新山一空軍基地

殖民时期

1920年法国殖民时期时建造了一个小型而未铺砌完整的飞行场，坐落于新山一以作为民航机场，因此名为新山一机场。在第二次世界大战爆发前，大多数航班都飞行往返法国的航线，也有至东南亚其他地方的航班。第二次世界大战期间，日本陆军用新山一机场作为一个运输基地。1945年8月日本投降之后，法国空军派遣了一支由150人组成的飞行支队接管新山一机场。
第二次世界大战后，新山一机场由国内线班机及进出西贡的国际航班使用。在1952年，法国空军第312特别任务中队从芽庄空军基地改驻到新山一，其下的C-47运输机和比奇18型机（Beechcraft Model 18s）从新山一出动，执行物资和军事人员运输任务以支援法军。

越南共和国（南越）空军使用情形

新山一空军基地于1953年起开始做为越南国军航空队（Vietnamese Armée de l'Air）的基地，1955年7月1日后南越成立了新的独立空军——越南共和国空军。尽管新山一基地在那之前已不时可见法军和越南军机，但直到1956年才将空军指挥部迁入该机场。
1960年代早期，随着南越空军规模的扩张，新山一空军基地派驻的航空器中也有愈来愈多是美军移交给南越的飞机，例如T-6教练机、A-1攻击机、O-1观测机和H-19直升机等。此外基地内的南越空军单位数量也有显著的增加，例如1964年1月4日在新山一编成的南越空军3311联队。这样的趋势一直发展到1960年代中期，当时新山一据称已经变成世界上最忙碌扰攘的机场。

军事地位

成为南越空军大本营的新山一空军基地，在初期主要仅作为指挥和行政设施使用，大部分的作战单位都部署在西贡东北方的边和空军基地。南越空军的人才招募中心也设在新山一。
新山一空军基地内设有南越空军在美国空军协助下创建的指挥管制系统，负责处理军机从各基地起飞、抵达任务区至返航降落的流程。这套被称为战术航空管制系统（TACS）的措施确保了空军能在各实施战斗行动的区域进行正确地管控，一旦缺乏，则可能使南越空军无法有效地依据需求派遣机队。TACS的设施紧邻在南越空军司令部及美国驻越空军指挥部旁边，方便两者利用。附属在TACS下的是设于南越各个军区的直接空中支援中心（DASC），负责支援各军区的陆上军事行动。第1中心（I DASC）在岘港空军基地、A中心（DASC Alpha）在芽庄空军基地、第2中心（II DASC）在波来古空军基地、第3中心（III DASC）在边和空军基地、第4中心（IV DASC）在芹苴的平水空军基地。
在各DASC中心下亦各自设有数个战术空中管制组（TACP），由一位以上的南越空军或美国空军人员组成，附编在特定的南越陆军部队之内。战术空管组－DASC中心－TACS系统构成的三级通信结构使新山一的空军总部可随时掌握战况。除此之外，还设有涵盖南越及周边部分地区的雷达系统，监控境内的任何攻击机。
由于新山一空军基地也是南越政府军的参谋总部所在地，因此在1960年代早期的频繁政变中数度成为冲突发生的地点。尤其在1963年倒琰政变中，政变军在11月1日下午邀请忠于总统吴廷琰的数位军官至参谋总部“参加午餐会”，然后以瓮中捉鳖之术关住所有人。当中最醒目的人物为支持琰总统的陆军特种部队指挥官黎光松上校和他的胞弟兼副指挥官——黎光绍少校。之后他们两人由政变发起者杨文明将军的护卫官——阮文戎上尉射杀，埋入空军基地旁的洞穴中。

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1968年春节攻势

新山一空军基地在1968年春节攻势中是越南共产党的主要目标. 袭击正在1月30号以比预期更猛烈的程度发生. 袭击发生在南越空军官兵准备回家过新年时.回岗命令立刻被发出，并且90%的南越空军在72小时内重新开始执勤。
第一轮对新山一空军基地袭击发生在一月30日晚约2：00。教堂是空军基地里最早的袭击目标。基地在空军上校法利皮布尔斯指挥下。
如果没有美国空军第377保安宪兵中队 和基地中美军四分之三骑兵的帮助,在袭击开始整个空军基地将会处于危险. 4名美军宪兵在Bunker 051上丧生; 他们和另外两位战斗保安宪兵因英勇行为获得银星勋章。保安宪兵尽管寡不敌众, 在 美国陆军直升机和地面部队帮助下, 击毙近100名敌军. 基地被美国和南越海空军戒备直到1968年1月31日中午12：00.
在接下来的3周中, 南越空军出动1300架次袭击，轰炸并扫射越共在南越的据点。从新山一空军基地出发的33D翼运输机在12日内起落15000次,相比平时每月仅10000次.侦察机也从新山一基地起飞约700架次, 并且南越飞行员也驾驶了O-1 Bird Dog和U-17 Skywagons.

战争越南化与1972年复活节攻势

In 1970, with American units leaving the country, the VNAF transport fleet was greatly increased at Tan Son Nhut. The VNAF 33d and 53d Tactical Wings were established flying Fairchild C-123 Providers, C-47s and De Havilland C-7A Caribous.
By November 1970, the South Vietnamese Air Force took total control of the Direct Air Support Center (DASCS) at Bien Hoa Air Base, Da Nang Air Base and Pleiku Air Base.
At the end of 1971, the VNAF were totally in control of command and control units at eight major air bases, supporting ARVN units for the expanded air-ground operations system. In September 1971, the USAF transferred two Fairchild C-119 squadrons to the VNAF at Tan Son Nhut.
In 1972, the buildup of the VNAF at Tan Son Nhut was expanded when two Lockheed C-130 Hercules squadrons were formed there. In December, the first VNAF C-130 training facility was established at Tan Son Nhut, enabling the South Vietnamese to train its own Hercules pilots. As more C-130s were transferred to the VNAF, older C-123s were returned to the USAF for disposal.
As the buildup of the VNAF continued, the success of the Vietnamization program was evident during the 1972 Spring Offensive. Responding to the communist attack, the VNAF flew more than 20,000 strike sorties which helped to stem the communist advance. In the first month of the offensive, transports from Tan Son Nhut ferried thousands of troops and delivered nearly 4,000 tons of supplies throughout the country.
The spring offensive also resulted in additional deliveries of aircraft to the VNAF under Project Enhance. New VNAF units came about with the introduction of Fairchild C-119K gunships at Tan Son Nhut, along with Boeing CH-47 helicopters, along with additional C-130 transports and numerous O-1 and O-2 observation aircraft.
Also, fighter aircraft arrived at Tan Son Nhut for the first time in the Northrup F-5A/B Freedom Fighter and the F-5E Tiger II. The F-5s were subsequently transferred to Bien Hoa and Da Nang Air Bases.

1973年巴黎和平协约后

The Paris Peace Accords of 1973 brought an end to the United States advisory capacity in South Vietnam. In its place, as part of the agreement, the Americans retained a Defense Attaché Office (DAO) at Tan Son Nhut Air Base, with small field offices at other facilities around the country. The technical assistance provided by the personnel of the DAOs and by civilian contractors was essential to the VNAF, 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.
It was through the DAO that the American/South Vietnamese relationship was maintained, and it was primarily from this source that information from within South Vietnam was obtained. The VNAF provided statistics with regards to the military capability of their units to the DAO, however the accuracy of this information was not always reliable.
From the Spring Offensive of 1972, it was clear that without United States aid, especially air support, the ARVN would not be able to defend itself against continuing communist attacks. 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.
The ARVN relied heavily on air support, and with the absence of the USAF, the full responsibility fell on the VNAF. Although equipped with large numbers of A-37 and F-5 attack aircraft, to conduct effective close air support operations, during the 1972 offensive the USAF relied on the heavier McDonnell Douglas F-4 Phantom II supporting ARVN forces dealing with those targets.
Numerous violations of the Paris Peace Accords were committed by communists beginning almost as soon as the United States withdrew its last personnel from South Vietnam by the end of March 1973. The North Vietnamese and the Provisional Revolutionary Government of South Vietnam continued their attempt to overthrow President Nguyễn Văn Thiệu and remove the U.S.-supported government. North Vietnamese military forces broke the treaty, and conquered  South Vietnam in their Ho Chi Minh Campaign. The U.S. had promised Thieu that it would use airpower to support his government. On January 14, 1975 Secretary of Defense James Schlesinger stated that the U.S. was not living up to its promise that it would retaliate in the event North Vietnam tried to overwhelm South Vietnam.
When North Vietnam invaded in March 1975, the promised American intervention never materialized. Congress reflected the popular mood, halting the bombing in Cambodia effective July 15, 1973, and reducing aid to South Vietnam. Since Thieu intended to fight the same kind of war he always had, with lavish use of firepower, the cuts in aid proved especially damaging.

新山一空军基地失守

1975年年初，北越人民军发起了1975年春季攻势，意在尽快地统一南越。在一系列进攻后，南越总统阮文绍就宣布放弃了越南中央高地和北方的两个省份。到了30月底时，岘港、归仁和芽庄都已经失守了，大规模的逃难潮开始南下，整个共和国陷入紊乱的局面。
As the war in South Vietnam entered its conclusion, the pilots of the VNAF flew sortie after sortie, supporting the retreating South Vietnamese Army after it abandoned Cam Ranh Bay on 14 April. For two days after the ARVN left the area, the Wing Commander at Phan Rang Air Base fought on with the forces under his command. 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.
The last of the 2d Air Division abandoned the airfield with the remaining flyable airplanes, leaving four A C-119s which had flown in from Da Nang and two A-37s to the North Vietnamese.
On 22 April Xuan Loc fell to the communists after a two-week battle with South Vietnam's 18th Army Division which inflicted over 5000 NVA casualties and delayed the Ho Chi Minh Campaign for two weeks. With the fall of Xuan Loc and the capture of Bien Hoa Air Base in late April 1975 it was clear that South Vietnam was about to fall to the North Vietnamese Army.
At dusk on 28 April, three captured A-37s, flown from the former VNAF Phan Rang Air Base bombed Tan Son Nhut destroying a number of aircraft on the flight line. There are conflicting stories about who was actually flying these aircraft. One source insists they were VNAF pilots who were communists, another says they were VNAF pilots who were forced to fly the mission in return for the safety of their families, and NVA General Van Tien Dung claimed the A-37s were flown by North Vietnamese Air Force pilots.
Whatever the case, the A-37s escaped. despite being pursued by several VNAF F-5s. Although the physical damage to Ton Son Nhut was not extensive, the threat of further air strikes eliminated Tan Son Nhut AB for fixed-wing evacuation flights, further lowering what little morale remained in the capital.
Saigon was now surrounded by thirteen NVA divisions and most Vietnamese realized it was only a matter of time until the entire country was in communist hands. On 29 April President Gerald Ford ordered Operation Frequent Wind, the helicopter evacuation of Saigon.
Vietnamese pilots now began flying themselves and their families out of the country in anything that could get off the ground. Some headed for the American rescue fleet just off the coast, while others flew to Thailand.
On 30 April the last desperate combat sorties flown by the VNAF were carried out in defense of Tan Son Nhut. An AC-119 Shadow gunship, which had spent the night defending the base perimeter, landed for fuel and ammunition. After refueling and rearming, the Shadow took off again. The gunship orbited the air base firing on advancing NVA troops and was soon joined by a pair of A-1s. The Skyraiders made repeated runs over NVA positions until NVA gunners downed one with a SA-7. The second A-1 pilot continued his attacks until his fuel and ordnance were used up. All the while, the AC-119 kept its fire directed on advancing enemy forces.
About 7:00 AM the Shadow was hit by an SA-7 and fell in flames. Three crewmen managed to bail out, but one chute became entangled in the debris and the airman killed.
In the final evacuation, over a hundred VNAF aircraft arrived in Thailand, including twenty-six F-5s, eight A-37s. eleven A-1s, six C-130s. thirteen C-47s, five C-7s, and three AC-119s. Additionally close to 100 VNAF helicopters landed on U.S. ships off the coast, although at least half were jettisoned. One O-1 managed to land on the USS Midway CV-41, carrying a South Vietnamese major, his wife, and five children. On 30 April 1975, Saigon fell and all remaining South Vietnamese forces were ordered to surrender.
For the VNAF thirty-five long years of war had come to an end. Following the war, Tan Son Nhut Air Base was taken over as a base for the Vietnam People's Air Force.

美军使用情形

During the Vietnam War (or Second Indochina War), Tan Son Nhut Air Base (then using the alternative spelling "Tân Sơn Nhứt") was an important facility for both the US Air Force and the VNAF. Tan Son Nhut Air Base served as the focal point for the initial United States Air Force deployment and buildup in South Vietnam in the early 1960s. After 1966, with the establishment of the 7th Air Force as the main USAF Command and Control Headquarters in South Vietnam, Tan Son Nhut functioned as a Headquarters base, a Tactical Reconnaissance base, and as a Special Operations base, focusing on areal defoliation (Operation Ranch Hand). With the drawdown of US forces in South Vietnam after 1971, the base took on a myriad of organizations transferred from deactivated bases in the country.
Between 1968 and 1974, Tan Son Nhut Airport was one of the busiest military airbases in the world.  During the last days of South Vietnam, Pan Am schedules from 1973 showed Boeing 747 service was being operated four times a week to San Francisco via Guam and Manila.  Continental Airlines operated up to 30 Boeing 707 military charters per week to and from Tan Son Nhut Airport during the 1968-74 period.
It was from Tan Son Nhut Air Base that the last U.S. Airman left South Vietnam in March, 1973.  The Air Force Post Office (APO) for Tan Son Nhut Air Base was APO San Francisco, 96307.

美军顾问团（MAAG）

In September 1961, the first permanent United States Air Force (USAF) unit, the 507th Tactical Control Group from Shaw Air Force Base South Carolina deployed sixty-seven officers and airmen to Tan Son Nhut to install radars and began monitoring air traffic and training of South Vietnamese Air Force (VNAF) personnel to operate and service the equipment. This organization formed the nucleus of what became a tactical air control system for a vast fleet of South Vietnamese and American aircraft.

战术侦察任务

During October 1961, four RF-101Cs and a photo processing unit from the 15th Tactical Reconnaissance Squadron of the 67th Tactical Reconnaissance Wing, based at Yokota AB Japan, arrived at Tan Son Nhut and joined the combat reporting post, with the reconnaissance craft flying photographic missions over South Vietnam and Laos within a few days of their arrival.
The RF-101C was the only Voodoo version to serve in Vietnam. The 67th TRW was soon followed by detachments of the 15th Tactical Reconnaissance Squadron of the 18th Tactical Fighter Wing, based at Kadena AB, Okinawa, which also flew RF-101 reconnaissance missions over Laos and South Vietnam, first from bases in Thailand and then from South Vietnam. These reconnaissance missions lasted from November 1961 through the spring of 1964.
RF-101Cs flew pathfinder missions for F-100s in the first USAF strike against North Vietnam on February 8, 1965. They initially operated out of South Vietnam, but later flew most of their missions over North Vietnam out of Takhli RTAFB, Thailand. 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 reconnaissance Voodoos at Ton Son Nuht were incorporated into the 460th Tactical Reconnaissance Wing in February 1966.  33 RF-101Cs were lost in combat in Southeast Asia—24 to Anti-aircraft artillery and small arms fire, 5 to Surface-to-air missiles, one to a MiG-21, one in a sapper attack on its base at Tan Son Nhut AB, and two to unknown causes. Six were lost in operational (non-combat related) accidents while serving in Southeast Asia. More than 30 RF-101Cs were lost in accidents during their early years of service, mainly due to pilot inexperience.
The last 45th TRS RF-101C left Tan Son Nhut on November 16, 1970, bringing the era of Voodoo participation in the Southeast Asia War to an end.

骡队计划（Mule Train）

During January 1962 a detachment of a dozen Fairchild C-123 Provider transports arrived in South Vietnam to provide tactical airlift support for South Vietnam's hard-pressed ground troops. Called "Mule Train", its primary purpose was to give the ground forces an assault capability via airdrop or insertion. Yet the unit also saw a great need for logistic support entailing daily delivery of supplies to remote sites in Vietnam.
On 13 November 1961, U.S. President John F. Kennedy approved a recommendation to increase the mobility of South Vietnam's hard-pressed military. The White House authorized the Air Force to deploy a squadron of Air Force C-123 Providers and 40 Army H-21 Shawnee helicopters to assist South Vietnam's forces.  On Dec. 6, the Defense Department ordered the 346th Troop Carrier Squadron (Assault) to the Far East for 120 days TDY "to participate in a classified training mission" in the official jargon of the day. A second Mule Train squadron, the 777th Troop Carrier Squadron (Assault), arrived in South Vietnam on June 15, 1962. Eventually, both squadrons were placed under the 315th Air Commando Wing.
Most sources fix Jan. 2, 1962, as the date that the initial group of aircraft arrived at Tan Son Nhut AB in South Vietnam.  All of the initial Mule Train missions were dedicated to carrying cargo. One-hundred-kilo sacks of rice were a major item, and at least one pilot over-grossed his aircraft by figuring them in at 100 pounds. The most typical commodities were live ducks, chickens, pigs, and cows, packed in locally made pens of wood and, when necessary, parachuted into the outlying camps. Mule Train aircraft also transported many Vietnamese natives. On more than one occasion, a Mule Train crew would smell smoke in the aircraft and find a traveler cooking food in the aircraft's cargo compartment.
There was no pretense that this was a South Vietnamese cargo operation, nor was there any training of Vietnamese for the task. Vietnamese were employed as "kickers" to move the cargo out the rear on re-supply drop.  The C-123 was a relatively simple and rugged aircraft. Its systems could take the heat and humidity of Vietnam better than more sophisticated aircraft. Tough landing gear and glider-strong fuselage could take the rough landings on short airfields, where stopping depended upon a slow approach, touching down on the edge of the airstrip, then full reverse and a steady, heavy foot on the anti-skid brakes.
Soon, the Mule Train route structure became linked to the hard-surface runways at Da Nang, Tan Son Nhut, Nha Trang, Bien Hoa, Pleiku, Ban Me Thuot, Huế, Da Lat, Sóc Trăng, Qui Nhơn, and Vũng Tàu. Virtually every Mule Train sortie began or ended at one of these airfields, but intermediate stops could be anywhere.
Two C-123 aircraft were maintained at Da Nang to support northern outposts.  The Mule Train crews were experienced in assault work, but they had to improvise for conditions in Vietnam. It was difficult to decide exactly where to drop paratroops over the rough terrain, and much depended upon the map-reading ability of the crew.
The die was cast on June 28, 1962, when 16 C-123s and 12 South Vietnamese C-47s dropped paratroops under adverse weather conditions about 35 miles north of Saigon. The operation went off well despite a 500-foot ceiling.
On other occasions, the C-123s would load up troops from the South Vietnamese airborne brigade in Saigon to fly to the relief of a village that had come under attack. Over the village, the C-123 pilot would reduce power, drop flaps, and spiral down to the drop altitude and give the paratroopers a green light to jump.
At times, C-123 crews were uncomfortable with the assault role. South Vietnamese Special Forces were sometimes capricious about when and where they would fight. Straight cargo operations were hazardous enough, especially during the monsoon season when South Vietnamese troops were socked in in the mountainous valleys. To execute the mission, the C-123s would line up in a proper direction, let down in the undercast, and if they did not break out by a given altitude, would climb back up. There were usually 800-foot ceilings in the valleys, and most of the time they broke out.
Mule Train missions during 1962 became extremely diverse, with the C-123s serving in roles ranging from duck delivery to napalm bombing. In the latter role, the Provider carried nine wooden pallets, each holding three 55-gallon drums of napalm mixed with gasoline. With a good kicker, the load could go out the back ramp in less than five seconds and leave a pattern of flame 1,200 feet long.
In October 1962, there began what became known as the Southeast Asia Airlift System. Requirements were forecast out to 25 days, and these requirements were matched against available resources. The 315th Troop Carrier Group and 8th Aerial Port Squadron came into being and set the stage for tighter control of airlift operations.  The era of the Mule Train operation was over. It left behind a record of success and a collection of procedures and techniques for cargo work in Southeast Asia.

The Dirty Thirty

Additional USAF personnel arrived at Tan Son Nhut in early 1962 after the VNAF transferred two dozen seasoned pilots from the 1st Transportation Group at Tan Son Nhut to provide aircrews for the newly activated 2nd Fighter Squadron then undergoing training at Bien Hoa Air Base. This sudden loss of qualified C-47 pilots brought the 1st Transportation Group's airlift capability dangerously low.
In order to alleviate the problem, United States Secretary of Defense Robert McNamara, on the recommendation of the Military Assistance Advisory Group (MAAG) Vietnam, ordered thirty USAF pilots temporarily assigned to the VNAF to serve as C-47 co-pilots. This influx of U.S. personnel quickly returned the 1st TG to full strength.
The Americans arrived at Tan Son Nhut during March and April 1962 and immediately began flying with Vietnamese crews. Unfortunately, problems arose between the Americans and Vietnamese and by August the situation had so deteriorated that the 1st Transportation Group commander. Nguyen Cao Ky urgently appealed for closer cooperation and understanding between the two groups. The situation seemed to gradually improve and although there were still problems, the two groups developed a closer working relationship.
Unlike the USAF Farm Gate personnel at Bien Hoa Air Base, the C-47 co-pilots actually became part of the VNAF operational structure - though still under U.S. control. Because of their rather unusual situation, these pilots soon adopted the very unofficial nickname, The Dirty Thirty.
In a sense they were the first U.S. airmen actually committed to combat in Vietnam, rather than being assigned as advisors or support personnel.
The original Dirty Thirty pilots eventually rotated home during early 1963 and were replaced by a second contingent of American pilots. This detachment remained with the VNAF until December 1963 when they were withdrawn from Vietnam.

第509战斗拦截中队

Starting in 1962, the 509th Fighter-Interceptor Squadron began rotating Convair F-102A Delta Dagger interceptors to Tan Son Nhut Air Base on a rotating basis to provide air defense of the Saigon area in the event of a North Vietnamese air attack.  These rotations from Clark ended in July 1970.
F-102's and TF-102's (two seat trainer version)were deployed to Tan Son Nhut initially because ground radar sites frequently painted small aircraft penetrating South Vietnamese airspace from the north. To determine if the unknown aircraft were infiltrators, drug smugglers or tourists, the F-102's were put on air defense alert, ready to scramble, intercept and identify the unknown, light aircraft that were crossing into South Vietnam.
The F-102, a supersonic, high altitude fighter interceptor designed to intercept Soviet bombers was given the mission of intercepting,identifying and, if necessary, destroying small aircraft, flying from tree top level to 2000 ft at speeds less than the final approach landing speed of the F-102.  The TF-102, employing two pilots with one acting solely as radar intercept operator, was considered to be safer and more efficient as a low altitude interceptor.
Before the rotation ended in July 1970, pilots and F-102 aircraft from other Far East squadrons were used in the deployment. 
F-102's were also deployed to DaNang on a temporary basis.

第33战术大队

On 8 July 1963 the MAAG units were organized as the 33d Tactical Group. The Group was equipped primarily with cargo aircraft, C-54 Skymasters, U-3Bs, VC-47, and VC-123z.
Its mission was to maintain and operate base support facilities at Tan Son Nhut, supporting the 2d Air Division and subordinate units by performing reconnaissance of Vietnam from various detachments flying RB-26 Invaders, RB-57 Canberras, and RF-101 Voodoo aircraft.
The early months of 1964 were a time of expansion, training, and comparative quiet. By midyear, the South Vietnamese Air Force had grown to thirteen squadrons; four fighter, four observation, three helicopter, and two C-47 transport. The South Vietnamese followed the practice of the U.S. Air Force, organizing the squadrons into wings, with one wing located in each of the four corps tactical zones at Cần Thơ Air Base, Tan Son Nhut Air Base, Pleiku Air Base, and Da Nang Air Base
After the Tonkin Gulf incident, the USAF response was to deploy twelve F-102 Delta Dagger air defense interceptor aircraft, their number divided between Tan Son Nhut and at Da Nang Air Base. In addition, eight F-100 Super Sabres joined the F-102s at Da Nang, and two squadrons of B-57 Canberra light bombers landed at Bien Hoa Air Base.

第6250战斗支援大队

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.
Starting with the buildup in 1965, the Air Force, while continuing to conduct the four air wars, adjusted its structure in Southeast Asia to absorb incoming units. Temporarily deployed squadrons became permanent in November. A wing structure replaced the groups. On 8 July 1965, the 33d Tactical Group was redesignated the 6250th Combat Support Group.

牧工行动

The 315th ACG was responsible for Operation Ranch Hand Defoliant operations missions. South Vietnamese president Ngo Dinh Diem requested USAF help to remove enemy cover. The USAF's Special Aerial Spray Flight was already using C-123s in the U.S. to control mosquitoes. After some modifications to the aircraft (which included adding armor for the crew), C-123B Provider aircraft arrived in Southeast Asia in January 1962 under the code name "Ranch Hand".
Flying specially-equipped C-123 Providers, members of the squadron flew low and slow to reduce the risks to our soldiers on the ground and to expose the enemy.  Ranch Hand never had more than five C-123Bs. Sometimes these aircraft had their spray equipment removed to conduct regular airlift flights, and it appeared that the defoliation mission might be eliminated altogether. With the increased U.S. commitment in South Vietnam in 1964 and 1965, however, requests for defoliation soared.
Ranch Hand grew into an essential part of the war effort, with over six million acres sprayed in South Vietnam between 1965 and 1969. Beginning in 1965 with only four aircraft, by the middle of 1969 Ranch Hand had about 25 UC-123 aircraft available for missions.  On 15 October 1966, Ranch Hand became the mission of the 12th Air Commando Squadron.
In 1965 Ranch Hand began using a very effective defoliant called Agent Orange, and the range of targets grew considerably.  The Agent Orange controversy later became both a political and veterans' issue. Operation Sherwood Forest sprayed the key Viet Cong-controlled Boi Loi Woods northwest of Saigon, and Operation Swamp Fox targeted the mangrove forests used by the communist for shelter in the Mekong Delta. Late in the year, operations extended into the Ho Chi Minh Trail in Laos. A flood of defoliation requests came in, and the small number of crews flew constantly.
The defoliation of vital enemy strongholds, transportation routes, and crops forced the communists to vigorously defend against the spraying. Ranch Hand aircraft regularly received damage on missions—considering their low altitude, low speed and large size, they were easy to hit. Ranch Hand maintainers worked constantly to repair the damage and get their UC-123s ready for the next mission. In addition to engines and flight controls shot out, and several crewmen wounded and killed, Ranch Hand lost five UC-123s in combat between 1966 and 1968.
In February 1967, Ranch Hand was ordered for the first time to fly missions over the De-Militarized Zone (DMZ) separating North and South Vietnam. These missions helped uncover infiltration routes from the north and expose stockpiles of supplies hidden in the DMZ. By June, 1967, the number of UC-123s had increased to 20.
During the Tet Offensive in early 1968, spraying operations were temporarily halted in favor of airlift missions. Between Feb. 5 and March 20, Ranch Hand UC-123s flew 2,866 airlift sorties.
The 315th ACW was transferred to Phan Rang Air Base on 14 June 1967.  With the Vietnamization drawdown in 1969, Ranch Hand was reduced from 25 to 13 aircraft. In 1970 Agent Orange was discontinued, and the existing stocks of Agent White ran out in May 1970. After the last anti-crop mission in January 1971, anti-mosquito spraying continued for a short time after, and then Ranch Hand ended.