page_title: Lockheed P-38 Lightning
section_title: XP-38 and YP-38 prototypes
hierarchical_section_title: Lockheed P-38 Lightning / Design and development / XP-38 and YP-38 prototypes
caption_attribution_description: YP-38
context_page_description: The Lockheed P-38 Lightning is a World War II–era American piston-engined fighter aircraft. Developed for the United States Army Air Corps, the P-38 had distinctive twin booms and a central nacelle containing the cockpit and armament. Allied propaganda claimed it had been nicknamed the fork-tailed devil by the Luftwaffe and "two planes, one pilot" by the Japanese. Along with its use as a general fighter, the P-38 was utilized in various aerial combat roles including as a highly effective fighter-bomber, a night fighter, and as a long-range escort fighter when equipped with drop tanks. The P-38 was also used as a bomber-pathfinder, guiding streams of medium and heavy bombers; or even other P-38s, equipped with bombs, to their targets. Used in the aerial reconnaissance role, the P-38 accounted for 90 percent of the aerial film captured over Europe.
  The P-38 was used most successfully in the Pacific Theater of Operations and the China-Burma-India Theater of Operations as the aircraft of America's top aces, Richard Bong, Thomas McGuire and Charles H. MacDonald.
context_section_description: Lockheed won the competition on 23 June 1937 with its  Model 22 and was contracted to build a prototype XP-38 for US$163,000, though Lockheed's own costs on the prototype would add up to US$761,000. Construction began in July 1938, and the XP-38 first flew on 27 January 1939 at the hands of Ben Kelsey.
  Kelsey then proposed a speed dash to Wright Field on 11 February 1939 to relocate the aircraft for further testing. General Henry "Hap" Arnold, commander of the USAAC, approved of the record attempt and recommended a cross-country flight to New York. The flight set a speed record by flying from California to New York in seven hours and two minutes, not counting two refueling stops, but the aircraft was downed by carburetor icing short of the Mitchel Field runway in Hempstead, New York, and was wrecked. However, on the basis of the record flight, the Air Corps ordered 13 YP-38s on 27 April 1939 for US$134,284 each. (The "Y" in "YP" was the USAAC's designation for a prototype, while the "X" in "XP" was for experimental.) Lockheed's Chief test pilot Tony LeVier angrily characterized the accident as an unnecessary publicity stunt, but according to Kelsey, the loss of the prototype, rather than hampering the program, sped the process by cutting short the initial test series. The success of the aircraft design contributed to Kelsey's promotion to captain in May 1939.
  Manufacture of YP-38s fell behind schedule, at least partly because of the need for mass-production suitability making them substantially different in construction from the prototype. Another factor was the sudden required expansion of Lockheed's facility in Burbank, taking it from a specialized civilian firm dealing with small orders to a large government defense contractor making Venturas, Harpoons, Lodestars, Hudsons, and designing the Constellation for TWA. The first YP-38 was not completed until September 1940, with its maiden flight on 17 September. The 13th and final YP-38 was delivered to the Air Corps in June 1941; 12 aircraft were retained for flight testing and one for destructive stress testing. The YPs were substantially redesigned and differed greatly in detail from the hand-built XP-38. They were lighter and included changes in engine fit. The propeller rotation was reversed, with the blades spinning outward (away from the cockpit) at the top of their arc, rather than inward as before. This improved the aircraft's stability as a gunnery platform.
caption: One of 13 YP-38s constructed
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