[1]: 123 In 1961, the government of South Vietnam requested the U.S. Military Assistance Advisory Group (MAAG) to plan for expansion of the Tan Son Nhut airport.

[2]: 251 In late 1951, the French Air Force established the RVNAF 312th Special Mission Squadron at Tan Son Nhat Airfield equipped with Morane 500 Criquet liaison aircraft.

Operating under each DASC were numerous Tactical Air Control Party (TACPs), manned by one or more RVNAF/USAF personnel posted with the South Vietnamese Army (ARVN) ground forces.

Observation aircraft also from Tan Son Nhut completed almost 700 reconnaissance sorties, with RVNAF pilots flying O-1 Bird Dogs and U-17 Skywagons.

The technical assistance provided by the personnel of the DAOs and by civilian contractors was essential to the RVNAF, however, because of the cease-fire agreement, the South Vietnamese could not be advised in any way on military operations, tactics or techniques of employment.

This was demonstrated at the fighting around Pleiku, An Lộc and Quảng Trị where the ARVN would have been defeated without continuous air support, mainly supplied by the USAF.

As part of the Paris Peace Accords, a Joint Military Commission was established and VC/PAVN troops were deployed across South Vietnam to oversee the departure of US forces and the implementation of the ceasefire.

[12] Numerous violations of the Paris Peace Accords were committed by North Vietnamese beginning almost as soon as the United States withdrew its last personnel from South Vietnam by the end of March 1973.

[13]: 24  On 4 April a C-5A aircraft carrying 250 Vietnamese orphans and their escorts suffered explosive decompression over the sea near Vũng Tàu and made a crash-landing while attempting to return to Tan Son Nhut; 153 people on board died in the crash.

Airborne troops were sent in for one last attempt to hold the airfield, but the defenders were finally overrun on 16 April and Phan Rang Air Base was lost.

[13]: 72 At 03:58 on 29 April, C-130E, #72-1297, flown by a crew from the 776th Tactical Airlift Squadron, was destroyed by a 122 mm rocket while taxiing to pick up refugees after offloading a BLU-82 at the base.

The ARVN 3rd Task Force, 81st Ranger Group commanded by Major Pham Chau Tai defended Tan Son Nhut and they were joined by the remnants of the Loi Ho unit.

The PAVN 10th Division ordered eight more tanks and another infantry battalion to join the attack, but as they approached the Bay Hien intersection they were hit by an airstrike from RVNAF jets operating from Binh Thuy Air Base which destroyed two T-54s.

[1]: 276 In March 1962 a C-54 Skymaster outfitted for infrared reconnaissance arrived at the base and remained until February 1963, when it was replaced by a Brave Bull Boeing C-97 Stratofreighter.

Bombing missions against the North required a large amount of photographic reconnaissance support, and by the end of 1967, all but one of the Tactical Air Command RF-101C squadrons were deployed to Southeast Asia.

The Detachment flew nighttime reconnaissance missions to identify VC base camps, small arms factories, and storage and training areas.

[24]: 254 On 20 December 1964 Military Assistance Command, Vietnam (MACV) formed the Central Target Analysis and Research Center at the base as a component of its J-2 Intelligence staff branch to coordinate Army and USAF infrared reconnaissance.

[1]: 245 On 30 October 1965 the first RF-4C Phantom IIs of the 16th Tactical Reconnaissance Squadron arrived at the base and on 16 November they began flying missions over Laos and North Vietnam.

[25][16]: 66–82 Unlike the USAF Farm Gate personnel at Bien Hoa Air Base, the C-47 co-pilots actually became part of the RVNAF operational structure – though still under U.S. control.

F-102s and TF-102s (two-seat trainer version) were deployed to Tan Son Nhut initially because ground radar sites frequently painted small aircraft penetrating South Vietnamese airspace.

[1]: 277  In May 1963 due to overcrowding at the base and the low-probability of air attack the T/F-102s and AD-5Qs were withdrawn to Clark AB from where they could redeploy to Tan Son Nhut on 12–24 hours' notice.

[3]: 113 In February 1973 the 3d Aerospace Rescue and Recovery Group left Tan Son Nhut AB and moved to Nakhon Phanom Royal Thai Navy Base.

The Unit was primarily responsible for controlling the tactical air resources of the US and its allies in South Vietnam, Thailand, and to some extent Cambodia and Laos.

The first tasks facing the USAF, however, were to set up a workable organizational structure in the region, improve the area's inadequate air bases, create an efficient airlift system, and develop equipment and techniques to support the ground battle.

The number of personnel at Tan Son Nhut AB increased from 7780 at the beginning of 1965 to over 15,000 by the end of the year, placing substantial demands for accommodation and basic infrastructure.

[1]: 246  In September 1962 Headquarters 6492nd Combat Cargo Group (Troop Carrier) and the 6493rd Aerial Port Squadron were organized and attached to the 315th Air Division, based at Tachikawa AB.

[1]: 246 On 10 August 1964 6 Royal Australian Air Force RAAF Transport Flight Vietnam DHC-4 Caribous arrived at the base and were assigned to the airlift system.

In addition to airlift of cargo and personnel and RVNAF training, it took on Ranch Hand defoliation and insecticide spraying; psychological/propaganda leaflet distribution; helicopter landing zone preparation; airfield survey; the operation of aerial ports; and other special missions.

In addition, the 377th ABW was responsible for housing numerous tenant organizations including Seventh Air Force, base defense, and liaison with the RVNAF.

An operating location of the wing headquarters was established at Bien Hoa AB on 14 April 1972 to provide turnaround service for F-4 Phantom IIs of other organizations, mostly based in Thailand.