"Bluejay 4" was the call sign of an American F-104 Starfighter interceptor, registry FG-914, that was in service with the United States Air Force in the mid-20th century. This airplane was piloted by Captain John Christopher in July 1969.
In that year, Bluejay 4 was scrambled to intercept and investigate an apparent UFO contact in 1969. The "UFO" was actually the USS Enterprise, which had accidentally been thrown back in time. Spock warned Captain Kirk that the closing aircraft may be equipped with nuclear warheads and could pose a real threat. Kirk used the tractor beam to hold the aircraft off, but due to the fragility of the jet, it began to break up under the force of the tractor beam. As a result, Kirk ordered its pilot beamed aboard the Enterprise. Christopher was saved, but the aircraft was demolished. Its wreckage fell back to Earth and landed in southern Nebraska. The flight recorder and footage from the wing cameras were taken to the 498th Air Base in Nebraska to be processed. (TOS: "Tomorrow is Yesterday")