Until the recent boom in the very light jet market, the FJ44 was one of the smallest turbofans available for civilian applications.

Although basically a Williams design, Rolls-Royce was brought into the project at an early stage to design, develop, and manufacture an air-cooled high-pressure (HP) turbine for the engine.

The Williams FJ33 is a newer, smaller engine based on the basic FJ44 design.

In 2005, a new low end version, the FJ44-1AP, was introduced, with a 1,965 lbf (8.74 kN) takeoff thrust.

The bypass duct runs the full length of the engine.