When South Vietnam was overrun by NVA forces on 30 April 1975, approximately 877 aircraft were captured by the communists. Of that number, 87 were reported as F-5As and 27 were F-5Es. In November of that year the Soviets were offered the opportunity to select from the captured U.S. equipment. The Soviets quickly loaded one complete F-5, along with two complete spare engines, any and all spare parts, and all ground support equipment onto a waiting Soviet cargo ship. Several of the F-5s left over from the Vietnam War were sent to Poland, Czechoslovakia, and then Soviet Union, for advanced study of U.S. aviation technology, while others were decommissioned and put on display at museums in Vietnam. The 935th Fighter Regiment of the VPAF 372nd Air Division was the only unit in the world flying both MiG-21 and F-5 fighters. Eventually, the lack of spare parts grounded all the captured aircraft, but in May 2017 it was reported that Vietnam is considering refurbishing some of these aircraft and putting them back into service.