 Believing the design to have commercial potential, Curtiss developed the Model 51 as a civil equivalent powered by the less powerful Curtiss Challenger engine.The company operated 109 of these aircraft in its own air taxi service, the Curtiss Flying Service during the 1930s.A number of these aircraft were experimentally fitted with the same Wright engines used in their military counterparts as the J-1 and J-2, but these were not produced in quantity.