Came late to this. Nice one Mark12. Just to add, in any normal flight condition the force on the props will be in a forwards direction, as an equal and opposite reaction to thrust. It’s only if the prop is already acting as a brake – a negative angle of attack (not pitch) – that they would be pushed backwards. A stopped/windmilling prop, or one that can’t attain sufficient pitch to match forward speed. Much more likely the former!