Bell D-188A

The Bell D-188A was a proposed eight-engine, Mach 2 capable vertical take-off and landing tiltjet fighter that never proceeded past the mock-up stage. In 1955 the USAF and the US Navy both asked Bell Aircraft to develop a supersonic all-weather fighter-bomber and interceptor, designated the Model 2000 and offered as the D-188 for the Navy and the D-188A for the Air Force. Four General Electric J85 engines sat in wing pods that rotated to direct thrust downward for takeoff, and four more engines were in the fuselage, two of them vertical liftjets. Bell showed the design publicly on 5 December 1960 as the XF-109, although that designation was never officially assigned, and in spring 1961 the Air Force cancelled the program with no aircraft built.