Century Series - McDonnell Douglas F-110A Spectre

For a brief period before the 1962 United States Tri-Service Aircraft Designation System, the McDonnell Douglas F-4 Phantom II was known as the F-110 Spectre in United States Air Force service and F4H by the United States Navy. Both services settled on F-4 Phantom II as the eventual designation for the aircraft.

Note: The United States Air Force also used the designation “YF-110” for MiG-21 and Chinese F-7 aircraft acquired and flown under the Constant Peg program.

via Wikipedia