she did and went into service with BCAL but was severly damaged in a landing accident at Gatwick 28 01 72 never to fly again, no doubt having spent many years in the Aviation eqiv of PTS. I would highly recommend this book to anyone wishing to revisted the time when flight testing had to be done before simulator experience available.