20th Tactical Air Support Squadron

submitted by: Alva Leon Matheson

On 8 May 1965, at DaNang AB, Republic of Vietnam, the 20th Tactical Air Support Squadron (TASS) was organized and entered the USAF inventory. The 20th TASS along with other newly formed TASS units were authorized a complement of more than thirty O-1 aircraft to perform its mission. This allocation proved difficult to fill, since the aircraft were being transferred from other agencies, primarily the Army. Four months before its organization, the Air Force had 20 aircraft required by the TASSs in Vietnam. The TASS’s growth was dependent on and linked to the acquisition of the O-1s from other agencies. While TASS operations were initiated in August 1965, it wasn’t until the end of the year that the 20th TASS received its full complement of aircraft.
As the Forward Air Controller (FAC) pilots began to arrive, they were provided with familiarization checkouts and theater indoctrination flights. Upon completion of these requirements, FACs were assigned to support US and Vietnamese Army units. During this period, FACs were given many and varied tactical call signs.
In the latter part of 1965, the 20th TASS was assigned the out-of-country mission, which entailed flying interdiction missions over the Ho Chi Minh trail in Laos. Its area of operations (AO) was designated TIGERHOUND. To meet its mission requirements it was necessary to establish a number of forward operating bases (FOB) to support the operation. Initially, FOBs were established at Khe Sanh, Kham Duc, and Kontum. Eventually, the sites were expanded to include DaNang, Dong Ha, Dak To, and Pleiku
In mid-July 1966, the 20th TASS was assigned another mission and AO. The new mission was designed TALLY HO. The AO was part of the STEEL TIGER area located in North Vietnam from the Demilitarized Zone (DMZ) to about 30 miles north of the DMZ. The TALLY HO missions were flown from Dong Ha. During this period, it was decided that all out-of-country tactical call signs would carry the name of COVEY.
The O-1, whether by design or accident proved to be an outstanding FAC aircraft. It provided exceptional visibility, was not complicated, and was surprisingly easy to fly. However, as the weapons of the Viet Cong and the North Vietnamese regulars became more sophisticated, the O-1’s vulnerability was accentuated. This vulnerability was countered by a new FAC aircraft.
The new FAC aircraft was the Cessna O-2A, which was a modified Cessna 337. It was an inline dual engine aircraft with one propeller pushing and the other pulling. From late 1966 until late 1968, approximately 350 O-2s were contracted for by the Air Force. The first O-2s to arrive in country were assigned to the 20th TASS. They were then assigned to Dong Ha and Khe Sanh to provide a more substantial FAC aircraft to deal with the improvements in the enemy’s weaponry. By reading some of the narratives submitted by O-2 pilots, the reader will become acutely aware of the O-2’s capabilities and limitations.
The O-2 was an interim aircraft, but it filled a void while the OV-10 was being developed. The OV-10 was a more sophisticated and durable FAC vehicle: it had greater ordinance carrying capability, more loiter time, a bit more power, and a greater array of conventional navigation aids and in-flight instrumentation. The 20th TASS received its first OV-10s in July 1969. The arrival of the OV-10s to complement the O-2As resulted in the transfer of the O-1s to other units.
By October 1969, the 20th TASS, while supporting five US Army and six South Vietnam force locations, as well as the out-of-country operations, was operating from Danang and eleven FOBs. As the US Army began to gradually reduce its presence in 1972 and 1973, the 20th TASS began withdrawing from its FOBs.
In response to the North Vietnamese spring offensive of 1972, the 20th TASS reestablished some of its former FOBs. It is notable to mention that in June 1972, the 20th TASS had tripled its pre-invasion sorties. Further, Covey FACs from DaNang using OV-10s were a vital and integral part of base defense operations during that year.
In January 1973, the 20th TASS ceased operations at its last FOB, and flew its final missions in Vietnam. The O-2s were turned over to the Vietnamese Air Force, and the OV-10s were assigned to other USAF units in Southeast Asia.
On January 25, 1973, the 20th TASS moved, without personnel or equipment, to George AFB, California.