How big is the Williams FJ33?
The FJ33 has a dry weight of less than 300 lb (140 kg), overall diameter of 18. N) and 1,800 lbf (8,000 N) static thrust. The bypass ratio of the FJ33-5A is about 3. High bypass ratios give you more static thrust and better efficiency but lose thrust more quickly as true airspeed increases (which, in a jet, means as you climb to altitude).