I agree that they haven't "taken off," but we do still have them: https://en.wikipedia.org/wiki/Bell_Boeing_V-22_Osprey https://en.wikipedia.org/wiki/Bell_Boein

I agree that they haven't "taken off," but we do still have them: https://en.wikipedia.org/wiki/Bell_Boeing_V-22_Osprey https://en.wikipedia.org/wiki/Bell_Boeing_V-22_Osprey Helicopters are expensive to operate and maintain. It's hard to keep something hovering.