The F4U was arguably the finest propeller-driven fighter on the Allied side. It was the first single-engine American fighter to break 400 miles per hour in level flight. It was first driven by a Pratt & Whitney Double Wasp engine of 1800 horsepower, about as powerful as they could get at the time. Vought simply built the smallest airframe they could around the huge radial engine. To maximize performance, a 13-foot Hamilton Standard Propeller was used. It was originally designed to be operated from an aircraft carrier but the US Navy decided it was unsuitable for precise landings and take offs, so they handed it over to the Marines for land-based use. It proved highly successful both as a fighter and in the ground attack role. It continued in use as an attack airplane through the Korean war, and the last Corsair was produced in 1953.