Linebacker II: How Many B-52s Were Shot Down In The Vietnam ‘Christmas Bombing’ Campaign?

Operation Lineback II took place at the end of 1972 and was an enormous B-52 Stratofortress-led bombing campaign over North Vietnam. On one dark day for the United States Air Force, an unprecedented six B-52s were lost over North Vietnam. During the operation, American aviators claimed to have shot down two Vietnamese MiG-21s with their tailguns (the last time bombers machine-gunned down fighters). Meanwhile, Vietnam claims to have shot down two B-52s in air-to-air combat with MiG-21s (which would be the only time a fighter shot down a B-52). But how many B-52s were lost in total over the multiday campaign?