from the beginning of "freedom train" in april to the end of june 1972 the united states lost 52 aircraft over north vietnam: 17 to missiles; 11 to anti-aircraft weapons; three to small arms fire; 14 to migs; and seven to unknown causes. during the same time period, the vnaf lost ten aircraft. 63 north vietnamese aircraft were destroyed during the same time period. north vietnam claimed that it had shot down 651 aircraft and sunk or set on fire 80 u.s. warships during the operation.