May 262012
NACA and the Convertible Aircraft, 1945-9

The convertible aircraft, a vehicle which can function either as a direct lift, rotary aircraft or as fixed wing airplane, with conversion from one to the other type as required, has long been a dream of aeronautical inventors. Combining the vertical flight capacity of the helicopter with the greater efficiency in forward flight of the […]

May 182011
L.H. Leonard "Helicopter-Type Aircraft" VTOL Tailsitters (1939)

Aeronautical history is littered with many unsuccessful VTOL aircraft proposals and prototypes.  Developing a practical military aircraft that takes off and lands vertically while remaining competitive with conventional types in terms of armament, handling, speed, range, payload, etc. has proven to be an enormous challenge, with only a handful of designs achieving production status.  In […]