The Curtiss P-3 Hawk was another variant of the basic Curtiss P-1 airframe. The P-3 replaced the in-line vee engine of the P-1 and P-2 with a radial engine. The prototype XP-3 was the last production P-1A (S/N 26-300) initially modified with a Curtiss R-1454 radial engine which was later replaced by a more powerful Pratt & Whitney radial. A P-3 (S/N 28-189) was entered in the 1929 National Air Races and placed second in the Thompson Trophy Race with an average speed of 186.84 mph.