ORIGINAL: combatpigg
One of the first model aviation guide books I ever cracked open claimed that some C/L speed plane combos acheived 100% prop efficiency, if not better.
I guess you need to define efficiency here. A 0 pitch prop could fly a plane because of the airfoil shape. Is that exceeding 100% efficiency? I think a dive would be cheating. Other then that we would have perpetual motion and I would like a piece of that pie.
Now let me think about HighPlains and terminal velocity.