1. BACKGROUND AND ENVIRONMENT.
a. TACAIR support available to ground commanders in the RVN far exceeds that which has been available in any past conflict in which US forces have been involved. The almost complete lack of sophisticated enemy air defense in the RVN has allowed the use of TACAIR en masse with extreme accuracy. TACAIR aircraft in use in the RVN are provided by the USAF, the USMC, the USN, the Royal Australian AF, and the VNAF. The Commander, 7AF, in his role as single manager for air in the RVN, controls all FWMAF and US TACAIR assets, except those of the USN. The Navy provides 7AF with a daily number of sorties that will be available for commitment and these aircraft are provided to 7AF for employment. The VNAF manages and controls all of its assets. However, US, FWMAF, and VNAF TACAIR assets are all controlled and single managed by a joint combined 7AF/VNAF TACC at Tan Son Nhut Air Base. Figure C-1 shows the geographical deployment and location of facilities which control and direct TACAIR in the RVN.
b. In addition to the CAS provided to ground forces, 7AF conducts a DAS program designed as an interdiction campaign against enemy lines of communication and base areas in the RVN.
c. A most important type of air support, other than TACAIR, in the RVN is the massive B-52 strikes in a saturation bombing role. These B-52 strikes are under the operational control of SAC. The detailed planning of the B-52 strikes is done by SAC representatives at 7AF HQ. The decisions on where to place B-52 strikes are made at MACV.
d. Most TACAIR strikes are controlled by an airborne FAC. In the RVN, the FAC is airborne so that he can see both the target and the strike aircraft. He uses the O-1 Bird Dog, O-2A, and OV-10 Bronco light aircraft equipped with FM, VHF, and UHF radios and armed with flares and target-marking smoke rockets and smoke grenades. The other method of providing CAS is by the use of radar-controlled all-weather strikes, referred to as Combat Sky Spot. This method can be used under adverse weather conditions and at night and is executed similar to the B-52 strikes, i.e., with no warning to the enemy.
2. THE TACAIR CONTROL SYSTEM.
(1) TACS in the RVN is designed for comprehensive and responsive control of all TACAIR. It is a closely-knit composite of 7AF/VNAF/ USMC personnel, equipment, and operations centers. In addition to controlling 7AF, VNAF, and USMC (strike and reconnaissance only) air operations, the TACS coordinates and integrates USN and SAC operations in the RVN.
(2) A separate but allied system, the AAGS, provides for processing preplanned requests for air support and rapid exchange of battle information. The two systems, TACS and AAGS, so parallel each other that there is rapid coordination of all air and ground operations.
b. Organization of the TACS.
(1) The TACS has the characteristic and advantage of flexibility to fit any tactical situation. It provides for centralized direction while still permitting decentralized execution of specific operations. The system has proved its responsiveness to ground commanders; the reaction time to requests for immediate air strikes is usually less than 40 minutes.
(2) The TACS is centered around a joint combined VNAF/USAF/USMC operations center at Tan Son Nhut Air Base, the TACC. The schematic outline of this system is shown below, in Figure C-5.
Figure C-5 : Tactical Air Control System (TACS)
Its purpose is to coordinate and control the total US and RVN air effort. There are several units and agencies below the TACC level that are involved in daily execution of air-ground operations. The 7AF provides the equipment and the TACP personnel who work closely with ground commanders. The USMC uses its own equipment and personnel. There are four DASCs operationally subordinate to the TACC. Three of them are combined USAF/VNAF centers (I DASC, II DASC, and III DASC) which support US, FWMAF, and ARVN ground commanders in ARVN I CTZ, II CTZ, and III CTZ. There are no US or FWMAF ground forces supported by US TACAIR in ARVN IV CTZ and IV DASC is entirely under VNAF control.
(3) USAF TACPs, operating under each DASC, are positioned with the ARVN corps , divisions, and regiments and the I and II FFORCEV divisions and brigades, as shown below, in Figure C-6. The responsibilities and manning of the TACPs vary, depending on the level of assignment. Each TACP includes an ALO and/or FAC, radio operators, FAC aircraft, and a vehicle with UHF, VHF, FM, and SSB radios.
Figure C-6 :
(4) The USMC provides its own ALOs, TACPS, and FACs to work with its ground units.
(5) Radar coverage is basic to the operation of the TACS. Sites are located throughout the RVN for complete coverage. For radar control purposes, the RVN is divided into two sectors; each sector contains a large high-performance radar at a CRC. Aircraft track data at the CRC is augmented by similar information provided by outlying radars at CRPs. The USMC operates one CRP and several TPQ-10 sites (the USMC equivalent of the USAF MSQ-77 radar bombing equipment).
c. Functions and Operations of the TACC.
(1) The TACC, acting for the 7AF commander in his capacity as MACV Air Force Component Commander and the DEPCOMUSMACV for Air Operations, has responsibility for running the air war in the RVN. The TACC performs several functions:
(a) It plans, directs, and coordinates all US, VNAF, and FWMAF TACAIR operations in the RVN.
(b) It publishes fragmentary (frag) orders to the agencies concerned, including the lst MAW in I CTZ whose strike and recon aircraft are tasked by the TACC.
(c) It directs, monitors, and diverts strike aircraft as necessary.
(d) It establishes policies and procedures governing the operation of the TACS.
(2) The four DASCs are operationally subordinate to the TACC and serve primarily as extensions of the TACC. They provide a fast reaction capability to satisfy immediate requests from ground commanders for CAS, TACAIR recon, and emergency airlift (not considered further here). They also provide minute-to-minute coordination between the ground commanders in their area and supporting air elements, not only strike aircraft but recon, herbicide, PSYOP, and B-52 aircraft as well.
(3) To fill an immediate request, the DASC may, with Army/USMC approval, divert TACAIR from preplanned missions enroute to the target. In many cases there will be enough airborne aircraft on missions of lower priority to provide diverts, and these result in a quicker response than scrambled aircraft. With one exception, the DASCs do not have authority to scramble alert aircraft - I DASC is allocated USMC ground-alert aircraft for scramble purposes and need only inform the TACC of their launch. If a DASC cannot fill an immediate request by diverts within its area of responsibility, it will request the TACC to scramble ground-alert aircraft. The TACC may elect to scramble aircraft or to divert strikes from an adjacent CTZ.
(4) The TACP provides an AF communication system down to the brigade level. An ALO, who is a key member of the brigade commander's staff, heads the TACP. The ALO attends the brigade commander's meetings, briefs on air activity in the area of interest, and advises on the use and capabilities of TACAIR. Also, the ALO is a senior FAC and the supervisor of the FACs in his TACP. These FACs are AF pilots who perform several vital missions from their airborne positions in light observation aircraft. The FACS:
(a) Maintain close contact with local ground commanders.
(b) Help keep ground commanders in contact by providing airborne radio relays.
(c) Direct air strikes.
(d) Perform BDA and forward BDA reports.
(e) Perform VR during daily airborne patrols of their sectors.
(5) The radar and extensive communication network of the TACS make possible the quick responsiveness of the system. All aircraft on strike missions are picked up on radar and identification is usually established within five minutes after takeoff. Radar direction is provided to the pilot to the rendezvous point with the FAC. After the strike, radar contact is reestablished with the controlling radar facility for the return to base. Should an aircraft need emergency assistance, the radar network can provide vectors to the nearest suitable base or bailout area. Strike aircraft are also provided inflight radar advice on possible conflicting air traffic and warnings on artillery fires.
Vietnam Lessons Learned No. 77: Fire Support Coordination in the Republic of Vietnam. United States Military Assistance Command, Vietnam, 20th May 1970