United States military F4U Corsair flying in Maryland

The F4U incorporated the largest engine available at the time, the 2,000 hp (1,490 kW) 18-cylinder Pratt & Whitney R-2800 Double Wasp radial. To extract as much power as possible, a relatively large, 13 feet 4 inches (4.1 m) Hamilton Standard Hydromatic three-blade propeller was used. To accommodate a folding wing, the designers considered retracting the main landing gear rearward, but for the chord of wing selected, it was difficult to fit undercarriage struts long enough to provide sufficient clearance for the large propeller. Their solution was an inverted gull wing, a similar layout to the one used by Germany's Junkers Ju 87 dive bomber, considerably shortening the length of the main gear legs.