U-Tapao Royal Thai Navy Airfield

Military airport in Rayong, Thailand
the civilian use of this facility

U Tapao Royal Thai Navy Airfield is a military airfield of the Royal Thai Navy (RTN) approximately southeast of Bangkok in the Ban Chang District of Rayong Province near Sattahip on the Gulf of Thailand. It is serves as the home of the RTN First Air Wing.

U Tapao (อู่ตะเภา) is a compound of อู่ cradle or drydock and ตะเภา trade winds, and derives from the site having once been a shipyard for construction of ruea tapao (เรือตะเภา), a type of argosy resembling a Qing Dynasty junk.

In 1965 the RTN was permitted by the Council of Ministers to build a 1,200 meter long airfield near U Tapao village, Ban Chang District, in Rayong Province. The US, seeking a Southeast Asian B 52 base, reached an agreement with the Thai government to build and operate the base in conjunction with the Royal Thai Navy. The US began construction of the runway and all facilities on 15 October 1965 and completed it on 2 June 1966. The base was administratively handed over to the RTN on 10 August 1966. The 11,000 feet (3353 m) runway became operational on 6 July 1966 and U Tapao received its first complement of United States Air Force (USAF) Strategic Air Command (SAC) KC 135 tankers in August 1966. The USAF had been flying B 52 Operation Arc Light bombing missions from Kadena Air Base on Okinawa, but Okinawa was judged to be too far from Vietnam to meet mission requirements. An optimal solution was to base the B 52s in South Vietnam or Thailand, however base security in South Vietnam was problematic. U Tapao had an existing runway suitable for the bombers and the cost for upgrades to the base was minimal. In January 1967, negotiations between the US and Thai government started to base them at U Tapao. The agreement, reached on 2 March 1967, allowed 15 B 52s and their support personnel to be based at U Tapao, with the provision that missions flown from Thailand would not over fly Laos or Cambodia on their way to targets in Vietnam. The first B 52's arrived on 10 April 1967. The next day, B 52 sorties were flown from U Tapao. By 1972 there were 54 B 52 aircraft stationed in Thailand.

Prior to 1965, the base at U Tapao was a small RTN airfield. At Don Muang Air Base near Bangkok, the USAF had stationed KC 135 tanker aircraft to refuel combat aircraft over the skies of Indochina. Although Thailand was an active participant in the Vietnam War, with a token ground force deployed to the South Vietnam as well as involved in the largely secret civil war in Laos, the presence and the visibility of USAF aircraft near its capital city was causing a fair degree of political embarrassment for Thailand's military government. In June 1965, the B 52 was first used in the Vietnam War. B 52 aircraft from the 7th and 320th Bomb Wings were sent to bomb suspected Viet Cong enclaves in South Vietnam, the operation being supported by KC 135As stationed at Kadena AB on Okinawa. In September 1966 2 radio relay KC 135A Combat Lightning aircraft and their personnel were ordered to deploy to U Tapao to support air operations over North Vietnam. The expansion of U Tapao RTN airfield began in October 1965. The runway was built in eight months and the base was completed slightly more than two years later. The 11500 feet (3505 m) runway was opened on 6 July 1966 and the first aircraft to land was a Royal Thai Air Force HH 16 helicopter, then a USAF C 130 Hercules cargo aircraft. With the completion of U Tapao, most US forces were transferred from Don Muang, and U Tapao RTNAF became a front line facility of the United States Air Force in Thailand from 1966 to 1975. The USAF forces at U Tapao were under the command of the United States Pacific Air Forces (PACAF), with the Strategic Air Command (SAC) units being a tenant unit. The APO for U Tapao was APO San Francisco, 96330

The 4258th Strategic Wing (SAC) was activated in June 1966 at U Tapao under the 3rd Air Division, Andersen AFB, Guam. The wing was charged with the responsibility of supporting refueling requirements of USAF fighter aircraft in Southeast Asia, plus conducting bombing missions on a daily basis. Steadily progressing and adding to the mission, U Tapao welcomed its first complement of KC 135 tankers in August 1966. By September, the base was supporting 15 tankers. From 1966 to 1970, 4258th wing tankers flew over 50,000 sorties from U Tapao. The Seventh Air Force (PACAF) wanted additional B 52s missions flown in the war zone. B 52 missions from Andersen and Kadena, however, required long mission times and aerial refuelling en route. Having the aircraft based in South Vietnam made them vulnerable to attack. It was decided that, as the base at U Tapao was being established as a KC 135 tanker base, to move them all out of Don Muang and to also base B 52s at U Tapao where they could fly without refuelling over both North and South Vietnam. In March 1967, the Thai Government approved the stationing of B 52s at U Tapao; on 10 April 1967, three B 52 bombers landed at U Tapao following a bombing mission over Vietnam. The next day, B 52 operations were initiated at U Tapao and by 15 July, B 52s were typically operating from U Tapao. Under Operation Arc Light, wing bombers flew over 35,000 strikes over South Vietnam from 1967 to 1970. lost power in the outside right engine (#4) on takeoff at U Tapao and crashed, killing all four crew members.

On 10 January 1972, three communist sappers attempted to destroy B 52s in a sapper attack using grenades and satchel charges. One attacker was apparently killed in the attack, while the other two managed to cause minor damage to three B 52s before fleeing the base.

In late March 1972, the North Vietnamese launched a full scale offensive across the Vietnamese Demilitarized Zone, supported by tanks and heavy artillery. By this time, the US was no longer in the forefront of the ground war, with South Vietnamese units taking the lead. However, the US was still providing air power, and President Richard Nixon ordered a large increase on US airpower in response to the invasion. Although there had been no campaign of strikes into North Vietnam since the end of Rolling Thunder, the Nixon Administration ordered a new air offensive, initially code named Freedom Train, later becoming Operation Linebacker, with relatively few restrictions on targets that could be hit. At this time 51 B 52s were based at U Tapao.

In late 1972 the Nixon Administration ordered an all out air offensive against North Vietnam. The bombing raids, codenamed Operation Linebacker II, began on 18 December 1972 involving heavy attacks by almost every strike aircraft the US had in theater, with the B 52 playing a prominent role. The initial plan scheduled attacks for three days. Along with heavy strikes by USAF and Navy tactical aircraft, 129 B 52s in three waves (approximately four hours apart) from the 307th Strategic Wing at U Tapao RTNAF and B 52Ds and B−52Gs of the 43d Strategic Wing and the 72 Strategic Wing (Provisional) both at Andersen AFB. The U Tapao based B 52Ds were able to carry more bombs and perform more sorties than the other units which operated less capable versions and had to fly much further to reach targets in North Vietnam. On 13 April, the Eagle Pull evacuees were flown to U Tapao on HMH 462 helicopters. After their arrival, the Vietnamese were sequestered in tents near the runway. The adjacent parking ramps and grassy areas were being filled to capacity with South Vietnamese helicopters and aircraft. VC 47A 084 of Air America crashed on landing on a flight from Tan Son Nhut. On 30 April the South Vietnamese government surrendered. The handful of RVNAF planes that had been performing last ditch air strikes completed their missions and flew to U Tapao. The former RVNAF C 130s that had arrived in Thailand were flown out to Singapore, while 27 RVNAF A 37s, 25 F 5s, and 50 UH 1s at U Tapao were loaded by helicopter and barge onto Midway for transport to the US.

On 12 May 1975, less than two weeks after the fall of Saigon, a unit of the Cambodian Khmer Rouge Navy seized the American flagged container ship SS Mayaguez, taking the crew hostage. A U Tapao based US Navy P 3 Orion was one of the first aircraft sent to locate the Mayaguez. On 13 May, Seventh Air Force commander Lieutenant General John J. Burns and his staff developed a contingency plan for volunteers of the Nakhon Phanom Royal Thai Air Force Base 56th Security Police (SP) Squadron to be dropped onto the containers on the decks of the Mayaguez. The next morning, 75 SPs from the 56th boarded helicopters of 21st Special Operations Squadron to proceed to U Tapao for staging. A CH 53 #68 10933 crashed, killing 18 SPs and the five man flight crew. The hasty attempt to effect recovery of the vessel and her crew using only USAF resources was abandoned. U Tapao then served as a staging point for U. S. Marines to deploy aboard the remaining CH 53s of the 21st SOS and HH 53s of the 40th Aerospace Rescue and Recovery Squadron and assault Koh Tang Island some 195 nautical miles from U Tapao, where the Mayaguez crew was believed to be held. the political climate between Washington and the government of PM Sanya soured. Immediately after the news broke of the use of Thai bases to support the Mayaguez rescue, the Thai government lodged a formal protest with the US and riots broke out outside the US Embassy in Bangkok. The 3rd Aerospace Rescue and Recovery Group left on 31 January 1976,

For several years, beginning in 1981, U Tapao has hosted parts of Cobra Gold, jointly involving US, Singaporean, and Thai armed forces, and designed to build ties between the nations and promote interoperability between their military components. Thailand is an important element in The Pentagon's strategy of "forward positioning". Despite Thailand's neutrality on the 2003 invasion of Iraq, the Thai government allowed U Tapao to be used by American warplanes flying into combat in Iraq, as it had earlier done during the war in Afghanistan. In addition, U Tapao may be where Al Qaeda operative Abu Zubaydah was interrogated, according to some retired American intelligence officials. A multinational force headquarters was established at U Tapao to coordinate humanitarian aid for the Sumatran tsunami of 26 December 2004. On 7 May 2008, in the aftermath of Cyclone Nargis, Thai C 130 transports were permitted to land at Yangon International Airport in Burma, carrying drinking water and construction material. From 12 to 20 May, USAID and the U. S. Department of Defense (DOD) coordinated the delivery of nearly US$1.2 million of relief commodities to Yangon on 36 DOD C 130 flights, with supplies sufficient to provide assistance to more than 113,000 beneficiaries. The DOD efforts were under the direction of Joint Task Force Caring Response. As of 26 June 2008, United States assistance directed by the USAID DART (Disaster Assistance Response Team) stationed in Thailand, had totaled US$41,169,769. Units involved were the 36th Airlift Squadron (36 AS) of the 374th Airlift Wing (374 AW) from Yokota Air Base, Japan, flying C 130H Hercules; and Marine Aerial Refueler Transport Squadron 152 (VMGR 152) from Marine Corps Air Station Futenma, Okinawa, Japan, flying the Lockheed Martin KC 130R and the newer KC 130J. In 2012, a proposal for the United States National Aeronautics and Space Administration (NASA) to use U Tapao to support weather research was rejected by the Thai government. In 2015, a Politico article reported that the United States Government rented space at U Tapao from a private contractor for use as a "major logistics hub for the Iraq and Afghanistan wars." Because the lease was technically with a private contractor, this allowed "U. S. and Thai officials to insist there's no U. S. 'base' and no inter governmental basing agreement."