A close-up of the starboard side of the Royal Navy Fleet Air Arm YF-4K1 (Phantom) prototype aircraft, serial XT595, moving under her own power at the McDonnell Douglas aircraft factory at Saint Louis, Missouri. Her entire nose section, engine intakes and the end of her tailplane are out of the picture. The Rolls Royce logo is on the engine exhaust cowling. The completion to first flight status of the two prototype aircraft for the Royal Navy's Fleet Air Arm was the reason for a press viewing day at the factory. YF-4K1 (serial XT595) first flew 26 June 1966 and left the factory for the Edwards Air Force Base 21 July 1966. YF-4K2 (serial XT596) first flew 30 August 1966.