Although America’s first jet fighter began its life near the beginning of the war, a series of difficulties prevented it from seeing combat.
“Icons of Aviation History” is a diary series that explores significant and historic aircraft.
The American jet fighter program is a direct outgrowth of the British efforts led by Frank Whittle. Until Whittle’s W.1 turbojet engine made its first successful flight in May 1941, virtually no work had been done in the US on jet engines. So when Army Air Corps Major General Hap Arnold was invited by the British to observe the flight, he was stunned.
The US had not yet entered the war, but was already deeply committed to England as an ally and was providing aid in the form of Lend-Lease, so the British felt comfortable in sharing the super-secret discovery with the Americans. Copies of both the engine and the design drawings were dispatched to the US onboard a B-24 and, under the strictest secrecy, the General Electric Company was assigned to produce their own version of the Whittle engine (known as the I-A) under the codename of “Type I Supercharger”, and Bell Aircraft was given the task of producing an airframe to be used as a testbed for it. (Bell was selected mostly because its P-39 fighter was no longer in production, so the company did not have the previous commitment of resources that the other aircraft manufacturers had.) The result was the Bell P-59 Airacomet program. The airframe was a hastily-upgraded version of a previous design for a twin-engined prop fighter: Bell enlarged the airframe, strengthened it, and moved the engines to the wing roots, running alongside the fuselage. It was given the codename “Model 27”.
The first flight tests with Whittle’s design, in October 1942, did not meet expectations. So GE went back to the lab and made some modifications that increased the thrust of the I-A engine by 15% to 1250 pounds. This new version was called the I-16, and was eventually designated the J-33. But when the J-33 was flight-tested in the summer of 1943, it was still not meeting its planned specs.
The National Advisory Committee on Aeronautics (one of the forerunners of what would decades later become NASA) had already set up a committee to study possible new technologies in aircraft propulsion, and had begun construction of a lab next to the Cleveland Municipal Airport, to be called the Aircraft Engine Research Laboratory (AERL). For reasons of military secrecy, NACA had not been told about the Whittle jet engine, but now the Army Air Corps decided that it needed their help, and in July 1943 a selected team of NACA researchers were briefed about the top-secret device and provided with engineering drawings. It was decided that the AERL would be dedicated solely to jet experiments as soon as it was completed, and in September the newly-finished lab was given the established cover name of the “Supercharger Building” to disguise the true nature of its secret research.
Testing of the I-A and J-33 engines began immediately: there were test runs over a wide range of temperatures and air pressures to simulate different altitudes, and tinkering produced some changes in the design that resulted in gains in thrust. Within a few months, GE had produced the I-40 engine. When the lab’s fullsize wind tunnel began operations in January 1944, Bell engineers began experiments on models of the P-59 to test various shapes and configurations.
The US Navy, meanwhile, was also interested in jet engines, but was far more cautious than the Army due to the stringent requirements for taking off and landing from carriers. So in 1943 the Navy tasked the Ryan Aircraft Company to design an airplane that could utilize both a standard piston-propeller engine and a turbojet. This resulted in the XFR-1, an experimental plane that was able to take off and land from a carrier using a Wright R-1820 radial engine in the nose, but which could also switch in flight to an I-16 jet engine in the tail when it needed a burst of speed. The Navy hoped to get a carrier-based interceptor that would be fast enough to catch Japanese kamikaze planes before they could reach their targets.
Test flights of the “Ryan Fireball” began in June 1944. The first three prototypes were all lost in crashes, which were determined to have been cause by wing rivets that were too weak to withstand the stress. These were doubled in strength, and the Navy officially ordered 700 FR-1 Fireball fighters, to be delivered beginning in March 1945. As it turned out, only 66 had been sent to the Navy before the war ended in August, and none of those were ever deployed.
The Army, meanwhile, was flying nine test versions of the P-59. The original designs were now designated P-59A, and the newer versions, with engines of 2000 pounds thrust, were P-59B. Most of the test flights were carried out at the remote Muroc dry lakebed in Death Valley. Whenever the planes were near people, they wore fake propellers on their nose to disguise them.
While GE had at last gotten the jet engines working up to specs, the rather simple airframe, combined with the low thrust-to-weight ratio of the engines, led to aerodynamic problems, and the P-59 had trouble reaching 400mph, a speed that piston-engined fighters like the P-47 were already routinely exceeding. As a result, plans to equip the P-59 with 20mm cannons and put it into production were shelved, and it became treated as simply an engine testbed. By the time the war ended in August 1945, Bell had produced 66 of the experimental aircraft in total. One of these was traded to the UK for a Gloster Meteor fighter, but after flying it a few times the British realized that it was far inferior to the Gloster and sent it back to the US.
Six P-59 Airacomets are on display. One of these is a P-59A in the Smithsonian Air and Space Museum, and the US Air Force Museum exhibits a P-59B. There is also a P-59B at the Planes of Fame Museum in Chino CA.
NOTE: As some of you already know, all of my diaries here are draft chapters for a number of books I am working on. So I welcome any corrections you may have, whether it's typos or places that are unclear or factual errors. I think of y'all as my pre-publication editors and proofreaders. ;)