Chance Vought F4U-1D Corsair was a fighter-bomber version of the F4U-1 series. In early 1944, bomb racks for the F4U-1 were developed by personnel of VMF-222 and VF-17. The modification was rapidly applied by other squadrons. The F4U-1D was powered by a R-2800-8W engine with water injection. The more powerful engine of this model made it possible to carry the extra weight of bombs/tanks and rockets. The F4U-1D had three pylons, one on the centerline and two on the wings. Later small stubs on the outer wing panels, to carry rockets, were added. Also in early 1944, longer oleos were installed in the main landing gear legs. They cured much of the tendency of the Corsair to "bounce". A longer tail wheel leg raised the fin, and reduced the directional stability problem. These improvements were essential in making the Corsair suitable for carrier operations, and in April 1944 the Corsair was finally qualified for carrier operations. Interestingly, all F4U-1D aircraft were painted overall Gloss Sea blue. None saw any action prior to early 1945 when they were part of the task group that made the first carrier borne attacks on Japan since Colette’s raid of 1942. As with most late war aircraft, the F4U-1D soldiered on postwar until replaced the F4U-4 or some other aircraft. Some F4U-1Ds were overhauled and sold to El Salvador in the 1960s.