December 8, 2000 Evolution of the Marine Air Command and Control System (MACCS)

OVERVIEW

The argument could probably be made that the elements which make up what we know today as the Marine Air Command and Control System (MACCS) had their beginnings with the first employment of Marine tactical aviation. Certainly operations by the First Marine Aviation Force in France during World War I required some planning and coordination. It is unlikely that these early Marine aviators just decided one day to launch to see what would happen as they flew over the trench-bound infantry units. There was most certainly some planning for missions flown during the “Banana Wars” in Central America in the “Twenties” by such famous Marine aviators as Christian Schilt, who was awarded the Medal of Honor for his actions in that conflict.

But it seems that Marine aviation command and control was not thought of much until the conflict in the Pacific Theater during World War II. Certainly all Marines are aware of the employment of Marine aviation in defensive operations at Wake Island and Midway, where fighter aircraft and ground-based “anti-aircraft artillery”, mostly .50 caliber water cooled machine guns, provided area and point defense against enemy air attacks. Are there any Marines who are not aware of the “Cactus Air Force” which operated from Henderson Field on Guadalcanal in support of the First Marine Division? Or of the close air support provided on Peleliu when Marine Corsairs dropped napalm and high explosives on Bloody Ridge? And again in Korea in 1950 when Marine aviation made daytime operations by Chinese Communist forces against Marines at “The Reservoir” the functional equivalent of suicide? All these operations required some level of command and control, even though that term was not in widespread use at the time.

It seems fitting that MACCS Marines should have some idea of where we came from and where we are going. Not in the sense of a separate “community”, but recognizing our heritage as a part, an important part, of the Marine Air-Ground Team. It also seems fitting that the story of who we are, where we have been, and where we are going should be documented, not by a military historian, but by Marines who have served in the MACCS. Those of us who have been involved in the effort in the past should provide to those who have followed us and to those who will come in the future, the written equivalent of an “oral” history by taking pen to paper, producing recollections based on our personal experiences of significant events and developments. By definition, such recollections may differ greatly from the “official” view of developments since, in large part, these recollections will come from the senior staff NCO/company grade officer level, not from official high level documents. They will be flavored by opinion – but what human endeavor is not, in some fashion, opinionated.

Perhaps the effort to document the evolution of the MACCS will be looked upon as “blowing our own horn” and that is probably true. So be it, but MACCS Marines have much of which to be proud.

In describing the evolution of the MACCS based on personal reflections, several organizational approaches are possible. Because there will be inputs provided by multiple sources at different times, documenting this evolution in a chronological sequence would be difficult and would probably require a massive editing effort. A simpler approach might be to organize the inputs along the lines of the two major mission areas of tactical aviation – MACCS support of offensive air operations and of defensive operations. The important thing is to get started on the effort while those who have been participants in the evolution of the MACCS over the last 50 years or so are able to set down their experiences.

Support of Air Defense Operations - Evolution of the Tactical Air Operations Center (TAOC)

Background – The Counter Air Operations Center (CAOC)

Although there had been advances in air defense operations from the end of World War II until the mid-1950s, the principal air defense agency of the ‘50s, the CAOC, was not all that different from the air defense centers of WW II. Marine Corps Ground Intercept Squadrons (MCGIS) had been redesignated as Marine Air Control Squadrons (MACS). Radar, IFF and ground-to-air communications were certainly more advanced. However, the operations center itself was probably not significantly different from the operations center of the ‘40s. A primary air search radar (AN/MPS-11A) and two smaller “gap-filler” radars (AN/TPS-15) and their associated Mark 10 IFF equipment provided radar and IFF video for display on radar “scopes” (AN/UPA-25) located in the operations “bubble” (AN/TSQ-6). Two-dimensional air track information, range and bearing from the CAOC, was determined from the radar video displayed on the “scopes”.

Air track initiation and position updates were provided by surveillance operators, who typically manned one or two of the radar “scopes” and called position information via the intercom to plotters who entered and updated air track information by grease pencil entries written backwards on a vertical Plexiglas display, visible to all operators and controllers within the CAOC “bubble”. Altitude information on a particular track was obtained from a “nodding beam” (vertically scanning) height finding radar (AN/MPS-4) and provided by a height finder operator only upon a request from a surveillance operator or air controller. Airfield and aircraft status and callsigns, along with weather and CAOC communications status, were also entered and updated by the plotters who posted this alphanumeric data by writing backwards on Plexiglas status boards located on either side of the vertical situation display. Figure 1 shows a typical layout of the CAOC as it existed in the mid-to-late 1950s.

Identification of air tracks as friends was generally based on track location, supplemented by the Mode 1 response to Mark 10 IFF interrogations, which resulted in the display of an IFF vide arc, range coincident with the radar video. Identity of specific friendly aircraft was accomplished by a controller request for the pilot to switch his transponder to Mode 2 (“squawk flash”), which resulted in the display of two IFF video arcs.

Intercepts were conducted by air controllers who plotted targets and fighters by grease pencil entries on their radar “scopes”. Guidance information was calculated manually by air controllers based on the fighter/target geometry and called to the pilot via the CAOC UHF radios.

Air controllers were almost exclusively reserve officers on active duty for three year tours because there was no career air control field for unrestricted officers. Since these officers did not arrive at the MACS until they had completed OCS, Basic School and had attended an air controllers training course, they usually had only enough active duty time left for a tour in one operational squadron. Staff NCOs and an occasional warrant officer were the only “career” air controllers. With the replacement of the two seat F-3D with the single seat F-4D in the late-50s, several Staff NCO airborne intercept operators (AIOs) were reassigned to the MACS, increasing somewhat the level of air controller proficiency. Squadron commanders, executive officers and operations officers were typically aviators, many of whom were no longer on flight status.

In the late ‘50s, some improvements were made to the CAOC equipment. AN/MPS-4 height finder was replaced by the AN/MPS-16, which provided more accurate altitude information. More importantly, a Selective Identification Feature (SIF) was added to the Mark 10 IFF sub-system. The SIF provided specific coded responses from the aircraft so that a “code of the day” in Mode 1 helped in the identification of assumed friends and the Mode 2 (Personal Identity or PI) response was used to identify particular aircraft. While these improvements, particularly the SIF, increased the capability of the CAOC, the agency was still not far removed from the WW II capability.

The accompanying photograph [note: Memo unable to include photos & figures due to PDF to Web page transition and Pirate’s lack of webmaster skills] shows the field installation of two major equipment of a CAOC, with the AN/MPS-11A in the foreground and the operations shelter, AN/TSQ-6, in the background. The photograph was taken in September 1958, and shows the MACS-1 operating site on Monkey Mountain outside Kao Hsuing, Republic of China (ROC) on Taiwan. Marine Aircraft Group 11 (MAG-11) with its organic air control squadron, MACS-1, was deployed from its garrison location at Atsugi, Japan to Taiwan in response to a threat to the ROC by the People’s Republic of China (PRC). PRC forces had begun an artillery bombardment of two islands, Quemoy and Matsu, located just off the coast of the PRC, and it was feared that hostilities between the PRC and ROC were possible. As a sign of U.S. support of the ROC, ships from the U.S. Seventh Fleet were sent to patrol the Straits of Taiwan to discourage a surface attack of Taiwan. MAG-11 was deployed to supplement the ROC Air Force (ROCAF), which had no all-weather fighters. Two MAG-11 fighter squadrons, VMF(AW)-115 and VMF(AW)-314 were equipped with the new Douglas F-4D “Skyray”, a single seat all weather fighter, while the third squadron, VMF-323 flew the North American FJ-4 “Fury”, which was similar to the F-86 “Saber Jets” flown by the ROCAF. During the deployment of MAG-11 to Taiwan, MAG-14 with its organic MACS-2, moved to Atsugi from its garrison location at Kaneohe Bay. As the situation cooled, MAG-11 and MAG-14 returned to their respective garrison locations in March 1959.

Requirement for an Automated Marine Corps Area Air Defense System

As can been seen from the description of the CAOC, for most of its history what we now know as the MACCS developed in an evolutionary manner. However in the late 1950s, the decision to automate those portions of the air command and control system related to area air defense represented a revolutionary change to the existing structure. This decision was prompted partly by the proposed introduction of computer automation into the U.S. Navy under the Navy Tactical Data System (NTDS) program. Under the NTDS concept, data from sensors on multiple seaborne and airborne platforms would provide surveillance information on air, surface and subsurface tracks. Information would be shared within the fleet through the use of several computer-to-computer digital data links. An omnidirectional data link, designated Link 11, would support the sharing of real-time data among ships and surveillance aircraft. An aircraft control link, Link 4, would provide data link control of fighters. Since the automation of all U.S. Navy ships would be prohibitively expensive, some smaller surface ships would receive data only over a non-real-time teletype network, designated Link 14. Data link formats and protocols were based on standards defined within the North Atlantic Treaty Organization (NATO) because U.S. Navy ships operating in the Atlantic and Mediterranean would be part of that air defense network.

This decision by the Navy required a commensurate change within the Marine Corps if the Marine mission as a landward extension of sea power was to be accommodated. As a result, in 1957 a study contract was awarded to define the structure and implementation of a Marine Tactical Data System (MTDS). This program would introduce automation into the Marine Corps in the area of air defense command and control and would provide an automated interface of the land-based MTDS with the ship based NTDS.

In addition to the requirement to achieve Navy/Marine Corps interoperability, there was a recognition that higher aircraft speeds and increased single weapon lethality required a shorter system reaction time than that achievable by the then-current “manual” area air defense structure as implemented in the CAOC. System reaction time to air threats could be significantly reduced if the routine, repetitive functions of air defense (e.g., track initiation and position updates, friend/non-friend categorization based on IFF responses, etc.) could be automated. This automation would leave more time for the accomplishment of decision-making functions (e.g., threat evaluation and weapon assignment) by system operators. Once weapon controllers had made assignment decisions, computers could help in the solution of the attack geometry and the calculation of command data for the interception and destruction of air threats. Of course, all automated functions would have to be subject to override by humans and a manual “back up’ capability was required in case of failure of the automated capability.

The MTDS Concept

Under the MTDS concept, area and point air defense within the Marine Air-Ground Task Force (MAGTF) was to be combined in a new agency – the Tactical Air Operations Center (TAOC). The TAOC would automate, where feasible, the command and control function formerly accomplished for both fighter aircraft at the “manual” CAOC and for newly introduced surface to air missiles at the Anti Aircraft Operations Center (AAOC). Command functions would continue to be accomplished by the Marine Tactical Air Commander and his staff at a Wing-level Tactical Air Control Center (TACC), which would also provide the MTDS-NTDS voice and data link interface. This concept is shown graphically in Figure 2. (It should be noted that Figure 2 and all subsequent figures show operational interfaces and not necessarily command relationships. Also, for simplicity, TAOC-SAM and TAOC interface to controlled aircraft is shown for only one TAOC, although all TAOCs had this capability.)

To provide for deployment versatility, all MTDS program equipment was to be contained in helicopter transportable shelters, with an initial weight limit of 2500 pounds. This presented a major challenge to the system design in that major system components – radar/IFF processors, computers, operator displays and voice and data link communications equipment had to be allocated and packaged so as to meet equipment shelter weight restrictions while minimizing interconnecting cables.

MTDS Research and Development Program

Following the approval of the concept defined in the MTDS study, the Marine Corps embarked upon a research and development program to field sufficient equipment for the conduct of operational tests. The project officer at Headquarters, CMC (A04C), was then-Major Edward S. Fris. A contract for R&D versions of MTDS equipment was awarded in the late 1950s by the procurement agency, the U.S. Navy Bureau of Ships, BuShips, Code 675H. The award of a contract for a major electronic system development was, in itself, a significant departure from the Marine Corps approach taken in the past. Except for the development and fielding of amphibious assault vehicles prior to and during World War II, the Marine Corps approach had been mostly to let other services take the lead in development efforts and to join in on procurement during the production phase. For example: The Marine Corps bought tanks, field and anti-aircraft artillery systems developed by the U.S. Army; fighter, attack and support aircraft developed and fielded by the U.S. Navy; and air search radars developed for the U.S. Air Force. While Marines may have been able to exert some influence on the operational characteristics of these equipments, the requirements generally reflected the needs and employment doctrine of our sister services. This was not to be the case for the MTDS Program, and as a result, getting and keeping development and production funding for MTDS equipment became a major effort at Headquarters, Marine Corps as the other services, particularly the Air Force, constantly challenged the need for the Marine Corps to develop and field a system addressing air command and control requirements, an area which the Air Force viewed as “theirs”.

Due to its location in the proximity of the principal MTDS R&D contractor, MACS-3, located at the Marine Corps Air Facility at Santa Ana, CA, was detached from the Third Marine Aircraft Wing (3MAW) in early 1961, designated as the MTDS Test Unit (MTDSTU) and placed administratively under El Toro-based Aircraft, Fleet Marine Forces, Pacific (AirFMFPAC). MACS-3 was tasked with performing all necessary tests to determine the operational and maintenance suitability of the two major systems comprising the MTDS. The commanding officer of MACS-3 was then-LtCol Fris, who had assumed command following a stint as the Marine Corps Representative at the MTDS contractor’s facility from mid-1960 until equipment delivery.

In the test and evaluation effort, MACS-3 reported to the Marine Corps Landing Force Development Activity (MCLFDA) in Quantico, the successor to the Marine Corps Equipment Board (MCEB) and the predecessor of the Marine Corps Development Center (MCDC). MACS-3 would continue to act as the principal MACCS hardware and software test and evaluation facility until the early 1970s when the Marine Corps Tactical Systems Support Activity (MCTSSA) was established at Camp Pendleton. MCTSSA was created as an expansion of the existing amphibious assault vehicle test facility in order to combine all Quantico West Coast test and evaluation efforts into a single unit. Subsequent to the designation of MCTSSA, MACS-3 at Santa Ana was re-designated as Sub Unit-1, MCTSSA, and was eventually deactivated and all tactical system support tasks were accomplished at Camp Pendleton.

Delivery of MTDS R&D systems began in September 1961. One system, designated Air Command Central (ACC), AN/TYQ-1(XN-1), would be located at the automated TACC, now designated as the Tactical Air Command Center, and would provide the facilities to receive and display the real time air picture based on data received over automated interfaces with the newly designated TAOCs. In addition, a Beach Relay Facility was included at the TACC to provide the data link interface between the MTDS and the NTDS over Link 11. One ACC was delivered to MACS-3 for test and evaluation, along with a cadre of trained Marines.

Two other equipment suites were delivered for evaluation for use at the TAOC. These equipments were designated Air Operations Central (AOC), AN/TYQ-2(XN-1 and XN-2). One system (XN-1) was installed at the main MACS-3 site at MCAF, Santa Ana and the second (XN-2) was delivered to Sub Unit 1, MACS-3 at MCB, 29 Palms. Testing of the Santa Ana based system primarily evaluated the ability of the AOC to generate a correlated air picture based on inputs from several air search radars and IFF equipment and to exercise control of aircraft by both voice and data link communications. The system installed at 29 Palms was evaluated to determine the ability of the AOC to interface with Marine surface to air missile (SAM) units. All three systems, ACC and AOCs, were tested to evaluate the ability to pass voice and digital data communications among the elements of the MTDS, and to determine if the systems could be operated and maintained by Marines. Testing continued through 1962, leading to a production decision in 1963.

MTDS Production

As a result of operational testing, significant changes were made to the design of the AOC and ACC equipment. The most significant of these changes addressed operational deficiencies in the area of digital data exchange that, in turn, affected the conceptual MTDS system architecture. There were at that time, of course, no data exchange standards with which all U.S. services were required to comply. Each of the services implemented unique data links, with little regard for inter-service or international data exchange. As a result, in the original MTDS system design, data was passed among the three TAOCs planned for each MAW and from each of the TAOCs to the TACC over an Inter Center Data Link (ICDL). The ICDL, although Marine-unique, was designed to include all data fields necessary to accommodate data exchange with NTDS on Link 11 via the Beach Relay at the TACC. Unfortunately, an assumption was made during the MTDS study that the MTDS would always be employed as an entity and that the TACC would always be included in the system architecture to provide the linkage of MTDS with NTDS. No provisions were made in the R&D systems for the direct interface of a TAOC with the Navy via Link 11. As a result, for production, a new equipment suite was defined to accomplish this interface in the event that the TACC was either not deployed, or that battle damage to the TACC required the designation of a TAOC as the alternate TACC (ATACC). This new equipment designated Tactical Data Communications Central (TDCC), AN/TYQ-3, replaced the Beach Relay and could be located at either the TACC or at a TAOC. When located at a TAOC, the interface between the AOC and the TDCC would be over an interconnecting cable. Unfortunately, this AOC-TDCC interface became known as the “X Link”, even though it was not a digital data link in the true sense, although all data fields necessary for Link 11 communications were provided. Also unfortunately, for production the designation of the ACC and AOC were changed to Tactical Air Command Central AN/TYQ-1 and Tactical Air Operations Central, AN/TYQ-2, causing difficulties sometimes in distinguishing between the TACC and TAOC as air command and control agencies or as equipment suites. Figure 3 shows the system architecture for the MTDS production systems. Again, the Figure shows information flow and not command relationships.

Another important change for production was the development of a “universal” operator console with a touch sensitive display. In the R&D design, different consoles were provided for surveillance operators and weapon controllers. Surveillance consoles consisted of a radar/IFF video Plan Position Indicator (PPI) display overlaid with a limited graphics display. Designers believed that this was required for the surveillance/ID tasks, including manual track initiation for tracks not “seen” by the computer. It was also assumed that weapon controllers would not require the display radar/IFF video, but would be able to perform their function with only a computer generated graphics display. This approach was found to be unsatisfactory during operational tests. For production, all operator consoles were identical, displaying both radar/IFF video and overlaid with the full range of computer generated graphics. In addition, in the R&D design, an “electronic “pencil” was used at operator consoles to communicate with the computer. This design proved to be unsatisfactory from both ease of operation and maintenance standpoints. For production, the operator displays included a touch sensitive capability, a feature that was unique in tactical systems of the 1960s. These MTDS Universal Consoles are shown in the accompanying photograph. A total of 15 consoles, three installed in each of five operator shelters at the TAOC, more than doubled the number of operator positions which had been available in the CAOC.

Initial plans for production were to procure a quantity of equipment’s to outfit the three active duty Marine Aircraft Wings and one Reserve Wing, each of which included three TAOCs and a TACC. Support of this structure required a total of 12 AN/TYQ-2 for use in the MACS, plus additional sets for maintenance and operator training and a “maintenance float” to include spare systems for periodic refurbishment or to replace equipment losses due to accidents or battle damage. Consequently, the initial buy of AN/TYQ-2 was for 14 systems to equip the three active duty Air Wings and to provide two unsheltered systems for training at Marine Corps Communications-Electronics School (MCCES). Systems for the Reserves and maintenance float would be procured in a follow-on effort. Subsequent reduction in force structure within the MAW to two MACS per Wing allowed the outfitting of all Marine Corps users with this initial buy. In addition to the buy of AN/TYQ-2/TDCC for the TAOCs, four AN/TYQ-1/TDCC equipments were procured for the active and Reserve TACCs.

Fielding of MTDS Equipment

The first production AN/TYQ-2 was delivered to MACS-3 (MTDSTU) for tests to confirm that changes made for production had been properly implemented. This delivery, in March of 1966, was followed by the delivery of an unsheltered system to MCCES at 29 Palms to support operator and maintenance training. In September of 1966, the first delivery to the FMF was made to MACS-4 at Camp Pendleton. MACS-4 was slated to relieve MACS-7 in the Republic of Viet Nam in the summer of 1967.

Deliveries of other AN/TYQ-2s were made to all active duty and Reserve MACS in accordance with a fielding plan. Delays in the deliveries of automated TACC equipment resulted in a period during which the TAOCs were automated while the TACCs operated in a non-automated environment.

The introduction of MTDS equipment into the MACS was accompanied by the fielding of a long-range three dimensional search radar. This radar, designated the AN/MPS-21 in the development phase and AN/TPS-34 for production, provided range, altitude and height on all tracks detected within its surveillance envelope. Fielding of this radar provided the MACS, for the first time, with the capability to have current three dimensional surveillance data within the entire search volume of the primary TAOC radar, with no operator action required to determine aircraft altitude.

MTDS Operation in Southeast Asia

In November 1966 following receipt of MTDS equipment in September, a team from MACS-4 went to Viet Nam to select an operating site for the upcoming deployment. Potential sites in the Chu Lai/Ky Ha, Hue/Phu Bai, and Da Nang areas were evaluated. It was decided that to support adequately operations in northern I Corps, to provide support for aircraft returning to Da Nang and Chu Lai from strikes in North Viet Nam, and to achieve a dependable Link 11 interface with NTDS ships operating in the Gulf of Tonkin (Task Force 77), MACS-4 would locate on the center peak of Hill 647 (“Monkey Mountain”), northeast of the airfield at Da Nang. This site was then the operating site for B Battery, First LAAM Battalion and provided adequate radar coverage both north and south of the mountain range which stretched to the sea in the Da Nang Tactical Area of Responsibility (TAOR), coverage which could not be achieved from sites either north or south of the mountain range.

As an interesting sidelight, when the plan to put the MTDS system in-country became known, the Air Force made a move to have the USMC AN/TYQ-2 provided to them for that deployment. Because of the significant effort that the USAF had made at the DoD level to cancel the MTDS Program and to divert USMC funding to the Air Force, the request was viewed with some humor at HQMC. But not for long! The Marine response was basically that if the MTDS was going to Southeast Asia, it was going with Marines. End of discussion! Thus, another Marine Corps first was achieved – the first deployment of a ground based, automated air command and control system for support of combat air operations.

In the spring of 1967, MACS-7 (Rear) was established at Camp Pendleton, collocated with MACS-4. Non-deployable personnel, primarily consisting of Marines with recent oversea control dates, were assigned to MACS-7 (Rear) and all others were “frozen” for deployment to Viet Nam. A MACS-4 advance party left Camp Pendleton in April, flying to Da Nang to coordinate site preparation on Monkey Mountain with 1MAW. (An MTDS Liaison Office had previously been established at 1MAW Headquarters and was manned by two officers who had been in MACS-3 and were already in 1MAW. - LtCol Walter J. McManus and CWO Normand “Frenchy” Charest).

All squadron equipment except for the TDCC, which was finishing acceptance testing, and remaining MACS-4 personnel embarked aboard ship and in mid-May sailed for Da Nang, arriving in early June 1967. Off-loading was accomplished at the deep-water pier adjacent to the Naval Support Activity (NSA) at Tien Sha, and the equipment was transported by truck to the operating site atop Monkey Mountain. Preparation of the joint MACS-4/B Battery operating site and living area was being done by Seabees and system emplacement and initial check-out was done as site preparation allowed. The MACS-4 TDCC arrived by air shortly after the squadron main body and full MTDS TAOC system capability was realized.

MACS-7, operating from their site at Ky Ha in the Chu Lai TAOR, continued to support 1MAW operations until MACS-4 became operational in July. MACS-7 stood down and relocated to Camp Pendleton. MACS-7 personnel who were not eligible for return to CONUS were transferred to other command and control units within the Wing, including some to MACS-4.

A view of the MACS-4/B Battery operating site is shown in the accompanying photograph. A second photograph shows the MACS-4 TAOC shelters installed in protective aircraft revetment.

With no credible enemy air threat in Southeast Asia, MACS-4 supported operations in all other 1MAW mission areas – flight following/en route control, refueling and return-to-base, SAR coordination, etc. After an initial period during which it was necessary to “sell” MACS-4 capabilities to aircrews, a mutual appreciation of aircrew needs and MACS-4 capabilities developed. A typical preplanned air support mission would come to use virtually all capabilities of the in-country MACCS:

• An F-4B from MAG-13 is fragged for an Air Support Radar Team (ASRT) controlled strike in northern I Corps.

• The Marine Air Traffic Control Unit (MATCU) provides departure control at the airbase at Chu Lai and passes control to the TAOC.

• The aircraft is acquired by TAOC radar. Based on a correlation of the received IFF codes with ATO data previously entered into the TAOC computer, the flight is IDd and the TAOC controller RIOs the flight with the TADC, eliminating the need for the aircrew to change radio frequency to report in to the TADC. (Note that 1MAW established a Tactical Air Direction Center at 1MAW headquarters because the Air Force, as the Air Component Commander for the theater, established USAF TACCs in both the Saigon and Da Nang areas.)

• The TAOC provides flight following and waypoint vectoring services en route to the ASRT area. Data regarding potential flight hazards (SAVAPLANE) are passed from the TAOC to the aircrew based on information which had been received from the Direct Air Support Center (DASC) and manually entered into the TAOC computer data base for display on air controller consoles. Again, this eliminates the necessity for one or more radio frequency changes by the aircrew.

• Upon arrival in the ASRT vicinity, the TAOC places the aircraft in a position at the appropriate heading, speed and altitude where the ASRT can acquire the aircraft with the AN/TPQ-10. Voice coordination between the TAOC and ASRT controllers assures an efficient handoff and eliminates the difficulties associated with ASRT target acquisition using only the fire control radar.

• During the air support mission, TAOC controllers monitor the airspace, assuring that hazards to flight safety are avoided.

• At the completion of the air strike, control is passed from the ASRT to the TAOC for RTB control. En route to home base, the aircrew passes BDA information to the TAOC controller who then passes that data to the TADC, thereby eliminating another frequency change by the aircrew. DASC-provided SAVAPLANE data again allows safe transit back to base.

• If refueling is required, the TAOC provides vectoring to the tanker and monitors the refueling mission, then resumes the RTB mission.

• As the aircraft nears the air base at Chu Lai, control passes to MATCU approach control/GCA controllers.

Apparently, aircrews found that this support was helpful, judging from the almost exponential increase in the use of the TAOC after only a short while. This was probably due to two factors: MACS-4’s promoting the system capabilities and aircrew realization that using the TAOC made things easier for them.

Air Situation Data Exchange in Southeast Asia

With all services participating in air operations in Southeast Asia in 1967, there was a requirement for the sharing of air situation information among air command and control agencies of the Marine Corps, Navy and Air Force. Data exchange between MACS-4 and Carrier Task Force (CTF) 77 operating in the Gulf of Tonkin (“YANKEE Station”) was accomplished over Link 11 through MACS-4s TDCC. Unfortunately, there was no in-country automated USAF capability. To overcome this shortfall, USAF surveillance operators from the USAF North Sector TACC (Callsign “PANAMA”), located on the western peak of Monkey Mountain, manned a surveillance console in MACS-4s TAOC and voice told track information to the USAF TACC from the TAOC and NTDS data bases displayed on the TAOC operator consoles. This was important in that, at the time, strikes were being made in North Viet Nam by aircraft based at I Corps and occasionally USN aircraft were required to divert to Da Nang because of weather in CTF 77s area or because of battle damage to the aircraft. MACS-4 had arrived “in country” with the capability to pass track data via an encrypted serial data link via a “Special Facilities Shelter”, built by the Naval Electronics Laboratory (NEL) in anticipation of a serial data exchange requirement through the TDCC. Eventually, the USAF received an Air Force system called Back-Up Intercept Control (BUIC) which provided serial digital data exchange. MACS-4 then acted as a “data hub” between USN and USAF, neither of whom could communicate directly with each other over data links.

As a result of difficulties experienced in Viet Nam in the sharing of air situation data, a “Southeast Asia Test Bed” was established in Southern California at System Development Corporation (SDC) in Santa Monica CA to further address this requirement and to help the services devise a solution to the problem. This Test Bed eventually was expanded, subsequently relocated to San Diego and eventually became the Joint Interface Test Facility (JITF), where multi-service digital data interface requirements were codified, resulting in the creation of standardized Tactical Digital Information Links (TADILs).

Requirement for Improvements to TAOC Capabilities

As planning for improvements in air defense weapons and the introduction of standardized digital data links progressed, it became apparent that changes would be required at the TAOC to incorporate the necessary weapon control and data exchange capabilities. Examples of the improvements in air defense weapons included the planned introduction of the F-14 into the MAW, changes to be made in the HAWK missile systems and the introduction into DoD of standardized digital data links – TADILS A, B, and C. Additionally, the potential deployment of the MACCS into the NATO aviation C3 structure required that the MACCS have the ability to interface with a NATO Control and Reporting Center (CRC) via NATO Link 1.

The U.S. Navy was developing the F-14 to increase their capability to protect the carrier task forces. The F-14 would provide expanded capabilities in airborne surveillance through the ability of its fire control system to acquire and track multiple air tracks, communicate this surveillance information to the NTDS via an expanded ground-air-ground data link and to engage multiple targets simultaneously by using PHOENIX missiles. Although this mission area was not applicable to the Marine Corps, USMC supported the Navy in the procurement battles and began to plan for the introduction of the F-14 into the Marine Corps. A test and evaluation squadron, VMF (AW)-XXX (does anyone know XXX?) based at MCAS, Beaufort, SC was designated to conduct the F-14 operational testing. A “Patrol Leader” concept was envisioned for the use of Marine F-14s in which a flight of aircraft, including one F-14 and multiple F-4s, would be used as a “package”, with the F-14 providing expanded airborne surveillance for the flight, the F-4s each attacking single targets sequentially, supplemented by the multiple air-to-air engagement capabilities of the F-14. Fortunately, for the unenthusiastic Marine Corps, before the actual procurement of USMC F-14s, the Navy released the Marine Corps from its commitment to support the Navy F-14 buy. Funds budgeted for USMC F-14s were reprogrammed to the purchase of additional F-4s or other aircraft.

Improvements to the HAWK surface to air missile system included the implementation of expanded data link capabilities for surveillance and weapon control. The major impact on the TAOC would be the replacement of the existing Missile Battery Data Link (MBDL) with Army Tactical Data Link 1 (ATDL-1) to be fielded as a part of the joint U.S. Army/USMC Improved HAWK (IHAWK) program. This would allow the SAM battery/battalion to provide the TAOC with expanded “gap filler” radar coverage, particularly for low fliers and tracks in high ground clutter areas. Additionally, the TAOC could provide SAM units with expanded early warning track data and better weapon cueing information.

A requirement for the use of TADILs for interservice and international digital data exchange required that the TAOC have the capability to transmit and receive data over the approved set of messages by surface-to-surface and surface-to-air links. Interfaces with “mobile” platforms, such as the U.S. Navy NTDS/ATDS, the U.S. Air Force Airborne Warning and Control System (AWACS) and with data link capable controlled aircraft would be via broadcast communication (TADIL A and TADIL C), while C2 systems which operated from fixed sites would use directional, point-to-point communications equipment (TADIL B, ATDL-1 and NATO Link 1).

In addition to these operationally oriented changes, several other changes were necessary to improve the ease of operation and maintenance of the TAOC/TDCC equipment.

Improved TAOC (ITAOC) Program

In the early 1970s effort began on an improvement program to define the necessary changes to the design of both the AN/TYQ-2 and AN/TYQ-3. The program was designated as the Improved TAOC (ITAOC) Program. Requirements were defined and contracts were to be awarded for the effort necessary to first define and then implement system design changes. To avoid potential bias in the definition phase by the AN/TYQ-2 and AN/TYQ-3 prime contractors, the definition contract included a hardware exclusion feature, which would exclude the definition contractor from participation in the implementation effort.

The overall design concept for ITAOC recognized that the TDCC, AN/TYQ-3, was now organic to each MACS and that the required standardized data exchange requirement could more easily be met by modifications to the general purpose computing capability of the TDCC as opposed to the less flexible computers in the AN/TYQ-2. For simplicity of design and to ensure that all required data would be available at each MACCS node, the Marine unique TACC-TAOC and TAOC-TAOC data links would be replaced by TADILs, although this was not strictly required for interservice links. System design changes would be necessary in the AN/TYQ-2 to accommodate expanded weapon control and display capabilities. Figure 4 shows the system architecture with ITAOC.

Proposed system design implementation documents were prepared and changes were made to one AN/TYQ-2 and one AN/TYQ-3, for test and evaluation at MCTSSA. The original “Q-2” prime contractor made changes to “Q-2” hardware and software, while the production contractor for the “Q-3” system made only the hardware changes to that equipment. The hardware modifications included the replacement of the large central computer with a family of minicomputers. Changes to both re-host the TDCC software and to expand the operational capabilities of the TDCC were designed, implemented and documented by the Tactical System Test Division (TSTD) of MCTSSA. This new MCTSSA generated software was designated Tactical Interface Message Exchange (TIMEX) because it was expected that it would be able to “take a licking and keep on ticking.” The MCTSSA effort was headed by then Major David H. Adams.

Following test and evaluation at MCTSSA, necessary changes were made to the system design and production contracts were awarded. Production systems were delivered to all FMF and training units on a “swap” basis to minimize the impact on operations. For example, a contact team consisting of USMC and ITAOC contractor personnel would proceed to a MACS concurrent with the receipt of the modified system. Installation and checkout of the new system was done by the contact team. The team would then conduct on-site, hands-on, operational and maintenance training for squadron personnel, addressing all changes to the system design. During system checkout and training on the ITAOC equipment, “normal” squadron operations continued using the unmodified system. When the Squadron Commander, with the advice and consent of the Marine head of the installation team, determined that the ITAOC system was acceptable, operations would move to the ITAOC. The “old” system would then be packed and shipped to the contractor for refurbishment, modification to ITAOC and reissue to another MACS. This process continued until all systems were updated to the ITAOC configuration.

TAOC-85 and the Tactical Air Operations Module (TAOM)

The MACCS was not the only system within the Marine Corps that would see a need for expanded automation. As early as the late 60s, it became apparent that the ground combat and combat service support elements of the MAGTF would have to become more responsive to increased operational needs. Consequently, a concept for addressing this requirement was instituted at HQMC. This concept, designated Marine Tactical Command and Control System (MTACCS), addressed the evolving needs of the entire MAGTF. A family of subsystems was envisioned to be implemented under the MTACCS concept. For example, the Marine Integrated Fire and Air Support System (MIFASS) was to be developed to combine the functions of the air support oriented DASC and the artillery oriented Fire Support Coordination Center (FSCC). Conceptually, these functions would be collocated in a new agency called the Fire and Air Support Center (FASC). The first C2 effort at MCTSSA was the creation of a MIFASS Test Bed to evaluate the viability of such a concept.

Other efforts under the MTACCS Concept included improvements for the MAGTF Ground Combat Element (GCE) under a program designated Tactical Combat Operations (TCO) and for the Aviation Combat Element (ACE) under a program designated Marine Air Command and Control System - 1975 (MACCS-75). MACCS-75 initially would have addressed improvements in all phases of aviation combat support. Soon it was realized that the scope of such an effort was probably too broad for efficient management and coordination, and it was renamed Tactical Air Operations Center-75 (TAOC-75). Because of the extended life of the TAOC/TDCC equipment under the ITAOC Program, the effort was redesignated again, this time as TAOC-85.

Under the TAOC-85 Program, a replacement for the existing ITAOC equipment’s was to be defined, developed, tested and produced. Advances in computer technologies and design techniques would be realized to increase the operational capabilities and reliability of the TAOC while significantly reducing the maintenance and lift requirements. The goal was to be achieved by an acquisition strategy, which would limit the Marine Corps investment in system development and use these savings for the procurement of production equipment. Consequently the effort was divided into three phases: a Contract Definition (CD) phase, a Full Scale Engineering Development (FSED) phase and a Production phase.

A system specification was prepared which defined the basic TAOC-85 system element: The Tactical Air Operations Module (TAOM) AN/TYQ-23. The TAOM equipment architecture was a radical change from that of the ITAOC system. See Figure 5. The MTDS/ITAOC system consisted of a “family” of equipment shelters, interconnected by cables, with each shelter addressing a specific system capability: Radar/IFF processing; central computing for track file maintenance and weapon control; operator displays; voice and data link communications. The ITAOC equipment architecture could be considered to consist of a set of “horizontal slices”, with each of the equipment shelters represented by a single “slice”. This architecture had several serious shortcomings related with TAOC operational versatility and transportability. To overcome these shortcomings, the TAOM was required to provide all TAOC capability in a single equipment shelter, with increased TAOC capacity achieved by interconnecting additional, identical TAOMs in a “building block” fashion. Thus, the TAOM equipment architecture can be viewed as consisting of a set of “vertical slices”, with all mission-essential hardware and software contained in each TAOM. A TAOC equipped with TAOMs could then provide a TAOC whose physical size and functional capacity are “tailored” to accommodate the size of the supported aviation combat element.

For the Contract Definition phase, competitive bids were solicited from industry. The baseline TAOM specification was provided to potential bidders. Since all features of the TAOM could not be precisely defined without a significant, and costly, technical evaluation, a list of additional, potential TAOM capabilities was also provided along with the baseline TAOM specification. This list was in the form of questions for study. For example, in a tactical air control system: Is an automated aircraft collision avoidance capability technically achievable and operationally desirable; do color operator displays provide a significant operational benefit, are they within the state of the art for tactical systems and are they cost-effective? Responders were to conduct the studies, basically at their expense, with operational guidance provided by Marines. They would then incorporate the appropriate system improvements into the baseline TAOM specification and submit a proposal for the production of a number of these TAOMs for operational test and evaluation in the FSED phase. Two CD contracts were awarded in mid-November, 1978, with responses due back in mid-May, 1979. After an evaluation of the two responses, a contract for the FSED phase was awarded in late-September, 1979, to produce five TAOMs.

After contract award, the U.S. Air Force joined the TAOC-85 program to field replacements for outdated semi-automated and manual air command and control equipment then in use at the USAF Control and Reporting Centers (CRC), Control and Reporting Posts (CRP) and Forward Air Control Posts (FACP). TAOMs, called Modular Control Equipment (MCE) by the Air Force, would automate all levels of USAF air C3 and allow them to streamline the air C3 architecture through the elimination of the CRP and FACP. The resultant USAF air command and control structure would consist of only CRCs which, like the TAOC, would be “tailored” to fit the needs of the supported aviation element. Because the late USAF entry into the program precluded the timely build of MCEs for test and evaluation, one USMC TAOM was redirected to the USAF and minor modifications to satisfy unique USAF requirements were installed into this MCE. The four TAOMs and one MCE were subsequently delivered to the USMC and USAF test sites.

As part of the TAOC-85 effort, it was necessary to assemble and train Marines to perform the test and evaluation of the TAOM. Initially, MACS-7, located at MCAS, Yuma, was designated as the test unit. This proved to be impractical, since MACS-7 was the only 3MAW air control squadron and the TAOM test and evaluation effort would conflict with 3MAW operational commitments. A decision was then made to reactivate MACS-1 at Camp Pendleton and designate it as the test unit, with the intent to deactivate it again at the conclusion of the test period. Events overrode this plan and MACS-1 remained in 3MAW as the second air control squadron. This proved to be most useful during Operation DESERT SHIELD, when there was an urgent requirement for a rapid deployment of a MACS to Southwest Asia. Fortunately, MACS-1 still “owned” prototype TAOMs. In August 1990, a cadre from MACS-1, along with two TAOMs, was airlifted to Saudi Arabia to establish a TAOC pending the arrival of an ITAOC-equipped MACS via sealift. (The accompanying photographs show one of the MACS-1 TAOMs). Upon the arrival in Southwest Asia of MACS-2 from Hawaii, the MACS-1 contingent and the two R&D TAOMs returned to Camp Pendleton.

A joint USMC/USAF production contract was awarded in 1987 and TAOM deliveries were made to all active and Reserve MACS as well as to MCCES at 29 Palms. Unlike the MTDS Program when unsheltered equipment was delivered to MCCES, the TAOMs at 29 Palms are identical to fielded systems and can be used as emergency replacements or augmentation, if required. A set of photographs show exterior and interior views of the TAOM.

Common Aviation Command and Control Systems (CAC2S)

The next logical step in the evolution of C3 equipment at the TAOC is to field common hardware for all C3 elements within the MACCS, with specific operational requirements of the several agencies satisfied by mission-unique software. This approach will reduce the cost of both the hardware and software used within the MACCS. Common, state-of-the art hardware would simplify maintenance and logistics support. Software common to the several agencies – operating systems, display, data link exchange, etc – would have to be generated only once, and software maintenance for these common items will be simpler and cheaper.

(Note to Editor: I just ran out of ammo – you’ll need to get someone smarter than I to pick it up here!!!!!)