The Williams FJ33 is a family of turbofan jet engines intended for use in very light jet aircraft. The FJ33 is a scaled-down version of the FJ44 engine.
Engine configuration is believed to be a single stage fan, with booster stage/s, driven by a 2 stage LP turbine, supercharging a centrifugal HP compressor, driven by a single stage HP turbine. An annular combustor is featured.
The FJ33 has a dry weight of less than 300 lb (140 kg), overall diameter of 21.05 in (535 mm), 47.9 in (1,220 mm) overall length, and produces between 1,000 lbf (4,400 N) and 1,800 lbf (8,000 N) static thrust. Specific fuel consumption at 1,200 lbf (5,300 N) thrust (SLS, ISA) is understood to be 0.486 lb/(lbf·h) (13.8 g/(kN·s)).