The Royal Australian Navy (RAN) did not confine its effort in Vietnam to seaborne activity; the Fleet Air Arm provided an additional Australian aerial presence during the war.
In December 1966, the United States Government requested Australian assistance to meet the need for additional air crew and maintenance personnel. Australia, recognising the heavy toll that the war was taking on US air crew, offered a detachment of RAN airmen and support personnel. Named the Royal Australian Navy Helicopter Flight Vietnam (RANHFV), the Vietnam-bound naval personnel had to replace training in anti-submarine warfare with new skills. Now they learnt how to drop troops into, or extract them from, dangerous landing zones as well as methods of escape and evasion if they were shot down – an increasingly common occurrence for helicopter crews on combat operations in Vietnam.
The first RANHFV contingent reached Vietnam on 16 October 1967. The Flight, having to integrate with the United States 135th Assault Helicopter Company, was designated an Experimental Military Unit and became known by the acronym EMU. Initially based at Vung Tau, the 135th Assault Helicopter Company flew Iroquois and provided the tactical movement of combat troops, supplies and equipment in what, during the Vietnam War, were known as air-mobile operations.
Two months after their arrival in Vietnam, the 135th, including the RANHFV, moved from Vung Tau to the American base at Black Horse in Long Khanh province, thirty-five miles away. Amidst rubber plantations and jungle, Black Horse was far more vulnerable to enemy attack than Vung Tau. The facilities too were more primitive and the ever-present dust made helicopter maintenance more difficult. During the Tet offensive conditions at Black Horse became more precarious, fighting on the camp's boundaries became more frequent and enemy mines made the supply route to the camp increasingly dangerous.
Even after the fighting associated with Tet subsided helicopter crews continued to fly daily missions and combat assaults that left crews and maintenance personnel exhausted. For aircrew, the routine meant rising at 4.30 in the morning, eating breakfast and collecting combat rations before beginning the day's flying which, not infrequently, would end 12 or more hours later.
In November 1968 the 135th, including the RANHFV was reassigned and moved to Camp Martin Cox at Bear Cat, a large base in Bien Hoa province that, housed the Royal Thai Army volunteer force and United States aviation units. During the third RANHFV contingent's tour the 135th moved again, this time to Dong Tam, south of Saigon in South Vietnam's Mekhong Delta region. Once more RANHFV personnel found themselves having to develop facilities to make the base more habitable while continuing to fly a full schedule of operations.
Each of the four RANHFV contingents lived and fought under similar conditions. Routine flying, still exhausting and dangerous, was interspersed with periods of intense combat. Over the course of a year-long tour a contingent's flight crews commonly logged a combined total of between 9,000 and 12,000 flying hours.
The RANHFV ceased operations on 8 June 1971, the 135th and the Australians were giving way to the process of disengagement and 'Vietnamisation' - devolving responsibility for operations to South Vietnamese forces. Shortly afterwards the 135th moved to Dien, northeast of Saigon. By the time the RANHFV left Vietnam, more than 200 personnel had served in the four contingents. The unit flew hundreds of offensive operations, placing great strain on both men and machines, and was involved in some of the most intense combat experienced by Australians in the war. Five members of the Flight lost their lives in Vietnam, some 22 were wounded in action. Their having served in a combined US/Australian formation was a source of pride for personnel of both countries.