Loved the G5A and the G3B1 but the word inertia cannot be applied in any way shape or form to the venerable (Franklin engine) H1 that I had the dubious pleasure to fly on an air-test when it came in for maintenance. I think it was a 1956 model. The RFM advises a running take off and even illustrates the technique with the necessary sketches. See
Restoring the Bell 47H-1
Yes the G5A and G3B1 has high inertia blades and such were their engine-off characteristics that my boss used to demo an EOL on to the pill-box on the southern edge of dear old Fairoaks. I was ne'er so brave but I could hit the target square just about every time. Great machine.
Had to do an EoL for real in a G5A with (Sir) Norman Foster when the newly furbished rotor head fooled the balance chappie and it threw off pitch so violently that we both thought the end of the world had come. Turned of the engine on the way down to a nice grass meadow. New underpants all-round.
G.
