well as a demo to students in an old heli ( S 300C ) fly downwind at 17"map trying to hold height She looses translational lift at around 20 kts, ROD now about 500 ft plus.Now in IVRS, Pull power up to 24 inches and guess what aircraft climbs back up again. I have to have more than about 800 ft a min for the aircraft not to be able to pull herself out of the situation