First Flight: November 20, 1959 (Very
brief jump)
First Extended Flight: November 24, 1959
Mission: Test bed for large tilt-wing S/VTOL aircraft Designs
Major Accomplishments: First large scale VTOL aircraft produced in
USA and first to test tilt-wing concept.
Power Source: 2 Allison YT40-A-14 turboprop engines
Power Source (NASA, 1959):
Wing Span: 48'
Length: 63'
Weight (Loaded): 33,000 lbs
Maximum Achieved Speed: 253 mph
Additional Information: The X-18 program was the first major
project to investigate the use of tilt-wing short/vertical takeoff or landing
(S/VTOL) aircraft. The Vought XC-142 and the controversial V-22 Osprey are
direct descendents of the X-18.
The X-18 was based on the Chase YC-122 airframe, and was envisioned as a
short-duration, proof-of-concept project. Only 1 X-18 was built.
On the 20th test flight (July, 1961) the tilt control system of one of the engines failed. The X-18 went inverted then into a violent spin. The crew managed to regain control of the X-18 and landed without further problems. After this flight, the X-18 test program was cancelled.
The X-18 apparently does not survive and is believed to have been scrapped.
