Model Variants (Including Prototypes)
Model 83 - Original model with R-1340-8 engine of 425 horsepower; single example.
Model 89 - Provision for 500lb bomb rank under fuselage; single example.
P-12 (Model 102) - USAAC evaluation model of F4B-1; R-1340-7 engine of 450 horsepower; nine produced.
XP-12A - Single-example; NACA engine cowl with R-1340-9 engine of 525 horsepower.
P-12B - Based on P-12 with revised landing wheels; 90 examples produced.
P-12C - Ring engine cowl; spead-bar undercarriage; 96 examples produced.
P-12D - P-12C model with R-1340-17 engine of 525 horsepower; 35 produced.
P-12E - P-12D model with semi-monocoque fuselage structure; new vertical tail fin; production included versions with tail wheel over skid design; 100 examples.
P-12F - P-12E model with R-1340-19 engine of 600 horsepower; 25 examples.
Xp-12G - Single prototype example; fitted with R-1340-15 engine with side-mounted supercharger.
XP-12H - Single prototype example; fitted with GISR-1340E engine.
P-12J - P-12E with R-1320-23 engine of 575 horsepower; special bomb sighting equipment; single example.
YP-12K - P-12E and P-12J models with fuel-injected SR-1340E series engines; seven examples converted from existing mounts.
XP-12L - Single experimental example based on YP-12K fitting F-2 supercharger.
XF4B-1 - US Navy prototypes; two examples
F4B-1 - Initial US Navy models; provision for underfuselage bomb; 27 examples produced.
F4B-2 - Spread-bar landing gear; tailwheel; 46 produced.
F4B-3 - F4B-2 models with semi-monocoque fuselage; 21 examples.
F4B-4 - F4B-3 model with new tail fin design; fitted with R-1340-16 engine of 550 horsepower; provision for 2 x 116lb bombs.
F4B-4A - 23 examples serving as radio-controlled targets.
Model 100 - Civilian variant based on F4B-1; four produced.
Model 100A - Two-seat conversion manufactured for Howard Hughes.
Model 100D - Demonstrator aircraft
Model 100E - P-12E model for export to Siamese Air Force.
Model 100F - P-12F engine testbed for Pratt & Whitney.
Model 218 - P-12E model for export to China
Model 256 - F4B-4 model for export to Brazil; 14 examples.
Model 267 - F4B-3 model (P-12E wings) for export to Brazil; nine examples.
A-5 - Proposed radio-controlled target drone; never produced.