In 1965, the U.S. Marine Corps established a base across Highway 1 from the 3rd RRU facility. In late 1965, The 3rd Marine Division established its headquarters at Phu Bai and would remain there until late 1967, when it was moved forward to Đông Hà. In late November 1967, the base was named Camp Hochmuth in honor of Bruno Hochmuth, Commanding General, 3rd Marine Division, who was killed in a helicopter explosion north of Huế. In June or July 1968, U.S. Special Forces established Forward Operating Base 1 at Phu Bai. The base remained in use until early 1969. Marine units based at Phu Bai during this period included:
On 30/31 January 1968, the base was hit by Vietcong mortar and rocket fire as part of the Tet Offensive. The base was used to support U.S. and ARVN forces fighting in the Battle of Huế. The first relief force was dispatched from Phu Bai to the MACV Compound in Huế City. On 15 February 1968, General Creighton Abrams established MACV forward at Phu Bai to assume direct control of US forces in northern I Corps, which were then engaged in the Battle of Huế, the Battle of Khe Sanh, and the Tet Counteroffensive. On 10 March 1968, MACV Forward, having served its purpose, was converted to a Corps headquarters and designated Provisional Corps, Vietnam, under the command of Lieutenant General William B. Rosson. Rosson exercised operational control over the 3rd Marine Division, the 1st Cavalry Division, the 101st Airborne Division and assigned Corps troops. The new Corps also co-operated closely with the ARVN 1st Division in the area. Provisional Corps, Vietnam, was designated XXIV Corps on 12 August 1968. The 45th Engineer Group moved north to the Phu Bai area in February 1968, where it assumed general construction support missions for the I Corps Tactical Zone. The group then remained in the Da Nang area until departing Vietnam.
1969–72
In 1969, the 85th Evacuation Hospital moved from Qui Nhơn and was established at the northwest end of the airfield, adjacent to Highway 1. In 1969, the headquarters of the 101st Airborne Division was moved to Phu Bai. Units based at Phu Bai during this period included:
220th Aviation Company
HMM-161
1973-5
The ARVN operated Phu Bai as a forward logistics base, and it was the only airport serving Huế. In September 1974, during the Battle of Phú Lộc, after pushing the ARVN defenders off Mo Tau Mountain, the People's Army of Vietnam targeted artillery fire against the base until they were evicted by the ARVN 1st Division and 15th Ranger Group on 11 December.
1975
From 5 March 1975, the PAVN shelled the base as part of the Hue–Da Nang Campaign. Nonetheless, the base continued to be used for aerial reinforcement of the ARVN, until it was overrun by the PAVN on 23/24 March 1975.
Gustav Hasford wrote about his experiences in and around Phu Bai in 1968, in his semi-autobiographical novels The Short-Timers and The Phantom Blooper.
In the film Full Metal Jacket, based mainly on The Short-Timers and in part on The Phantom Blooper, two combat journalists for Stars and Stripes, Joker and Rafterman, are sent to Phu Bai, where they cover as well as participate in the action there, and in Hue, in January 1968.
