Northrop XP-79B Jet Fighter

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Northrop’s flying-wing concept took a dramatic step forward in 1942, when he convinced the U.S. Army Air Forces (USAAF) that he could build a fighter that could reach the speed of sound. Beneath the USAAF-classified wraps, ‘Project 12,’ as the design was designated, was a rocket-powered flying wing with a wingspan of only 32 feet. The pilot was to fly it in a prone position, the rationale being that such a posture would make him less vulnerable to G-forces and raise his ‘blackout threshold’ beyond normal human limits.

The first experimental vehicle under Project 12 was the MX-324, a glider that was to be followed by a powered version called the MX-334. A simple steel tube and wood affair with faired, fixed landing gear, the MX-324 had a wire-braced vertical fin that looked as if it had been added as an afterthought–which, in fact, it had been, since it could be and later was removed. In one of the most undignified methods ever devised for getting into an airplane, the pilot had to clamber up on the trailing edge of the wing and slither on his stomach through a triangular hatch. After some unsuccessful attempts to use an automobile to tow the MX-324 skyward, it was towed into the air behind a Lockheed P-38 Lightning.

During an early flight, the MX-324’s test pilot, prewar racing pilot Harry Crosby, encountered trouble when turbulence behind the P-38 towplane flipped the glider upside down. The MX-324 went into a spin. Even when it suddenly came out of the spin, it was still inverted and descending in ever-tightening circles.

Crosby jettisoned the two-part hatch-canopy, climbed out on the wing and kicked free. After his parachute opened, however, he saw the runaway glider coming right at him. As luck would have it, the wayward wing narrowly missed Crosby and came down in the desert a short distance from where he came to earth. Little could Crosby have suspected that he would find himself in a similar situation in a similar airplane two years later…with a far less happy landing.

The MX-334 took to the air in October 1943 for some unpowered testing while the Aerojet Corporation completed its XCAL-200 rocket engine, which was to be powered by monoethyaniline fuel, oxidized by red fuming nitric acid. The MX-334 made its first flight with the new engine on June 23, 1944, and fulfilled Northrop’s promise to the USAAF. Although capable of only 3.5 minutes of powered flight, it was the first American rocket-powered aircraft to fly.

Despite the effort put into the secret project, the USAAF ultimately concluded that the rocket-powered MX-334 was a dead end. Much research data had been culled from it, however, and Northrop had a spinoff of Project 12 in the offing that the USAAF regarded as being militarily far more feasible–the XP-79.

Essentially, the XP-79 was an interceptor that would bring down its opponents by ramming them in flight. During the early months of the German invasion of Russia in 1941 and 1942, Russian fighter pilots had frequently resorted to various taran, or midair ramming techniques. There was no real need for American fighter pilots to resort to such tactics, however, and the USAAF officer who came up with the idea for the ram fighter may be grateful that his identity is lost to history. In any case, in January 1943, Northrop was awarded a contract to build three XP-79 Flying Ram prototypes, each of which was to be powered by an Aerojet rocket engine with 2,000 pounds of thrust.

A plague of developmental problems with the proposed Aerojet engine, and the unlikelihood of its being able to keep the plane airborne for more than 30 minutes, led the USAAF to cancel its order for the rockets and for two of the XP-79s that were to be powered by them. The Army did, however, consent to completion of the third prototype, which used two Westinghouse 19B axial-flow jet engines with 1,345 pounds of thrust each. The jet-engine revision, designated the XP-79B, weighed 5,840 pounds empty and 8,669 pounds with a full operational load.

Tags: Aircraft, Aviation History, Flight Technology

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