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 […]

Mar 302012
 
Scherrer Jet Propulsion Airplane Proposal (1943)

Avid students of the history of jet propulsion may be aware of “Jake’s Jeep,” a ducted-fan engine similar to the Campini design that was developed at NACA Langley by Eastman Jacobs and Albert E. Sherman from 1941 to 1943 before being abandoned in favor of superior turbojet technology imported from England. Even a dedicated research […]

Nov 032011
 
Ljungstrom Internal Propulsion Aircraft Projects (1928)

In 1928, Olof Ljungstrom of Detroit, Michigan submitted a pair of unusual aircraft proposals to NACA which featured boundary layer removal via a primitive form of jet engine, in which a piston engine drove an axial flow turbine blower inside the aircraft. The power plant is reminiscent of that used by the Caproni Campini N.1, […]

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 […]