The Northrop M2-F3 was a heavyweight lifting body rebuilt from the Northrop M2-F2 after it crashed at the Dryden Flight Research Center in 1967. It was modified with an additional third vertical fin - centered between the tip fins - to improve control characteristics. The "M" refers to "manned" and "F" refers to "flight" version.
Northrop M2-F3
The M2-F3 at the National Air and Space Museum
Image: M2F3museum
Image: M2F3museum 1
A lifting body is a fixed-wing aircraft or spacecraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage with little or no conventional wing. Whereas a flying wing seeks to maximize cruise efficiency at subsonic speeds by eliminating non-lifting surfaces, lifting bodies generally minimize the drag and structure of a wing for subsonic, supersonic and hypersonic flight, or spacecraft re-entry. All of these flight regimes pose challenges for proper flight safety.
US X-24A, M2-F3 and HL-10 lifting bodies
The Martin Aircraft Company X-24 built as part of a 1963 to 1975 experimental US military program
Burnelli General Airborne Transport XCG-16, a lifting body aircraft (1944)