Lockheed YP-24

Last revised June 10, 1999

The Lockheed-Detroit YP-24 of 1931 was a design ahead of its time. It was the first USAAC low-wing monoplane fighter with retractable undercarriage and was the first USAAC fighter with enclosed cockpits. Perhaps more significantly for later developments, it was the first military pursuit design to carry the Lockheed name, although at that time Lockheed was owned by the Detroit Aircraft Corporation of Michigan.

The Lockheed Aircraft Company of Santa Barbara, California had been a going concern all throughout the 1920s, its best-known product being the famous Vega high-wing monoplane which had set so many records. However, in 1929, the management of Lockheed voted to sell majority share ownership to the Detroit Aircraft Corporation, a Michigan-based holding company which already owned the Ryan and Eastman aircraft companies and which also had a substantial manufacturing capacity in Detroit. In July 1929, the Detroit Aircraft Corporation acquired 87 percent of the assets of Lockheed. On the surface, it appeared that the change of owners was not going to affect the day-to-day business of Lockheed, and the operationally-independent California team went right on producing Vegas, Air Expresses, and Explorers. New designs were also forthcoming: In 1929 Lockheed produced the Sirius, in 1930 they produced the Altair, and in 1931 the Orion appeared.

However, the Detroit holding company had some ideas of its own, and these resulted in Lockheed's first entry into the pursuit field. The Detroit company undertook the private development of a prototype of a two-seat fighter based on the design of the Lockheed Altair low-wing cantilever monoplane of 1930. The Altair was unique for its time in that it possessed a cantilever monoplane wing with a fully-retractable main undercarriage. The chief engineer responsible for the project was Robert J. Woods, who was based in Detroit.

A mockup of the fighter was completed in March of 1931. It bore the Wright Field project number of XP-900. The slim metal fuselage and the metal tail surfaces were built by Detroit Aircraft, but the wood-framed, plywood-covered wings as well as the undercarriage were essentially those of the Altair and were built by Lockheed in California. The final assembly and the initial testing of the aircraft were done in Detroit by the parent company.

The XP-900 was powered by a 600 hp Curtiss Conqueror V-1570C (the military designation was V-1570-23) liquid-cooled 12-cylinder vee engine driving a three-bladed propeller. The tunnel radiator and the oil cooler were housed beneath the engine just ahead of the wing. The crew of two (pilot and gunner) was housed back to back in enclosed cockpits. The aircraft was armed with two synchronized machine guns (one 0.30-in and one 0.50-in) mounted in the upper fuselage nose, plus one flexible 0.30-cal gun operated by the gunner firing upward and to the rear.

Brief manufacturer's trials were conducted in Detroit during the summer of 1931. The XP-900 was delivered to Wright Field on Sept 29, 1931. At that time, the plane was purchased by the USAAC and given the designation YP-24. It was assigned the USAAC serial number of 32-320. The YP-24 underwent testing as a potential replacement for the Berliner-Joyce P-16 two-seat pursuit. The speed of the YP-24 was impressive for its time--it was 40 mph faster than the P-16, but it was also 20 mph faster than the P-6E, at that time the fastest fighter in the USAAC inventory. Maximum speed was 235 mph. Initial climb was 1820 feet/minute. Service ceiling was 25,000 feet and range was 556 miles. Weights were 3010 lbs. empty, 4360 lbs. loaded.

As a result of the tests, the War Department ordered five Y1P-24 two-seat fighters and four Y1A-9 attack planes. The Y1A-9 attack version differed from the pursuit version in being powered by a V-1570-27 rated at a lower altitude and carried a heavier forward-firing armament plus bombs.

The YP-24 seemed to have a promising future ahead of it. However, on October 19, 1931 the YP-24 prototype was lost when its pilot was ordered to bale out rather than attempt a wheels-up landing after the undercarriage lever had broken off. This problem was, of course, easily correctable, but for reasons unrelated to the YP-24 accident, some rather harsh economic realities were about to overtake the Detroit Aircraft Corporation.

The timing of Detroit's acquisition of Lockheed had been particularly unfortunate, since it took place only three months before the stock market crash which was to plunge the USA into the Great Depression. As the Depression deepened, the Detroit Aircraft holding company found that it was in over its head. Rising losses from other operations drained it of any profit. On October 27, 1931, the Detroit Airctraft Corporation went into receivership.

The bankruptcy of the Detroit holding company meant that it could not undertake the manufacture of the Y1P-24s and Y1A-9s. The project was tentatively shelved. It did not revive until after Robert Woods had joined the Consolidated Aircraft Corporation, but that is another story!

It looked like the Depression had Lockheed on the ropes. The bankruptcy of its holding company caused the Lockheed Aircraft Corporation subsidiary to be placed under the aegis of the Title Insurance and Trust Company of Los Angeles. Staff was cut to the bone, but operations were able to continue on a shoestring basis. However, on June 16, 1932 the end of the line finally came and the doors of the Lockheed Aircraft Corporation were shut.

It would seem that Lockheed would be just one out of many casualties of the Depression, going down the tubes in much the same manner as did Thomas-Morse and Berliner-Joyce, its name never to be heard again. However, only five days after the doors of the corporation had been locked, a miracle took place. A new group of investors bought the assets of the now-defunct Lockheed Aircraft Corporation for only $40,000, and the company was brought back from the dead. And the rest, as they say, is history!


  1. The American Fighter, Enzo Angellucci and Peter Bowers, Orion Books, 1987.

  2. Lockheed Aircraft Since 1913, Rene J. Francillon, Naval Institute Press, 1987.