TCS and the TASS units were under Operational Control of the relevant DASC.

Mission. The mission of the TCS was to operate and maintain the tactical control radar elements of the TACS as part of the implementation of the Southeast Asia Integrated Tactical Control System (SEAITACS).

These squadrons with detachments were responsible for the following functions:

• Air Defense
• Tactical Flight Following
• Fighter Tanker Rendezvous
• Fighter Recovery
• Routine Flight Recoveries
• Radar Advisories
• Artillery Firing Notification

TCS and Locations. The 619 TCS and the 620 TCS with their detachments covered the Vietnam area of operation as described below.

619 TCS. The 619 TCS had responsibility from the Delta to Ban Me Thuot in the Central Highlands. The 619 TCS (CRC call sign PARIS) was located near Saigon. In support of the tactical mission stated above, PARIS controllers provided timely and accurate information to aircrews, performed handoffs to the Forward Air Controllers, performed refueling hook-ups and provided radar monitoring for MSQ missions. Detachments were located as follows:

• Detachment 9, 619 TCS Ban Me Thuot, RVN, call sign PYRAMID CONTROL (CRP)
• Detachment 11, 619 TCS Hon Tre Island, RVN, call sign PORTCALL (CRP)

620 TCS. The 620 TCS was responsible for the area from Pleiku to the DMZ and was headquartered at Monkey Mountain Air Station outside of Da Nang. Call sign for the CRC operated by 620 TCS was PANAMA.

Also on the top dias at Monkey Mountain was the Tactical Air Control Center, North Sector (TACC-NS) (Call sign MOTEL). This was the location from which missions in North Vietnam, including SAR were monitored and controlled. On the top dias there was also some radar equipment that was used to monitor North Vietnamese aircraft movements.

A detachment of 620 TCS was located at Pleiku AB, RVN, call sign PEACOCK CRP.

621 TCS. The 621 TCS supported tactical air operations in Thailand Detachments of interest were:

• Detachment 3, 621 TCS, Ubon, Thailand, call sign LION Control.
• Detachment 4, 621 TCS, Udorn RTAB, Thailand, BRIGHAM Control
• Detachment 4, 621 TCS, Khao Khieo RTAB (Green Hill). CRC, call sign DRESSY LADY. Dressy Lady was located about midway between Bangkok and Korat in a park run by the Tourist Organization of Thailand (TOT).
• Detachment 5, 621 TCS, Nakhom Phanom RTAB, Thailand, CRP, call sign INVERT.
• Detachment 8, 621 TCS, Phitsanulok RTAB, Thailand, CRP. An MPS-11 Primary Search Radar was apparently located at Phitsanulok RTAB.

Mission of the TASS. The mission of the TASS was to:

• Provide visual reconnaissance and airborne Forward Air Control support of tactical offensive operations.
• Provide theatre indoctrination flight checkouts in assigned aircraft for all assigned and attached personnel.

Location of the TASS. TASS and locations in 1970 were as follows:

• 19 TASS was based at Bien Hoa AB, RVN
• 20 TASS was based in Da Nang supporting I Corps
• 21 TASS was based at Pleiku AB, RVN
• 22 TASS was based at Bien Thuy AB, RVN
• 23 TASS was based at Nakhon Phanom, RTAB

505th Tactical Control Maintenance Squadron was based at Tan Son Nhut AB, Saigon, RVN.