Pilotmike ... Sorry you pehaps missundertood me, I meant jumping off the high board, which in kit which is what we did at Cranditz.
Crab.... It was diificult to work out the drop height, I think it was more probably 20ft, but at a hover height of 50 ft, how much forward coluld you travel in the event of an engine failure before impacting.
I'm not sure if the Lyme Regis accident was a Wessex 3 or 5, but either way assuming an sile engine failure with one or two engines at say 50ft, spool up time, I guess you going down.
It would be interesting if anyone remembers the Lyme Regis accident, it was RN out of Portland, I have photos somewhere.