Check the Wikipedia entry for the F9F:-
"This combat is little-known due to the involvement of the US (NSA) – the existence of which was then top secret – in planning the mission; the MiGs were intercepted as a result of intelligence provided by the NSA. After losing contact with his wingman, Williams was alone in a dogfight with six MiG-15s; after landing on Oriskany, his Panther had 263 hits by cannon shells or fragments, and was beyond repair."