The General Electric/Allison J35 was the

United States Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Si ...

's first axial-flow (straight-through airflow) compressor

jet engine A jet engine is a type of reaction engine discharging a fast-moving jet (fluid), jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition can include Rocket engine, rocket, Pump-jet, water jet, and ...

. Originally developed by

General Electric General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable ene ...

(GE company designation TG-180) in parallel with the Whittle-based centrifugal-flow J33, the J35 was a fairly simple

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, a ...

, consisting of an eleven-stage axial-flow compressor and a single-stage turbine. With the

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 c ...

, which most models carried, it produced a thrust of . Like the J33, the design of the J35 originated at General Electric, but major production was by the

Allison Engine Company The Allison Engine Company was an American aircraft engine manufacturer. Shortly after the death of James Allison in 1929 the company was purchased by the Fisher brothers. Fisher sold the company to General Motors, which owned it for most of it ...

Design and development

While developing the T31 axial

turboprop A turboprop is a turbine engine that drives an aircraft propeller. A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. ...

in 1943

realized that they had the resources to design an axial flow

at the same time as their centrifugal-flow J33 engine. They recognized the axial would have more potential for the future and went ahead with the TG-180 engine. GE axial compressor designs were developed from the

NACA The National Advisory Committee for Aeronautics (NACA) was a United States federal agency founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its assets ...

8-stage compressor. GE-Allison-J35-Engine

The engine had its starter and accessories (fuel control, fuel pump, oil pumps, hydraulic pump, RPM generator) mounted in the center of the compressor inlet. This accessory layout, as used on centrifugal engines, restricted the area available for compressor inlet air. It was carried over to the

J47 The General Electric J47 turbojet (GE company designation TG-190) was developed by General Electric 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. I ...

but revised (relocated to an external gearbox) on the J73 when a increase in airflow was required. It also had an inlet debris guard which was common on early jet engines. GE developed a variable

for the engine, although electronic control linked with engine controls had to wait until the J47. Marrett describes one of the potential consequences of manual control of the engine and afterburner on an turbine engine: if the afterburner lit but the pilot failed to ensure the nozzle opened, the RPM governor could overfuel the engine until the turbine failed.

Operational history

The General Electric J35 first flew in the Republic XP-84 Thunderjet in 1946. Late in 1947, complete responsibility for the development and production of the engine was transferred to the Allison Division of the General Motors Corporation and some J35s were also built by GM's

Chevrolet Chevrolet ( ), colloquially referred to as Chevy and formally the Chevrolet Motor Division of General Motors Company, is an American automobile division of the American manufacturer General Motors (GM). Louis Chevrolet (1878–1941) and ou ...

division. More than 14,000 J35s had been built by the time production ended in 1955. The J35 was used to power the Bell X-5 variable-sweep research aircraft and various prototypes such as the

Douglas XB-43 Jetmaster The Douglas XB-43 Jetmaster is an American 1940s jet-powered prototype bomber. The XB-43 was a development of the XB-42, replacing the piston engines of the XB-42 with two General Electric J35 engines of 4,000 lbf (17.8 kN) thrust ea ...

, North American XB-45 Tornado,

Convair XB-46 The Convair XB-46 was a single example of an experimental medium jet bomber which was developed in the mid-1940s but which never saw production or active duty. It competed with similar designs, the North American XB-45 and Martin XB-48, all of w ...

, Boeing XB-47 Stratojet,

Martin XB-48 The Martin XB-48 was an American medium jet bomber developed in the mid-1940s. It competed with the Boeing B-47 Stratojet, which proved to be a superior design, and was largely considered as a backup plan in case the B-47 ran into development p ...

, and Northrop YB-49. It is probably best known, however, as the engine used in two of the leading fighters of the

(USAF) in the 1950s: the

Republic F-84 Thunderjet The Republic F-84 Thunderjet was an American turbojet fighter-bomber aircraft. Originating as a 1944 United States Army Air Forces (USAAF) proposal for a "day fighter", the F-84 first flew in 1946. Although it entered service in 1947, the Thun ...

and the

Northrop F-89 Scorpion The Northrop F-89 Scorpion was an American all-weather, twin-engined interceptor aircraft built during the 1950s, the first jet-powered aircraft designed for that role from the outset to enter service. Though its straight wings limited its per ...

. A largely redesigned development, the J35-A-23, was later produced as the

Allison J71 The Allison J71 was a single spool turbojet engine, designed and built in the United States. It began development in 1948 as a much modified J35, originally designated J35-A-23. Operational history The Allison J71 turbojet powered the Douglas B ...

, developing thrust.

Variants

''Data from:''Aircraft engines of the World 1953, Aircraft engines of the World 1950 ;J35-GE-2: thrust, prototypes built by

. ;J35-GE-7: thrust, built by

, powered the 2 Republic XP-84 Thunderjet prototypes ;J35-GE-15: thrust, built by

, powered the sole Republic XP-84A Thunderjet ;J35-A-3: thrust ;J35-C-3: thrust, production by

. ;J35-C-3: thrust, production by

. ;J35-A-4: Similar to -29, thrust ;J35-A-5: thrust ;J35-A-9: thrust ;J35-A-11: Similar to -29, thrust ;J35-A-13: thrust ;J35-A-13C: ;J35-A-15: Similar to -29, thrust, powered the 15 Republic YP-84 Thunderjets ;J35-A-15C: thrust ;J35-A-17: Similar to -29, thrust ;J35-A-17A: Similar to -29, thrust ;J35-A-17D: thrust ;J35-A-19: Similar to -17, thrust ;J35-A-21: Similar to -35, thrust, with afterburner ;J35-A-21A: Similar to -35, thrust, with afterburner ;J35-A-23: Similar to -29, thrust, original designation for the

;J35-A-25: Similar to -29, thrust ;J35-A-29: thrust ;J35-A-33: Similar to -35, thrust, with afterburner, without anti-icing ;J35-A-33A: Similar to -35, thrust, with afterburner, without anti-icing ;J35-A-35: thrust, with afterburner ;J35-A-41: Similar to -35, thrust, with afterburner, with anti-icing ;Model 450:company designation for J35 series engines. ;General Electric 7E-TG-180-XR-17A : ca gas power, gas generator for the

Hughes XH-17 The Hughes XH-17 "Flying Crane" was the first helicopter project for the helicopter division of Hughes Aircraft Company. The XH-17, which had a two-bladed main rotor system with a diameter of 134 feet (41 m), still holds the world record for fl ...

Applications

* Bell X-5 * Boeing XB-47 Stratojet *

Douglas D-558-1 Skystreak The Douglas Skystreak (D-558-1 or D-558-I) was an American single-engine jet research aircraft of the 1940s. It was designed in 1945 by the Douglas Aircraft Company for the U.S. Navy Bureau of Aeronautics, in conjunction with the National Advis ...

Fiat G.80 The Fiat G.80 was a military jet trainer developed in Italy in the 1950s, and was that country's first true jet-powered aircraft. It was a conventional low-wing monoplane with retractable tricycle undercarriage and engine air intakes on the fus ...

(proposal only) *

(experimental helicopter) *

North American FJ-1 Fury The North American FJ-1 Fury was the first operational jet aircraft in United States Navy service, and was developed by North American Aviation as the NA-135.North American XB-45 Tornado * North American XP-86 Sabre *

* Northrop YB-49 *

* Vought F7U-3 Cutlass (interim test usage)

Engines on display

* Allison J35 is on public display at Texas Air Museum - Stinson Chapter,

San Antonio ("Cradle of Freedom") , image_map = , mapsize = 220px , map_caption = Interactive map of San Antonio , subdivision_type = Country , subdivision_name = United States , subdivision_type1= State , subdivision_name1 = Texas , subdivision_ ...

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

Design and development

Operational history

Variants

Applications

Engines on display

Specifications (J35-A-35)

See also

References

Further reading