Today, the jet age truly turns 65 years old. It was born when the prototype XP-84 Thunderjet flew for the first time at Muroc Army Airfield on this day in 1946. Current jets are far more powerful than the first jet, they fly faster, farther, and higher; and Muroc is no longer under control of the Army, it is now Edwards Air Force Base.
Originally, the engineers and designers at Republic simply thought of installing a turbojet engine in their P-47 Thunderbolt design. This idea, however economical, proved unfeasible. The Thunderbolt airframe turned out to be an inadequate host for the jet engine. The lead designer at Republic, Alexander Kartveli, directed his team to start designing an original aircraft. This work first began in 1944, even before the end of the war.
The XP-84 was terribly underpowered, as were all the first jets of the new jet age. The Thunderjet consisted of one seat, one engine, and limited provisions for armament and weapons. On the first airplanes, the engine was of dubious character, with a full operational lifetime of only 40 hours. Another problem of the J-35-GE-15 engines was a lack of power—they produced only 3745 pounds of thrust.
After the National Security Act of 1947 created the United States Air Force, the military services eliminated the “P” designation for pursuit aircraft replacing it with the “F” designation for fighter. Late that same year, the 14th Fighter Group of Bangor, ME became operational with the new F-84B fighter.
From the start, the airplane had problems. Like all new technology, the pilots and technicians had to learn this new system. At first, because of wrinkling in the fuselage skins, the Air Force limited the operational loading of the airplane to 5.5 g’s. Moreover, due to problems with the phenomenon of control reversal, the Air Force set the maximum speed at .8 Mach. The airplane obviously had more growing pains to work through, but before Republic could accomplish their work with redesigning the airplane, the Air Force grounded the entire fleet of F-84Bs.
Republic further refined the airplane developing it into the F-84E. When the E-model became operational, it was a tougher airframe with a more powerful engine. The F-84 served the Air Force well in Korea, in roles of interdiction, escort, and ground support.
The F-84 was also the first operational jet to have aerial refueling capability. It was also the first airplane flown by the Air Force demonstration team, the Thunderbirds. When the airplane reached the G-model variant, it was the first fighter equipped with swept wings.
While the airplane was not as glorious as some of the more famous jets that followed, the Thunderjet’s place in aviation history proved more important in teaching the aeronautical engineers, pilots, and technicians about jets. The aviation industry learned a great deal about jet aviation because of this one aircraft.
The Thunderjet later became the F-84F Thunderflash, which remained actively flying with the Air National Guard until 1971. The last of the F-84s flying operationally was with the Hellenic Air Force as late as 1991.
© 2011 J. Clark