The General Electric J47

turbojet The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, and ...

(GE company designation TG-190) was developed by

General Electric General Electric Company (GE) was an American Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1892, incorporated in the New York (state), state of New York and headquartered in Boston. Over the year ...

from its earlier J35. It first flew in May 1948. The J47 was the first axial-flow turbojet approved for commercial use in the United States. It was used in many types of aircraft, and more than 30,000 were manufactured before production ceased in 1956. It saw continued service in the US military until 1978.

Packard Packard (formerly the Packard Motor Car Company) was an American luxury automobile company located in Detroit, Michigan. The first Packard automobiles were produced in 1899, and the last Packards were built in South Bend, Indiana, in 1958. One ...

built 3,025 of the engines under license. The J47's greatest advantage, as advertised, was its array of features which were unavailable and unprecedented in any other engine. It was advertised as an 'all-weather engine' due to its anti-icing systems which allowed it to perform at high altitudes and extreme temperatures where other aircraft's performance suffered. Its development began without an explicit need for it, although this design was quickly purchased by the military for its many potential benefits. In 1978, J47s were formally withdrawn from active military duty when the Air National Guard retired the jet-boosted KC-97Js. Despite this, these engines are still extensively utilized in F-86 Sabre jets owned by civilians, making them a common sight at air shows.

Design and development

The J47 design used experience from the TG-180/J35 engine which was described by ''

Flight Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...

'' magazine in 1948 as the most widely used American-conceived turbojet. The

featured a revolutionary anti-icing system where hollow frame struts allowed heated airflow to pass through from the

compressor A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor. Many compressors can be staged, that is, the gas is compressed several times in steps o ...

, allowing fighter jets equipped with the engine to function at high altitudes, and in cold conditions such as the top of Mount Washington in New Hampshire's White Mountains, where the engine was first tested. The engine featured an electronically controlled

afterburner An afterburner (or reheat in British English) is an additional combustion component used on some jet engines, mostly those on military supersonic aircraft. Its purpose is to increase thrust, usually for supersonic flight, takeoff, and combat ...

, a system that dumped additional fuel into the

combustor A combustor is a component or area of a gas turbine, ramjet, or scramjet engine where combustion takes place. It is also known as a burner, burner can, combustion chamber or flame holder. In a gas turbine engine, the ''combustor'' or combustion ...

pipe 'behind' the engine, reheating the exhaust and producing significantly more thrust, although with greatly reduced efficiency and high fuel burn rates. The engine production process in the Lockland facility (renamed to the Evendale facility) utilized vertical engine assembly to ensure compressor rotor balance and stability. The technological jump provided by the engine led to it becoming the most produced jet engine in aviation history, and established

GE Aviation General Electric Company, doing business as GE Aerospace, is an American aircraft engine supplier that is headquartered in Evendale, Ohio, outside Cincinnati. It is the legal successor to the original General Electric Company founded in 1892, wh ...

as a worldwide leader in jet propulsion. Overhaul life for the J47 ranged from 15 hours (in 1948) to a theoretical 1,200 hours (625 achievable in practice) in 1956. For example, the J47-GE-23 was rated to run 225 hours

time between overhaul Time between overhauls (abbreviated as TBO or TBOH) is the manufacturer's recommended number of running hours or calendar time before an aircraft engine or other component requires overhaul. On rotorcraft, many components have recommended or ma ...

s. As installed on the F-86F, it experienced one in-flight shutdown every 33,000 hours in 1955 and 1956.

Variants

;J47-GE-1:(TG-190A) thrust. ;J47-GE-2: (TG-190E) at 7,950 rpm, powered the North American FJ-2 Fury ;J47-GE-3:(TG-190A) thrust. ;J47-GE-7:(TG-190B) thrust. ;J47-GE-9:(TG-190B) thrust. ;J47-GE-11:(TG-190C) Powered the Boeing B-47A and B-47B ;J47-GE-13:(TG-190C) Powered the

North American F-86E Sabre The North American F-86 Sabre, sometimes called the Sabrejet, is a transonic jet fighter aircraft. Produced by North American Aviation, the Sabre is best known as the United States' first swept-wing fighter that could counter the swept-wing So ...

& North American B-45C tornado ;J47-GE-15: (7E-TG-190C) Powered the North American B-45C tornado ;J47-GE-17: (7E-TG-190D) at 7,950 rpm dry, at 7,950 rpm wet, powered the North American F-86D Sabre ;J47-GE-17B: thrust ;J47-GE-19:(TG-190C) , powered the Convair B-36D & B-36F ;J47-GE-23: (7E-TG-190E) , powered the Boeing B-47B and RB-47B ;J47-GE-25: thrust dry, ( with water injection), powered the Boeing B-47E and RB-47E ;J47-PM-25: (TG-190E) Production by Packard Motor Car Company ;J47-ST-25: (TG-190E) Production by Studebaker Corp. ;J47-GE-27: (TG-190E) thrust, powered the North American F-86F Sabre ;J47-GE-29: (TG-190E) Similar to -27 ;J47-GE-33: thrust, powered the F-86F & F-86K

Applications

Boeing B-47 Stratojet The Boeing B-47 Stratojet (Boeing company designation Model 450) is a retired American long- range, six-engined, turbojet-powered strategic bomber designed to fly at high subsonic speed and at high altitude to avoid enemy interceptor aircraft ...

* Boeing KB-50J Superfortress *

Boeing KC-97 Stratofreighter The Boeing KC-97 Stratofreighter is a four-engined, piston-powered United States strategic tanker aircraft based on the Boeing C-97 Stratofreighter. It replaced the KB-29 and was succeeded by the Boeing KC-135 Stratotanker. Design and developme ...

* Chase XC-123A *

Convair B-36 Peacemaker The Convair B-36 "Peacemaker" is a strategic bomber built by Convair and operated by the United States Air Force (USAF) from 1949 to 1959. The B-36 is the largest mass-produced piston-engined aircraft ever built, although it was exceeded in spa ...

* Convair NB-36 * Curtiss XF-87 Blackhawk *

Martin XB-51 The Martin XB-51 was an American trijet ground-attack aircraft. It was designed in 1945 and made its maiden flight in 1949. It was originally designed as a bomber for the United States Army Air Forces under specification V-8237-1 and was designa ...

* North American B-45 Tornado *

North American F-86 Sabre The North American F-86 Sabre, sometimes called the Sabrejet, is a transonic jet fighter aircraft. Produced by North American Aviation, the Sabre is best known as the United States' first swept-wing fighter that could counter the swept-wing Sov ...

* North American F-86D Sabre * North American FJ-2 Fury * Republic XF-91 Thunderceptor Ground-based vehicles that used the engine include: * Spirit of America * M-497 Black Beetle jet-powered railcar

Nuclear-powered X39

In the 1950s, interest in the development of nuclear-powered aircraft led GE to experiment with two nuclear-powered gas turbine designs, one based on the J47, and another new and much larger engine called the X211. The design based on the J47 became the X39 program. This system consisted of two modified J47 engines which, instead of combusting jet fuel, received their heated, compressed air from a heat exchanger that was part of the Heat Transfer Reactor Experiment (HTRE) reactor. The X-39 was successfully operated in conjunction with three different reactors, the HTRE-1, HTRE-2 and HTRE-3. Had the program not been cancelled, these engines would have been used to power the proposed Convair X-6.

Specifications (J47-GE-25)

References

* * * http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%200590.html

External links

Globalsecurity.org – J47
{{USAF gas turbine engines J47 1940s turbojet engines