Northrop MX-324 / MX-334
Northrop's next flying-wing project was the MX-324, planned as a research aircraft to pave the way for future flying-wing fighters having jet propulsion. It was virtually a low-speed glider at first, because no suitable jet power plant existed. It was also remarkably conventional, having ailerons, flaps /elevators, a minimal body and, later, a large wire-braced fin. The first example had skids, and the tow-car could not pull it off the ground. The second had a jettisonable trolley, which "was not a success." The third had its own fixed tricycle landing gear, the main wheels having trousers and the nosewheel a spat. The nose leg was offset far to the left. This was because the centreline was occupied by the prone pilot, who had an in-teresting panel and control arrangement and rested his head in a cushioned sling inside the glass "bubble" nose. The span was about 28 feet.
Northrop went ahead with the project, under Don B Smith, in September 1942. An Army Air Force contract was awarded in January 1943 and John Myers flew the MX-324 as a glider on October 2, 1943.
By this time Northrop was talking with the infant Aerojet Engineering Corporation of Azusa, which had been formed to advance American rocketry. Their first engine planned for a manned aircraft was the XCAL-200. Though the single thrust chamber had but one thrust level, a mere 200 lb, the whole installation weighed 427 lb. This included a tank of monoethylaniline fuel, a tank of red fuming nitric acid oxidant, four gas bottles to feed the propellants, the thrust chamber and a lot of hydraulic and electric control systems. Most of it was still in bits during the first half of 1944. Early in June, the aircraft was trucked to Harper Dry Lake and static-fired on June 20. On June 22 the staked-down machine was fired for the full burn-time of five minutes. The next day company pilot Harry Crosby taxied under the thrust of the rocket, bringing out the need for "mods". Finally, at dawn on July 5 Crosby smoothly rose into the cool sky on tow behind a P-38 Lightning. He cast off at 8,000 feet, paused for the tug to clear and then pressed the fire trigger on his miniature control column. It went perfectly.
The MX-334 flew under power for 3 minutes 30 seconds on 22 June 1944. On July 11 Crosby dived under power at about 350 mph to very low level before zooming up almost vertically to 6,000 feet. But the MX-324 was a bit of a dead end until new propulsion systems emerged.