(Da Nang, South Vietnam, 29 Mar 1975) - In 1975, the communists of North Vietnam launched a military offensive in the South, which became known as the Ho Chi Minh Campaign.
The Army of the Republic of Vietnam (ARVN) unsuccessfully attempted a defence and a counterattack. It had few remaining operational tanks and artillery pieces, as well as a shortage of spare parts, and ammunition.
The People's Army of North Vietnam (NVA) had a vastly greater supply of new equipment and ammunition.
As a consequence, South Vietnamese President Nguyễn Văn Thiệu was forced to withdraw key army units from the Central Highlands region, which exacerbated an already-perilous military situation and undercut the confidence of the ARVN soldiers in their leadership.
The retreat became a rout. Cities in South Vietnam - Huế, Da Nang and Da Lat in central Vietnam - quickly fell, and the North Vietnamese advanced southwards. As the military situation deteriorated, ARVN troops started deserting en masse.
Thiệu requested aid from US President Gerald Ford, but the US Senate would not release extra money to provide aid to South Vietnam, and had already passed laws to prevent further involvement in Vietnam.
In desperation, Thiệu recalled Nguyễn Cao Kỳ from retirement as a military commander, but resisted calls to name his old rival prime minister.
On the morning of 29 Mar 1975, 2 World Airways Boeing 727s flew from Saigon to Da Nang in an attempt to pick up more refugees. When the first 727 landed at Da Nang Air Base, it was mobbed, 270 people pushed into the plane, all but 3 were from ARVN.
As the aircraft attempted to take off it was hit by a grenade which jammed the flaps and the main runway was blocked by trucks and the pilot instead took off from a taxiway.
A number of ARVN personnel hung onto the undercarriage and in the wheel wells, preventing the retraction of the landing gear, 4 of them survived the flight back to Saigon.
The PAVN entered the outskirts of Da Nang by mid-morning on 29 Mar 1975 and by the afternoon were in complete control of the city.
On 7 Apr 1975, the first VPAF transport aircraft began landing at Da Nang AB to support PAVN operations further south.
In mid-April 1975, the VPAF formed the Quyet Thang ("Determined to Win") Squadron at Da Nang Air Base and began preliminary training of pilots on captured VNAF A-37s, the squadron would carry out the Bombing of Tan Son Nhut Air Base on 28 Apr 1975.