Hughes XV-9 research helicopter - photo

The Hughes XV-9 was research helicopter designed and built to prove the viability of hot-cycle propulsion, a type of propulsion where the jet efflux was ducted to nozzles at the blade tips.

Fullsize image: https://s3-us-west-1.amazonaws.com/h...r_fullsize.jpg
https://s3-us-west-1.amazonaws.com/h...helicopter.jpg


Previously:

https://www.homemadetools.net/forum/...444#post166276
https://www.homemadetools.net/forum/...207#post161279
https://www.homemadetools.net/forum/...901#post160165
https://www.homemadetools.net/forum/...176#post138386
https://www.homemadetools.net/forum/...690#post159457
https://www.homemadetools.net/forum/...617#post159170

Check out the Hiller Hornet. It also did not require a tail rotor, as it used tiny jet engines on the blade tips. No counter rotation problem, just a rudder. I'll bet it was a scary little devil for the first test pilot.