The Lockheed P-80 Shooting Star was the first American combat-ready jet fighter, and was the first American production combat aircraft to exceed 500 mph in level flight. It was the first American jet-powered aircraft to score a victory in air-to-air combat, and was the victor in the world's first jet-versus-jet combat. It participated in the world's first operational combat mission that was assisted by mid-air refuelling. For a brief time, it held the world's air speed record. And perhaps most significant, it formed the basis of the T-33 two-seat advanced trainer, one of the most successful trainers of the postwar era.
The USA got off to a late start in the new field of jet propulsion. The Germans had pioneered jet propulsion with the Heinkel He 178 V1, which was flown for the first time on August 27, 1939. The world's first jet-powered fighter, the Heinkel He 280 V1 flew for the first time on April 2, 1941. The Messerschmitt Me 262 V-3 took to the air under jet power for the first time on July 8, 1942. The British were not far behind the Germans, the Gloster E.28/39 experimental testbed having been flown for the first time on May 15, 1941 powered by a Whittle W2B turbojet engine with centrifugal supercharger. The Gloster Meteor flew for the first time on March 5, 1943, powered by a pair of 1500 lb.s.t. Halford H.1 turbojets. The prototype de Havilland DH-100 Vampire flew on September 21, 1943, powered by a single 2700 lb.s.t. Halford H.1 (Goblin) turbojet.
As far back as 1939, Lockheed engineers Clarence R. "Kelly" Johnson and Hall L. Hibbard had been interested in jet propulsion for aircraft, and had actually engaged in various paper projects. In particular, Lockheed had done some preliminary work on a company-financed project designated L-133 which had progressed to several different versions on the drawing board, culminating in the Model L-133-02-01, which was a canard design powered by a pair of Lockheed-designed L-1000 turbojet engines. The USAAF was not particularly interested in any of these projects and declined to finance any of them, so none of them ever progressed past the preliminary concept stage. However, spurred by reports from England on progress there with jet propulsion, and perhaps even more so by intelligence reports of German and Italian advances in the area of jet propulsion, the USAAF suddenly began to show more interest in jet-powered combat aircraft.
In exchange for the generous Lend-Lease aid provided to England by the USA, the British agreed to supply blueprints of their new jet engines to the USA, where they would be built under license by General Electric. Powered by a pair of General Electric I-A turbojets, the Bell XP-59A Airacomet made its maiden flight on October 19, 1942. Although the XP-59A provided valuable experience to the USAAF in the operation of jet-powered aircraft, it was basically a flying testbed and not a combat-capable aircraft. The USAAF had to look elsewhere in its search for an effective jet fighter.
In light of its pioneering work on the XP-59A Airacomet, the Bell Aircraft Corporation might have been a more likely choice than Lockheed for work on a more combat-capable jet fighter. However, the Bell corporation was heavily committed to other projects and could not take on any more work. In view of Lockeed's earlier studies in jet propulsion, in late 1942, the USAAF transferred to Lockheed the preliminary design studies undertaken by Bell for the XP-59B single-engined version of the Airacomet. In March of 1943, the specifications and drawings for the Halford H.1B (Goblin) turbojet were also transferred to Lockheed. This engine was to built under license in the USA by Allis-Chalmers as the J36.
In the spring of 1943, preliminary discussions were carried out between Lockheed representatives and the Air Technical Service Command about the production of a combat-capable jet fighter. On May 17, 1943, a conference chaired by Brig-Gen Franklin O. Carroll, chief of the Army Air Forces Engineering Division formalized these preliminary discussions. Lockheed was invited to submit a fighter proposal built around the de Havilland-built Halford H.1B turbojet. Immediately afterwards, Lockheed undertook a preliminary design investigation for a jet fighter project named L-140 by the company. On June 17, 1943 the USAAF gave its approval to the L-140 project, and on June 24 a formal Letter Contract was issued. The designation XP-80 was chosen for the project. On October 16, a formal contract was issued. One of the key requirements imposed on Lockheed was the need to complete the first aircraft within 180 days of the award of the Letter Contract.
In order to meet this schedule, Clarence L. "Kelly" Johnson, assisted by William P. Ralston and Don Palmer, assembled a small team of engineers and went to a ten-hour day/ 6-day week schedule. They housed themselves in a temporary building near the wind tunnel at Plant B-1 and set out to design the L-140 and to build the prototype XP-80 in record time and in complete secrecy. They operated almost completely outside the normal company bureaucracy, and proceeded with a minimum of paperwork and overhead. This was the origin of the famous Skunk Works.
The Skunk Works team adopted a simplistic approach. The team settled on a clean aircraft with a low aspect ratio, laminar-flow wing. Conventional tail surfaces and a retractable nosewheel undercarriage were adopted. The Halford H.1B engine was to be fed by air intakes positioned in the lower fuselage forward of the wing leading edge and exhausted through a straight tailpipe. The pilot sat in a pressurized cockpit underneath a rearward-sliding bubble canopy. The aft fuselage with engine and tail surfaces was detachable as a single unit for ready access to the powerplant. The armament was to consist of six 0.50-inch machine guns, all mounted in the nose.
The mockup of the XP-80 was ready for inspection on July 20-22, 1943. Only a few minor changes were recommended by the inspectors, and construction of the XP-80 (serial number 44-83020) proceeded rapidly. Since the project had the highest priority, construction went so rapidly that the XP-80 was soon ahead of schedule. The pressurized cockpit was considered unnecessary for the first prototype, so it was decided that an unpressurized cockpit would be fitted in order to save time. However, the jet engine program did not proceed quite so rapidly and the delivery from England of the first non-flyable turbojet was delayed several times, forcing Lockheed to use a wooden engine mockup for the first tests.
The non-flyable engine was finally delivered on November 2, 1943. This engine was installed in the XP-80, and the aircraft was trucked from Burbank to Muroc Dry Lake. On November 16, the XP-80 was formally accepted by the USAAF, beating the schedule by completing the aircraft within 143 days from the date of award of the Letter Contract.
While the XP-80 was still under construction, some consideration had been given to installing a less powerful General Electric I-16 (license-built Whittle W2B) jet engine for initial testing, with production aircraft being powered by the more powerful Halford H.1B built under license by Allis-Chalmers as the J36. However, the XP-80 would be decidedly underpowered with the I-16, and this idea was dropped.
However, the J36 program ran into difficulties and ultimately failed to produce anything useful. In September 1943, Lockheed proposed as an alternative a larger and heavier L-141 version, to be powered by a General Electric I-40 (later produced by both General Electric and Allison as the J33). The USAAF was sufficiently impressed that they issued a contract for two XP-80As. Serials were 44-83021 and 44-83022.
A flyable Halford engine was delivered to Lockheed in mid November of 1943. The de Havilland-built Halford H.1B turbojet had a bench thrust of 3000 pounds at 10,500 rpm and an installed thrust of 2460 pounds at 9500 rpm. On November 17, 1943, while the H.1B engine installation in the XP-80 was undergoing ground testing, both intake ducts collapsed, and the ingestion of debris damaged the engine. While waiting a replacement engine, the ducts were strengthened. The British selflessly rushed over a replacement engine which had been intended for the number 2 Vampire fighter. The replacement engine arrived on December 28 and was promptly installed in the XP-80. The XP-80 was finally ready for its maiden flight.
The first flight of the XP-80 took place on January 8, 1944 with test pilot Milo Burcham at the controls. The first flight had to be cut short after only five minutes because of undercarriage retraction failure and the pilot's concern over boosted aileron sensitivity. These problems were quickly fixed. Subsequent test flights reached a top speed of 502 mph at 20,480 feet, the XP-80 becoming the first USAAF aircraft to exceed 500 mph in level flight. However, the flight tests also disclosed a number of problems including bad stall and spin characteristics, an excessively-high stick force, unsatisfactory fuel management systems, and poor engine reliability and performance. At low speeds, it had a tendency to stall and roll sharply to the right with little or no warning. These problems were addressed one-by-one. The original blunt-tipped wing and tail surfaces were replaced with rounded tips after the fifth flight, and sharp leading edge fillets were added at the wing roots. The tailplane incidence was increased by 1 1/2 degrees.
The XP-80 weighted 6287 pounds empty and 8196 pounds loaded. Dimensions were wingspan 37 feet 0 inches, length 32 feet 10 inches, height 10 feet 3 inches, and wing area 240 square feet. During tests, the XP-80 reached a top speed of 502 mph at 20,480 feet, becoming the first USAAF aircraft to exceed 500 mph in level flight. Service ceiling was 41,000 feet, and initial climb rate was 3000 feet per minute. The aircraft was armed with six 0.50-inch Browning M2 machine guns with 200 rounds per gun.
The XP-80 was eventually transferred to the 412th Fighter Group for tactical evaluation. Following that, the aircraft was returned to Muroc before being assigned to the AAF Training Command at Chanute Field in Illinois. The XP-80 survived all of these evaluation trials, and on November 8, 1946, it was transferred to the Smithsonian Institution for eventual display. Restoration work was completed in May of 1978. I presume that it is now sitting somewhere at the Paul Garber Restoration Facility, awaiting the availability of a suitable location for its display.
XP-80 Serial Number:
44-83020 Lockheed XP-80 Shooting Star c/n 140-1001 Now with National Air and Space Museum