The MiG-17 was not originally designed to function as a fighter-bomber, but in 1971 Hanoi directed that United States Navy warships were to be attacked by elements of the VPAF. This would require the MiG-17 to be fitted with bomb mountings and release mechanisms. Chief Engineer of the VPAF ground crews, Truong Khanh Chau, was tasked with the mission of modifying two MiG-17s for the ground attack role; after three months of work, the two jets were ready. On 19 April 1972, two pilots from the 923rd FR took their bomb laden MiG-17s and attacked the U.S. Navy destroyer and light cruiser . Each MiG was armed with two bombs. Pilot Le Xuan Di managed to hit the destroyer's aft 5" gun mount, destroying it, but inflicting no fatalities, as the crewmen had vacated the turret earlier due to a malfunction with the gun system.