Complex sentence: Bay and his flight commenced to cut off the F-4s, he rolled in behind an F-4 piloted by Major John "Robbie" Robertson and his backseater Hubert Buchanan.
Split into simpler sentences: Bay and his flight commenced to cut off the F-4s. Bay rolled in behind the F-4 of Major John "Robbie" Robertson and his backseater Hubert Buchanan.