General Electric J85

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The General Electric J85 is a small single-shaft turbojet engine, capable of generating up to 2,950 lbf (18 kN) of dry thrust or more, with an afterburner. It has an axial-flow compressor with 8 stages (the J85-21 variant added a stage ahead of the base 8 stage compressor for a total of 9 stages). It is one of GE's most successful and longest in service military jet engines.

It was originally designed for the USAF's McDonnell ADM-20 Quail decoy missile

It would subsequently be used on small jet aircraft, such as the Canadair CT-114 Tutor jet trainer, and Cessna A-37 Dragonfly light attack fighter.

The engine is also used on civilian business jets such as the Learjet 23 and the Hamburger Flugzeugbau HFB-320 Hansa Jet under the designation General Electric CJ610. A version of it is used in the Scaled Composites White Knight aircraft, the carrier for the Scaled Composites SpaceShipOne spacecraft. An additional variant, the CF700 is a turbofan with a unique "flade" design in which the rear mounted fan blade is connected directly to the low-pressure turbine blade.

Afterburning variants can reach up to 5,000 lbf (22 kN). Used in the T-38 Talon and F-5 Freedom Fighter, they enabled building a much smaller and lighter supersonic fighter than was possible with other engines. The F-5, made possible by this engine, would be the starting point for the Hornet series of naval fighters. The J85 engine has the highest thrust to weight ratio of any production turbojet in the world. The engine, depending upon additional equipment and specific model, weighs between 300 to 500 pounds.

At full throttle at sea level, this engine, without afterburner, consumes approximately 400 gallons of fuel per hour. At cruise altitude and power, it consumes approximately 100 gallons per hour.

The U.S. Air Force plans to be using the J85 in aircraft through 2040.