 Hanoi's MiG-17 and MiG-19 interceptors could not deal with those bombers at their flying altitude.In summer 1972 the VPAF was directed to train 12 MiG-21 pilots for the specific mission of attacking and shooting down B-52 bombers, with two-thirds of those pilots specifically trained in the night attack.On 26 December 1972, just two days after tail gunner Albert Moore downed his MiG-21, a VPAF MiG-21MF (number 5121) from the 921st Fighter Regiment, flown by Major Phạm Tuân over Hanoi, claimed the first aerial combat kill of a B-52 Stratofortress.