Throughout much of the Second Indochina War the Thai airforce bases at U-Tapao and Nakhon Phanom performed as major strategic points for the United States military in its air war against North Vietnam and its unofficial air war against Laos.
Even after the ceasefire of January 1973 and subsequent withdrawal of US combat forces from South Vietnam, U-Tapao and Nakhon Phanom served as bases of operations for the Americans. Equally, the air bases in Udon Thani and Khorat also played important roles.
In January 1974, President Thieu of South Vietnam announced that war had once again started with the North. A year later and it became increasingly clear the North Vietnamese and their Viet Cong allies were likely to achieve the full conquest of South Vietnam.
As the North Vietnamese invasion gathered momentum and the area held by the Thieu government became smaller and centred on the capital of Saigon, the US government prepared for the inevitable.
In nearby Cambodia, the Khmer Rouge were closing in on the capital Phnom Penh, and it was equally obvious this city would soon fall.
With US citizens, government officials, and military personnel still in both countries, preparations were made to utilize the services of those US air assets on the ground in Thailand as well as the aircraft carriers of the US Seventh Fleet.
Operation Eagle Pull, the evacuation of US Ambassador John Gunther Dean and Cambodian President Saukhm Khoy, and other foreign nationals, from Phnom Penh and launched on 15 April 1975 went off without a problem.
Included among the US forces for that Cambodian operation was a Special Operations Squadron (SOS) based at Nakhon Phanom. It, along with an air rescue squadron at the same location were the two primary helicopter squadrons for remaining operations in Southeast Asia following the American withdrawal from South Vietnam, Laos and Cambodia.
Almost as soon as the Phnom Penh operation was completed, eight helicopters from the squadron along with two from the rescue squadron were sent to U-Tapao airbase.
Arriving on 18 April, the air crews were given a briefing about shipboard operations by two naval aviators flown in for that purpose. The helicopters were to be flown at night to a rendezvous point with the carrier USS Midway.
The Americans took off in the middle of the night from U Tapao, flew along the Cambodian coastline and then via the tip of southern Vietnam, keeping out of radar range.
After meeting up with a US Navy aircraft that gave them the co-ordinates for the Midway, the helicopters headed out to sea to try and locate the carrier task force. At this point the Midway was operating under a total electronic emissions blackout and had no lights switch on. As one of the pilots noted, “We were real short on fuel when we found them.” The flight had taken five hours.
As the North Vietnamese encircled and closed in on Saigon, the US ambassador to South Vietnam, Graham Martin, delayed the evacuation for as long as possible, but finally issued the necessary instructions to commence the withdrawal. Martin was later heavily criticised for his long delay in issuing the evacuation order.
Operation Frequent Wind, as the evacuation was code-named, was instituted on 29 April.
With Tan Son Nhut airport under attack it was impossible for fixed-wing aircraft to be deployed, so the task fell to US naval and Marine Corps helicopters instead.
The operation began at 2.30pm and for the next 14 hours, until 4.30am on 30 April, the air crews worked non-stop.
To help with close security, the US Air Force had a number of gunships from Khorat to supply close support and the co-ordination of the operation came via an Airborne Command and Control Squadron flying out of Udon.
As the official US naval history reports, ‘With fighter cover provided by carrier aircraft, the helicopters landed on Saigon rooftops and at Tan Son Nhut to evacuate the Americans. The airport became the main helicopter landing zone; it was defended by Marines from the 9th Amphibious Brigade flown in for that purpose. All but a handful of the 900 Americans in Saigon were evacuated. The last helicopter lifted off the roof of the United States Embassy at 7:52 PM carrying Marine security guards.’
The numbers evacuated look impressive. In total, 7,806 US citizens and foreign nationals were brought out of Saigon in a series of more than 600 sorties into the US embassy compound and the US Defense Attaché compound (which was adjacent to Tan Son Nhut airport). Many of these landings and take-offs took place under fire.
Two Marine Corps security guards were killed when an artillery shell burst close to them. Two helicopter crewmen were presumed dead following a crash at sea as they flew towards the aircraft carrier USS Hancock. Apart from these four men, no other casualties were sustained.
Sadly, two weeks later, the Mayaguez incident would prove to be far more costly in terms of lives lost. Yet again the Thai airforce bases would prove invaluable assets for the Americans.