Please forgive an ignorant question – I know very little of the subtleties of rotary flying – but if it's possible to do a 1g barrel roll in a fixed-wing, isn't it possible to do a 1G barrel roll in a helicopter without stressing either the airframe or the moving parts?
You keep positive g throughout the manoeuvre and acceleration towards the centre of the manoeuvre but it goes more and less than 1g but not into negative figures (unless you cock it up)
