Tim Forhan's drawing 'F4U 1D Approach' is of an airplane named the 'Corsair Mk IV'. This bomber was built at the same time as the F4U-1C, but was introduced 8 months after the F4U-1C, in April of 1944. This airplane had the new 8W water-injection engine which gave the bomber up to 250 hp more power (increasing speed from 417 mph to 425 mph), thus increasing performance of the aircraft. Because of the United States Navy's demand for fighter-bombers, this airplane carried twice as many rockets as the 1A's and a twin-rack plumbing for an additional belly drop tank. However, due to these changes, rocket tabs were needed and bomb pylons were bolted on the fighter, which caused an extra drag because this aircraft was heavy and not very aerodynamic. This is one of Tim's earlier pencil drawings, but you can see from this image that no details on this aircraft drawing have been left out. This drawing is of the same type of aircraft as his drawing 'F4U 1D Carrier Landing'.