In 1964, the United States secretly agreed to supply a few B-57Bs to the Vietnamese Air Force. The United States had initially been reluctant to equip the Vietnamese Air Force with jet aircraft, since this would be a technical violation of the Geneva Accords and might further escalate the war. However, the US had already equipped other friendly nations in the region with jet aircraft, and pressure from Saigon coupled with a need to boost the sagging morale of the South Vietnamese people, led to a change of heart.
The first VNAF B-57 crews began training in secret at Clark AFB in the Philippines later in 1964. Later training took place at Tan Son Nhut instead of Clark. One of the students was none other than Nguyen Cao Ky, the commander of the VNAF and later president of the Republic of Vietnam.
On August 1, 1965, the blanket of secrecy was removed and an announcement was made that four B-57 bombers would be provided to the Vietnam Air Force. Four B-57Bs, painted in VNAF insignia, flew past during a formal presentation ceremony held on August 9.
Shortly after the presentation ceremony, a new transition and training program for Vietnamese Air force pilots was started at Clark AB, operating more openly than the first. Two Philippine Air Force navigators were included in the program. The reason for this was strictly political, since this program was officially sponsored by the US State Department and in order for the Philippine government to allow VNAF personnel into their country, they required that two PAF navigators participate in the program. The new program began on September 20. Each pilot was to receive 70 hours in the airplane with no less than 40 training sorties. Navigator training began on October 11.
As the crews completed their training, they went to Da Nang and flew combat missions with the USAF 8th or 13th Bomb Squadrons, whichever happened to be on station at the time. To gain combat experience, each new crewmember flew with an American pilot or navigator, whichever the case may be. Eventually, the VNAF crew members flew in VNAF-marked B-57s, but their combat missions always remained strictly under USAF operational control.
The Vietnamese government felt at this stage that the VNAF B-57 program should be given some more visibility, and to celebrate Vietnamese Armed Forces Day, on October 29, 1965, five B-57s from the 8th Bomb Squadron, then based at Da Nang, were repainted with VNAF insignia and carried out an air strike against a suspected VC stronghold and landed Tan Son Nhut. After landing, the planes took off again and joined other VNAF aircraft in a formation flyover of Saigon. Although manned solely by American crews, this attack was heralded as the introduction of VNAF B-57s into combat.
At this stage, the Vietnamese B-57 training program at Clark began to run into serious morale problems. Vietnamese crews suddenly began to complain of various illnesses, which grounded many trainees and brought their training to a standstill. In addition, on January 8, 1966 a B-57 was destroyed in a training accident, further lowering morale. Some Vietnamese crews flatly stated that they could not physically perform the maneuvers required in the B-57. To make matters even worse, Major Nguyen Ngoc Bien, the leader of the VNAF B-57 program, was killed in a freak ground accident on February 23, 1966 at Da Nang. (It is not exactly certain if this accident took place at Clark Or at Da Nang--the sources differ). The death of Major Bien, who was well-liked and well-respected by both Vietnamese and Americans, resulted in a complete loss of any incentive for the Vietnamese crewmen to stay with the B-57, and from this point on there was very little Vietnamese activity in the B-57 program. On April 20, 1967, the VNAF B-57 operation was formally terminated.