4. DIRECT AIR SUPPORT.
(1) DAS is a 7AF interdiction campaign against enemy lines of communication and base areas in the RVN. This program complements other interdiction efforts, striking lines of communication near the borders of Laos and Cambodia. The concept of this program is to strike lines of communications, bridges, truck parks, storage areas, and other related facilities to support friendly ground operations and to hamper enemy re-supply of his forces in the RVN. Tactics consist of a concentrated effort on a selected area for as long as required, then a shift to other priority target areas. DAS sorties will not be allocated in a harassment role to strike suspected enemy areas not confirmed by hard intelligence.
(2) To insure flexibility for this interdiction campaign. ARVN Corps commanders have established SSZs and authorized strikes into those areas without further GVN political clearance.
(3) DAS resources managed by 7AF are also allocated on a daily basis to -
(a) Provide escort for suppression of ground fire on all herbicide missions and cargo drop operations into areas of known enemy opposition.
(b) Support operational requirements for special missions and exercises directed by 7AF.
b. FAC-Controlled Strikes
(1) Preplanned DAS missions directed by FACs are planned, fragged, and executed in the same way as are preplanned CAS strikes. Targets are nominated by both ground and AF commanders. As with CAS missions, all strikes must be approved by Vietnamese officials, either on an individual basis or through pre-delegated authority to a ground commander, and coordinated with the fires and maneuver of the ground commander. Immediate DAS strikes are also made against a variety of targets in a manner similar to immediate CAS missions.
c. Ground-Controlled Radar Bombing
(1) As a backup for FAC-directed strikes, the USAF MSQ-77 (Skyspot) and USMC TPQ-10 ground-controlled radar systems can be used to carry out DAS missions. (See Figure C-2l.) These systems are not intended to replace visual bombing, but rather as a complement to it during poor weather and darkness. They are also used for precise target acquisition during good weather when a FAC is not available or his use is impractical.
(2) The Skyspot radar is a modification of the radar bomb-scoring unit used by the SAC for many years to plot simulated bomb impact points in training SAC combat crews. This radar depends on line of site and therefore is limited by earth curvature and other terrain obstructions.
(3) There are enough radar sites in the Skyspot and TPQ-10 system-. to provide overlapping coverage of all the RVN. Thousands of sorties have been controlled by these units at night and during poor weather. Although mainly used for preplanned night strikes in a harassment and interdiction role, radar-directed strikes have been used effectively on an immediate basis and in CAS of engaged ground commanders. On several occasions, ordnance has been delivered as close as 250 meters to friendly forces when they were in difficulty and visual strikes could not be made.
(4) Preplanned radar-directed strikes are fragged by the TACC along with other missions. Ordnance always consists of bombs; napalm is not used. After takeoff, the strike aircraft are passed from the appropriate CRC/CRP to a skyspot or TPQ-10 station which directs the strike. The station provides heading, altitude, and airspeed directions to the pilot and, using bomb release tables and wind data, guides the strike aircraft by radar plot to a computed bomb release point.
(5) Aircraft can be diverted to immediate strikes via radar direction after coordination between the DASC and the radar station. The DASC must provide the target coordinates to eight digits (10 meter square), delivery heading and allowable deviation, position of the friendly ground commander, and TOT requirements to the controlling radar station.
d. B-52 Strikes.
(1) SAC B-52 forces also support ground commanders in the RVN, which is carried out through a systematic program of saturation bombing of area targets. The B-52 aircraft have been modified to carry up to 108 500-pound bombs, internally and externally - a total of 27 tons. Various load combinations of 500, 750, and 1000-pound bombs are used with fusing to fit the target and the terrain.
(2) Command and control of the B-52s used over the RVN are unique. Their control does not fall totally under the 7AF Commander; however, in his role as DEPCOMUSMACV for Air Operations, he does exercise the necessary operational control. The tactics, techniques, and operating practices of the B-52s are determined entirely by the SAC.
(3) Under usual circumstances, COMUSMACV is the approving authority for all B-52 strikes in the RVN. Targets are selected from requests received from the corps (RVN) and FFORCEV or XXIV Corps (US) ground commanders, and others (including intelligence agencies) and arranged on the basis of priority. The desired TOT, ordnance, grid coordinates, number of aircraft, and other standard strike criteria are established and a strike request giving these data is sent to the SAC by 7AF. SAC has operational control of the B-52s and issues the execution orders for the strikes.
(4) The B-52s do not operate under the TACS, in the usual sense of the term. The flights are made on an altitude reservation basis through agreement with the RVN aviation agency. They are radar monitored by CRCs and CRPs throughout the RVN to provide safe separation from TACAIR traffic. Missions are normally fragged 24 hours in advance but the ground commander in contact can have B-52 support within a few hours from a SAC alert force or by diversion of B-52s from another target.
(5) Since June of 1965, the tremendous destructive power of the B-52s has been used to strike enemy base camps, supply points, troop concentrations and other installations and facilities. Psychologically, too, the B-52s have had a damaging effect on the morale of the enemy, as verified by captured enemy and other sources. In some cases, it has taken several days for survivors of B-52 strikes to regroup as an effective force.
a. Introduction. Most of the aerial recon done in the RVN is in support of ground commanders. Recon sorties are also flown for BDA after air strikes. There is also a large number of sorties flown on a daily, continuous basis to search out new enemy activity. USMC aircraft, such as the EA-6A, and USA aircraft, such as the OV-1 and the O-1, are used for a large number of recon support requirements; this support is provided on a direct/general support basis and is directly responsive to the ground commander at regiment/brigade and higher level. However, many requirements, such as photographic and infrared coverage of large areas, are beyond the capability of these systems and are provided by those of the AF. The aerial recon discussed here is limited to that provided by the AF and is included because of its direct contribution to the ground commander's mission and its similarity to TACAIR support.
b. Aerial Recon Sensors. There are five types of recon sensors used in the RVN: photographic, electronic, infrared, SLAR, and visual. (See Figure C-25) The first four are functions of a specific unit. VR is a function of all aircrews flying over the RVN; the FAC is a major contributor of VR.
(1) Photographic recon gives a graphic source of information for detailed study and analysis. Both black-and-white and color photography, including camouflage detection, are available. Area, point, and strip coverage are the principal types available. Photo recon at night can also be done, using flares to light the area being photographed.
(2) Electronic recon is used to locate and analyze sources of electromagnetic radiation. At present, in the RVN, it is used mainly to locate control and communication systems, both day and night. Should the enemy attain the capability of gun-laying antiaircraft radar, this form of recon would be used to search them out.
(3) Infrared recon is used at night to record on film any areas or objects that emit heat. Such emissions may indicate enemy activity.
(4) SLAR can locate fixed and, to some extent, moving targets along routes of infiltration, such as trails, canals, rivers, and coastlines.
(5) VR is a rapid way to get to current information. Much VR in the RVN is done by the airborne FACs operating throughout the country. About 70% of FAC sorties are for VR purposes. Each FAC is assigned a specific sector, which he systematically patrols on a daily basis. From these daily flights, a pattern of the habits of the populace becomes apparent and any change in this pattern is good cause for a closer look. When the pattern changes, the FAC reports it to the province chief, who may join the FAC on his next flight. A significant amount of intelligence is gathered in this manner. Upon landing, the FAC is debriefed and the information passed to the DASC. The information from the various TACPs is consolidated at the DASC and submitted to the TACC. Items include enemy activity, structures, base areas, logistics, infiltration routes, and BDA. The resulting DISUM is used to develop targets, verify other intelligence, determine the effectiveness of weapons used against the enemy, and to degrade targets which have been struck. Also, the information is used to compile data on the results of specific air strikes, including enemy casualties inflicted by aircraft weapons. The VR reporting net is shown below, in Figure C-26.
Figure C-26 : Visual Reconnaissance Reporting Net
c. Recon Requests.
(1) Specific requests for aerial recon usually begin with the ground commander. AF recon officers assigned to the DASCs, along with unit ALOs, assist ground commanders in requesting aerial recon. These officers also advise and assist the S-2 staff on matters pertaining to aerial recon, review recon requests, and arranged for artillery coordination for all recon missions flown in their area of responsibility.
(2) Recon requests are processed in roughly the same manner as are requests for TACAIR support, i.e., through corps (ARVN) and the FFORCEVs and XXIV Corps (US). In addition to those from ground commanders, other requests are originated by various intelligence agencies, e.g., 7AF DCS/Intelligence, CICV, and MACV Studies and Observations Group. Recon requests are sent to the MACV TASE where a MACV J-2 Air Officer evaluates the request. If approved, it becomes a requirement and is passed to the 7AF In-Country Recon Staff. Each request includes the type product desired, scale, date no longer of value, and priority. The In-Country Recon Operations Branch prepares the frag order that tasks the recon unit, the 460th TRW, which groups assigned targets according to priorities, the forecasted weather, and system capabilities.
(3) Recon missions are monitored by elements of the TACS after coordination with FSCCs to provide artillery clearance. Usually, each mission is assigned several target areas. Recon operations continue around the clock, using infrared and radar at night to complement photography.
d. Recon Exploitation.
(1) Once the recon aircraft has returned, the exploitation of the data begins, to include getting it to the requesting ground commander. In the case of photography, the film is processed immediately by the PPIF attached to the tactical recon squadron. The PPIF prepares a "trace" which specifically marks the location of the photos, makes an IPIR, and produces the required prints and duplicate imagery. The IPIR is provided to the original requester as a spot report, by teletype or telephone. Army Recon Liaison Officers located at the 460th TRW assist in getting this data to field units. The imagery and "trace" are flown to the requester. Army MIBARS detachments, located in each CTZ, look at this data in more depth and prepare a SUPIR.
(2) The ground commander uses spot reports, photos, the IPIR, and the SUPIR in determining whether to strike a target, where, and with what type munitions. He may decide to use artillery rather than to request TACAIR. If, for example, the recon products requested by CICV or 7AF DCS/Intelligence indicate a profitable target, the decision to strike must still come from the ground commander. Should a worthwhile target be found as a result of a 7AF DCS/Intelligence request, the information is passed to the appropriate DASC, then to the appropriate ALO who recommends that the ground commander request a strike.
(3) The intelligence agencies, such as CICV and 7AF DCS/ Intelligence may develop a B-52 target after studying photos, infrared recon, information from agents, road watch reports, and VR. These agencies may also develop strike requests for special operations. These are generally the only strike requests generated by intelligence agencies and forwarded directly to the TASE.
e. Other Recon Forces. USMC air units in I CTZ and VNAF also provide valuable recon to complete the intelligence picture compiled by the 7AF and Army aircraft. The J-2 element of the TASE supports not only the US Army and the ARVN, but also FWMF.
6. SUMMARY OF TACAIR SUPPORT.
a. TACAIR operations are being conducted in the RVN within the framework of a system which evolved from lessons learned in World War II and Korea; this is the TACS. There is a greater amount of centralized control of TACAIR in the RVN than was originally intended for the TACS. This is due to a formidable air capability being concentrated in a small geographical area - reaction from an air base to a target is counted in minutes - and an extensive communications net makes possible the command and control of this capability from a single point.
b. TACAIR in the RVN has been tailored to operate within the relatively permissive environment that exists because of friendly domination of the air. This is the key to departure from doctrine or classical methods of operation. Certain tactics and techniques developed and in daily use in the RVN would not be feasible in another theater where the enemy has his own air capability and more effective air defense weapons. We have been permitted to develop and use nonstandard tactics and weapons systems. The unrestricted use of the airborne FAC is one example - the ability to put him above terrain obstacles and ground foliage, where he can pinpoint both friend and foe, has been invaluable to the friendly ground commander. The Spooky gunship is another example.
c. The B-52 operations have seriously hampered the enemy's ability to concentrate men and supplies. These raids, and the use of radar-controlled strikes, have greatly aided interdiction in the RVN - again with the objective of supporting the ground commander.
d. Likewise, most of the aerial recon effort in the RVN is in direct support of the ground commander. The nature of the war makes it extremely difficult to follow the movement and intentions of the enemy. This problem has been greatly simplified by using the airborne FACs to police their sectors on daily flights; any change in the normal pattern of the countryside, such as lack of people in the fields, fresh excavations, or evidence of unusual travel along the trails may indicate enemy activity. A ground commander can obtain specific recon of a target or area by requesting it in much the same way as he would request an air strike.
Vietnam Lessons Learned No. 77: Fire Support Coordination in the Republic of Vietnam. United States Military Assistance Command, Vietnam, 20th May 1970