Tilt Duct

 

Putting a propeller inside a duct can produce as great as a 50% thrust increase due to the Bernoulli Effect, and also provide additional lift in forward flight. Propeller pitch as well as deflector vanes in the downwash can control the aircraft in hover and transition.

Aircraft in this sub-category include:

Doak 16 VZ-4

Bell X-22A

Nord 500 Cadet