The 504th Expeditionary Air Support Operations Group is an inactive
United States Air Force
The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...
unit. It was first activated as the 504th Tactical Air Support Group in 1966 for service during the
Vietnam War
The Vietnam War (1 November 1955 – 30 April 1975) was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam (Democratic Republic of Vietnam) and South Vietnam (Republic of Vietnam) and their allies. North Vietnam w ...
, and was reactivated in 2009 for service in Afghanistan. It was inactivated on 12 May 2016.
In Vietnam the group provided combat ready aircraft and crews in support of air and ground operations in Southeast Asia. It directed ground strikes, conducted visual reconnaissance and convoy escort. It also trained Air Liaison Officers and
Forward Air Controller
Forward air control is the provision of guidance to close air support (CAS) aircraft intended to ensure that their attack hits the intended target and does not injure friendly troops. This task is carried out by a forward air controller (FAC).
...
s. The
group
A group is a number of persons or things that are located, gathered, or classed together.
Groups of people
* Cultural group, a group whose members share the same cultural identity
* Ethnic group, a group whose members share the same ethnic iden ...
was thrice awarded the
Presidential Unit Citation for its actions during the war. It was inactivated in 1972 when the
Vietnamese Air Force
The Vietnam People's Air Force (VPAF; ), officially the Air Defence - Air Force Service (ADAF Service; ) or the Vietnam Air Force (), is the aerial, air and space defence service branch of Vietnam. It is the modern incarnation of the so-call ...
assumed its remaining mission.
On reactivation in 2009 it began to provide air support, air liaison, and weather support for ground operations until it was inactivated on 12 May 2016.
History
Vietnam War
Activation and initial training
The expansion of the U.S. presence in Southeast Asia and the use of airborne
forward air controller
Forward air control is the provision of guidance to close air support (CAS) aircraft intended to ensure that their attack hits the intended target and does not injure friendly troops. This task is carried out by a forward air controller (FAC).
...
s (FAC), rather than controllers on the ground, during 1965 and 1966 was accompanied by an increase from the single tactical air support squadron in theater at the beginning of 1965. In 1966, the new squadrons were assigned directly to the
505th Tactical Control Group, which also controlled the three radar squadrons in theater. By September 1966, they were attached to the Tactical Air Support Group, Provisional, 6253d. The 504th Tactical Air Support Group was organized at
Bien Hoa Air Base
Bien Hoa Air Base (Vietnamese language, Vietnamese: ''Sân bay Biên Hòa'') is a Vietnam People's Air Force (VPAF) military airfield located in South-Central southern Vietnam about from Ho Chi Minh City, across the Dong Nai river in the norther ...
, Vietnam in December 1966 to replace the 6253d as the headquarters for five tactical air support squadrons stationed throughout South Vietnam and in Thailand. In addition, two maintenance squadrons were transferred to provide for the group's fleet of
Cessna O-1 Bird Dog
The Cessna O-1 Bird Dog is a liaison and observation aircraft that first flew on December 14, 1949, and entered service in 1950 as the L-19 in the Korean War. It went to serve in many branches of the U.S. Armed Forces, was not retired until t ...
s. Each maintenance squadron provided a central location for two of the group's squadrons in the Republic of Vietnam.
[
However, the Air Force was unable to provide sufficient trained FACs to meet the demands of the war and the ]group
A group is a number of persons or things that are located, gathered, or classed together.
Groups of people
* Cultural group, a group whose members share the same cultural identity
* Ethnic group, a group whose members share the same ethnic iden ...
did not exceed 70% of its manning requirements in this area until 1969. Detachment 1 of the group was established at Binh Thuy Air Base
Binh Thuy Air Base (also known as Can Tho Air Base and Trà Nóc Air Base) was a United States Air Force (USAF), United States Navy, Republic of Vietnam Air Force (RVNAF) and Vietnam People's Air Force (VPAF) ''(Khong Quan Nhan Dan Viet Nam)'' ...
to operate the Theater Indoctrination School. In addition to preparing newly arrived pilots for their tours, the school also trained fighter pilots as FACs until 1968 in a program designed to help relieve the shortage of qualified FACS for operations.
More capable aircraft
In 1967, the group began to receive its first Cessna O-2 Skymaster
The Cessna O-2 Skymaster (nicknamed "Oscar Deuce") is a military version of the Cessna 337 Super Skymaster, used for forward air control (FAC) and psychological operations (PSYOPS) by the US military between 1967 and 2010.
Design and develop ...
s.[Rowley, p. 29] With two engines, the Skymaster was more capable than the Bird Dog, whose slow speed and lack of armor made it "fair game" for enemy gunners. Moreover, its limited power and navigational systems limited its use in mountainous areas and foul weather. The O-2 was conceived as an interim replacement for the O-1 until North American Rockwell OV-10 Bronco
The North American Rockwell OV-10 Bronco is an American twin-turboprop attack aircraft, light attack and surveillance aircraft, observation aircraft. It was developed in the 1960s as a special aircraft for Counter-insurgency aircraft, counter-ins ...
s became available. However, the demand for 504th FACs continued to grow and the O-2s augmented, rather than replaced the group's Bird Dogs. The 20th Attack Squadron at Da Nang Air Base
Da Nang Air Base () (1930s–1975) (also known as Da Nang Airfield, Tourane Airfield or Tourane Air Base) was a French Air Force and later Republic of Vietnam Air Force (RVNAF) facility located in the city of Da Nang, Vietnam. During the Vietnam ...
was the first of the group's units to fly the Skymaster.
Initially, O-2 pilots received only ground training before deploying to the theater, and the 504th conducted their flying training during theater indoctrination. However, the separation of ground and flying training for O-2 pilots proved to be problematical and, starting in March 1968, Tactical Air Command
Tactical Air Command (TAC) is an inactive United States Air Force organization. It was a List of Major Commands of the United States Air Force, Major Command of the United States Air Force, established on 21 March 1946 and headquartered at Lang ...
conducted both ground and flight training for them in Florida. After this program and the fighter pilot training program were discontinued, theater training was transferred to the group's operational squadrons and the school and Detachment 1 were discontinued in 1969.[
]
The final aircraft in the group's inventory, the OV-10 Bronco, began to arrive in 1968.[ Between July and October, a test and evaluation team, called Project Combat Bronco was attached to the 504th's ]19th Tactical Air Support Squadron
19 (nineteen) is the natural number following 18 and preceding 20. It is a prime number.
Mathematics
Nineteen is the eighth prime number.
Number theory
19 forms a twin prime with 17, a cousin prime with 23, and a sexy prime with 13. ...
at Phan Rang Air Base
Phan Rang Air Base (also called Thành Sơn Air Base) is a Vietnam People's Air Force (VPAF) ''(Khong Quan Nhan Dan Viet Nam)'' military airfield in Vietnam. It is located north-northwest of Phan Rang – Tháp Chàm in Ninh Thuận Provi ...
to evaluate the plane's combat capability. The group began accepting these planes as soon as the evaluation was completed. By 1971, the group was able to retire its last O-1s.[
]
Operations
Although controlling airstrikes was a large part of the FAC mission, group aircraft performed visual reconnaissance to detect enemy movements. South Vietnam was divided into sectors, with one or two FACs assigned to each. About 65% of the sectors were covered each day. Because Viet Cong
The Viet Cong (VC) was an epithet and umbrella term to refer to the communist-driven armed movement and united front organization in South Vietnam. It was formally organized as and led by the National Liberation Front of South Vietnam, and ...
forces typically moved during hours of darkness, most sorties were flown at dawn or dusk. The group's comprehensive visual reconnaissance program resulted in Viet Cong forces essentially halting daytime movement in areas visible from the air. The group also performed some limited photographic reconnaissance, using hand-held cameras It also performed bomb damage assessment
Bomb damage assessment (BDA), also known as battle damage assessment, is the practice of assessing damage inflicted on a target from a stand-off weapon, most typically a bomb or air launched missile. It is part of the larger discipline of combat ...
immediately following strikes its FACs controlled.[Rowley, p. 96]
As enemy rocket attacks on fixed bases became more frequent, the group began night operations near Saigon
Ho Chi Minh City (HCMC) ('','' TP.HCM; ), commonly known as Saigon (; ), is the most populous city in Vietnam with a population of around 14 million in 2025.
The city's geography is defined by rivers and canals, of which the largest is Saigo ...
and Da Nang
Da Nang or DanangSee also Danang Dragons (, ) is the fifth-largest city in Vietnam by municipal population. It lies on the coast of the Western Pacific Ocean of Vietnam at the mouth of the Hàn River, and is one of Vietnam's most important p ...
with O-1s and O-2s to "weed out" enemy rocket firing positions starting in February 1968. After June, the operation around Saigon expanded, with Army helicopter gunships assuming responsibility for two of the four sectors around the capital. Diversion of FAC aircraft to this mission was, however, at the expense of the daylight visual reconnaissance program.
Starting in the summer of 1969, some group OV-10s began to be armed, carrying out strikes while on visual reconnaissance missions. Although there was concern that arming FACs would divert them from their primary mission by "playing fighter pilot," strikes by FACs against fleeting targets substantially reduced the response time required to call fighters or gunships to the area. This program was concentrated in Vietnam, although it was expanded to include support for special forces
Special forces or special operations forces (SOF) are military units trained to conduct special operations. NATO has defined special operations as "military activities conducted by specially designated, organized, selected, trained and equip ...
teams operating in Cambodia and Laos.
When Army observers were not available, the unit performed artillery adjustment.[ The group provided also conducted convoy escort.][
]
Vietnamization
Vietnamization of FAC operations began in 1969, but proceeded slowly. In May 1971. US FACs ended operations in support of the Vietnamese Army and turned the mission over to the Vietnamese Air Force
The Vietnam People's Air Force (VPAF; ), officially the Air Defence - Air Force Service (ADAF Service; ) or the Vietnam Air Force (), is the aerial, air and space defence service branch of Vietnam. It is the modern incarnation of the so-call ...
(VNAF). By March 1972, VNAF controllers were directing 90% of airstrikes in South Vietnam. This permitted the 504th's 19th and 22nd Attack Squadron
: ''See 46th Bomb Squadron for the Strategic Air Command squadron''
The 22nd Attack Squadron is a United States Air Force unit assigned to the 432d Wing Air Combat Command at Creech Air Force Base near Indian Springs, Nevada. It flies General ...
s to transfer to bases in Hawaii and Korea by January 1972. On 15 March, the group was inactivated and its remaining squadrons were reassigned.[
]
Summary
During the Vietnam War, the group controlled personnel at over 70 different locations. Between 1967 and 1969, group pilots accounted for more than one third of all combat hours flown by Seventh Air Force
The Seventh Air Force (Air Forces Korea) (7 AF) is a Numbered Air Force of the United States Pacific Air Forces (PACAF). It is headquartered at Osan Air Base, South Korea.
The command's mission is to plan and direct air component operations in ...
. It flew 850,000 hours and supported 400 aircraft.
Afghanistan
The group was again activated in late March 2009 as the 504th Expeditionary Air Support Operations Group. From 2009 in Afghanistan the three squadrons of the group performed separate roles. Its 717th Expeditionary Air Support Operations Squadron coordinated with NATO
The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...
's International Security Assistance Force
The International Security Assistance Force (ISAF) was a multinational military mission in Afghanistan from 2001 to 2014. It was established by United Nations Security Council United Nations Security Council Resolution 1386, Resolution 1386 ac ...
and U.S. Forces-Afghanistan to provide air support throughout the region.[ The 817th Expeditionary Air Support Operations Squadron primarily embedded tactical air control parties with Army units.
The group's weather squadron created weather forecasts for the Army. Although headquartered at Bagram Air Base, the squadron maintained weather teams at 15 ]forward operating base
A forward operating base (FOB) is any secured forward operational level military position, commonly a military base, that is used to support strategic goals and tactical objectives. A FOB may contain an airbase, hospital, machine shop, and othe ...
s throughout Afghanistan. Often the sensors at these remote locations were "outside the wire", sometimes in locations more than 100 miles from the weather team.
As American involvement in Afghanistan was reduced, only the 817th Squadron remained of the group's units by the spring of 2016 and the group was inactivated and its remaining personnel and equipment transferred to the 817th.
Lineage
* Established as the 504th Tactical Air Support Group and activated on 5 December 1966 (not organized)
: Organized on 8 December 1966
: Inactivated on 15 March 1972
* Redesignated 504th Expeditionary Air Support Operations Group and converted to provisional status on 12 February 2009[
:: Activated c. 30 March 2009][
:: Inactivated on 12 May 2016
]
Assignments
* Pacific Air Forces
The Pacific Air Forces (PACAF) is a List of Major Commands of the United States Air Force, Major Command (MAJCOM) of the United States Air Force and is also the air component command of the United States Indo-Pacific Command (USINDOPACOM). PAC ...
, 5 December 1966 (not organized)
* Seventh Air Force
The Seventh Air Force (Air Forces Korea) (7 AF) is a Numbered Air Force of the United States Pacific Air Forces (PACAF). It is headquartered at Osan Air Base, South Korea.
The command's mission is to plan and direct air component operations in ...
, 8 December 1966 – 15 March 1972
* Air Combat Command
The Air Combat Command (ACC) is one of nine List of Major Commands of the United States Air Force, Major Commands (MAJCOMs) in the United States Air Force, reporting to Headquarters, United States Air Force (HAF) at the Pentagon. It is the prim ...
12 February 2009 to activate or inactivate as needed[
:: ]Ninth Air Force
The Ninth Air Force (Air Forces Central) is a Numbered Air Force of the United States Air Force headquartered at Shaw Air Force Base, South Carolina. It is the Air Force Service Component of United States Central Command (USCENTCOM), a joint D ...
c. 30 March 2009 – 12 May 2016
Components
* 19th Expeditionary Weather Squadron, unknown – 2014[Components were stationed with group headquarters, except as noted]
* 19th Tactical Air Support Squadron, 8 December 1966 – 15 January 1972[
:: Phan Rang Air Base, Vietnam
* 20th Tactical Air Support Squadron, 8 December 1966 – 15 March 1972][
:: Da Nang Air Base, Vietnam
* , 8 December 1966 – 15 March 1972][
:: ]Pleiku Air Base
Pleiku Air Base is a former air force base in Vietnam. It was established by the Republic of Vietnam Air Force (RVNAF) in 1962 at an undeveloped airstrip, and was used by the United States Air Force during the Vietnam War in the II Corps (Sout ...
, Vietnam after September 1971, Tan Son Nhut Air Base, Vietnam after January 1972
* 22d Tactical Air Support Squadron, 8 December 1966 – 15 May 1971[
:: Binh Thuy Air Base until January 1970, Bien Hoa Air Base, Vietnam
* ]23rd Flying Training Squadron
The 23rd Flying Training Squadron is a unit of the United States Air Force, currently assigned to 58th Operations Group performing helicopter training at Fort Novosel, Alabama.
Mission
Since January 1994, the 23d Flying Training Squadron is t ...
, 8 December 1966 – 15 March 1972[
:: ]Nakhon Phanom Royal Thai Air Force Base
The Nakhon Phanom Royal Thai Navy Base (NKP), formerly Nakhon Phanom Royal Thai Air Force Base, is a Royal Thai Navy facility used for riverine patrols along the Mekong River. It is approximately northeast of Bangkok, west of Nakhon Phanom ...
, Thailand
* 505th Tactical Control Maintenance Squadron, 8 December 1966[Rowley, p. 50] – 15 March 1972
:: Tan Son Nhut Air Base
Tan Son Nhut Air Base () (1955–1975) was a Republic of Vietnam Air Force (RVNAF) facility. It was located near the city of Saigon in southern Vietnam. The United States used it as a major base during the Vietnam War (1959–1975), stationing ...
, Vietnam[
* 506th Tactical Control Maintenance Squadron, 8 December 1966][ – 15 March 1972
:: ]Udorn Royal Thai Air Force Base
Udorn Royal Thai Air Force Base (Udorn RTAFB) is a Royal Thai Air Force (RTAF) base, the home of 23rd Wing Air Command. It is in the city of Udon Thani in northeastern Thailand and is the main airport serving the city and province.
The RTAF 23 ...
, Thailand[
* 717th Expeditionary Air Support Operations Squadron, c. 30 March 2009][ – 12 May 2015
:: ]Kabul International Airport
Kabul International Airport () is located in the northern part of Kabul, Afghanistan.
It is one of the country's main international airports, capable of housing over a hundred military and civilian aircraft. It is currently operated by UAE-base ...
, Afghanistan[
* 817th Expeditionary Air Support Operations Squadron, c. 30 March 2009][ – 12 May 2016
* 917th Expeditionary Weather Squadron, c. 30 March 2009][ – unknown
]
Stations
* Bien Hoa Air Base, Vietnam, 8 December 1966
* Cam Ranh Bay Air Base, Vietnam, 30 April 1970
* Phan Rang Air Base, Vietnam, 1 October 1971 – 15 January 1972[
* Bagram Air Base, Afghanistan, c. 30 March 2009 – 30 March 2010
* Kabul International Airport, Afghanistan, 1 April 2010 – 12 May 2016
]
Aircraft
* Cessna O-1 Bird Dog, 1966–1971
* Cessna O-2 Skymaster, 1967–1972
* North American Rockwell OV-10 Bronco, 1968–1972[
]
Awards and campaigns
References
; Notes
; Citations
Bibliography
*
*
External links
*
*
*
* (YouTube Video version)
455 AEW's Bagram Airfield Official Site
{{USAF Air Support Operations
Air Support Operations 0504
Military units and formations of the United States Air Force in the Vietnam War