PIRAZ is a new navy acronym for Positive Identification Radar Advisory Zone. A computerized guided missile ship performs this PIRAZ task. The most important mission of the PIRAZ ship is that of maintaining positive identification on a continuous basis of all aircraft within the radar advisory zone. The other missions performed by the PIRAZ ship support and complement the identification mission but none of these missions is more important. Radar is the primary aid used in making the detection and assisting in performing the identification process. The radar advisory zone of the Gulf of Tonkin consists of nearly 50,000 square miles of ocean area and the congested air space over it. This area is about the size of the states of Maine, New Hampshire, and Rhode Island combined.

Those who have watched the increased trend of attack carrier participation in operations in support of our national objectives since the early nineteen thirties, their employment in WW II, the Korean war, and now Viet Nam can appreciate the vital assistance provided to our attack carrier force by the PIRAZ ship.

After the U.S.S. Maddox incident in 1964, the decision was made to bomb targets in North Viet Nam. Yankee Station (the location from which the carriers operate) was moved closer to the North Viet Nam targets which meant that our carrier aircraft sortie rate could be significantly increased without increasing the attack carrier or strike aircraft inventory. The requirement for in-flight refueling could be significantly decreased. However, moving carriers closer to their targets made them more vulnerable to attack by the North Vietnamese. This brought about a greater need for the carrier force commander to keep himself informed (at all times) of the total air picture over the Gulf of Tonkin, and North Viet Nam. With larger numbers of US planes employed over the Gulf of Tonkin and over targets in North Viet Nam, the threat posed by the possible employment of North Viet Nam planes against our forces created a cause for grave concern. It therefore became vital that positive identity of all aircraft over the Gulf of Tonkin and over North Viet Nam, be positively established and constantly maintained.

The first logical step was to devise a system to maintain the identity and to keep track of all US planes in the area (radar advisory zone). Once such a positive identification was established on around the clock basis, the identity of all other aircraft became a simpler matter.

Keeping status boards updated and routinely handling several hundred airplanes in such a vital area immediately saturates the conventional Combat Information Center (CIC) with the conventional plastic status boards, talkers, plotters and grease pencils. Computerized automation was needed. Some direct readouts and fast automatic processing equipment was necessary. A radical reorganization of the conventional Combat Information Center had to take place. The realignment of the task of personnel was necessary. Not even our recently converted CLG's were capable of performing this vital PIRAZ task.

The call was sent out to the Naval Tactical Data System (NTDS) ships to perform this vital task. U.S.S. King (DLG 10) and U.S.S. Mahan (DLG 11) with NTDS, and their missile defense systems commenced performing the PIRAZ task in an exemplary manner.

The bigger ships such as the U.S.S. Long Beach (CGN 9) and U.S.S. Chicago (CG 11) with larger CIC's and more automatic data processing equipment have manned the PIRAZ station. Their greater capability has significantly expanded the PIRAZ functions and has provided even greater support and efficiency to seventh fleet operations in the Gulf of Tonkin against bombing targets in North Viet Nam. The navy's newest class of guided missile ships with our most sophisticated CIC's, NTDS, and weapons suits now perform the PIRAZ functions. The first of these new ships to man the PIRAZ station was U.S.S. Wainwright (DLG 28) who relieved U.S.S. Long Beach (CGN 9) in June of 1967. These modern anti-air warfare ships have found the environment of PIRAZ and their added capability ideally suited to perform the vital job at hand.

Following the U.S.S. Wainwright (DLG 28) to PIRAZ has been U.S.S. Fox (DLG 33), U.S.S. Belknap (DLG 26), and U.S.S. Biddle (DLG 34). These will be followed by others of the class.

The ship's Combat Information Center is still the heart and soul of PIRAZ. The new CIC is built in a series of modules. Each module houses a specific function; surface operations, air control, electronics warfare, sonar, underwater battery control, detection and tracking, weapons control, and display and decision. Inside 35-40 highly trained and motivated officers and men are on duty around the clock. The ship's commanding officer spends most of his time in this space rather than on the bridge. The ship is fought from CIC, not from the bridge as has been the custom of the past.

The PIRAZ ship's radars detect the targets. This activity is displayed on the NTDS consoles in the form of geometric symbols. The operators of the equipment determine the identity of the targets as friendly or hostile. This information is fed into the computer. The symbol on the console changes from a square (designation for an unknown) to a circle (friendly) or to a diamond (hostile). Most attack carriers on Yankee Station are also equipped with computers. The information is simultaneously displayed on the carrier's NTDS consoles.

With the preceding information fed into the computers. The operator can interrogate the computer by simply pushing a button on any of the consoles and receive instantaneously course, speed, altitude, range and bearing information on any friendly or hostile target. The computer provides recommendations such as the course and speed needed to steer a friendly fighter in order to intercept a specific target. It provides valuable threat information. If a plane needs refueling, the same controllers direct it to the nearest orbiting tanker aircraft. For friendly planes, the state of their fuel supply and number and types of weapons aboard can be ascertained. When a jet aircraft makes a turn, the computer symbol on the computer console duplicates the maneuver providing a "real time" picture and solution.

Naval Tactical Data Systems
The NTDS does away with the old problems of grease pencil bookkeeping, vertical plot tracking and display of enemy and friendly forces. It gives the commander the capability of understanding instantly the threats and the various alternatives to tactical problems or situations. The NTDS allows the ship's commander to sit back and to think of how he would react to the various attacks that might endanger his ship or the forces he is protecting, such as cruise missile attack, missile attack from aircraft, attack by ships of patrol boats.

The NTDS permits the PIRAZ ship to act as the task force's lone wolf, far from the task force being supported. NTDS installed in several ships is even more effective than in one ship only. In the task force concept, a data link constantly passes information between ships several hundred miles away. This provides the task force commander with information covering hundreds of miles.

It is not inconceivable that in the future task force tactical picture will be relayed back to the pentagon or to an area command headquarters by bouncing the data link signal off a relay satellite. This will provide the President, the pentagon or an area commander with the complete picture and immediate control from any part of the world should such control be needed. It is conceivable that in the white house and in the pentagon there will eventually be a computer complex with consoles which will present the status of all deployed forces in all theaters or area of the world.

Identification
The identification of unknown aircraft in the Gulf of Tonkin and over North Viet Nam is made easier by first keeping track of and accounting for the numerous friendly fixed track aircraft and sorties destined for targets in North Viet Nam. The process of keeping track of friendly aircraft usually starts 12-18 hours before the commencement of their specific flights on a particular day. Flight intentions are passed to the PIRAZ ship by the Air Force, Navy, and Marine Corps. From this information the PIRAZ ship prepares the necessary advisories for all those in her CIC team who must assist with the checking in, identifying, monitoring, and checking out process. Thus, by having such information instantly available and in a ready form, the identification, communications, bookkeeping, tracking, controlling and monitoring processes are significantly simplified. If the PIRAZ ship adequately plans for and keeps up with all of the friendly planes, the more difficult chore of detecting, tracking and providing necessary and adequate warning on the North Vietnamese MIG 17's and 21's, which may seriously hazard our own planes, is made much easier. If the MIG fighters do challenge our forces, the air intercept controllers manning the NTDS consoles direct navy fighters in for the kill.

Air Control
The PIRAZ ship has been frequently referred to as the seventh fleet's floating air control tower in the northern Gulf of Tonkin. The PIRAZ ship performs specific types of air control. This mission is a twenty-four hour a day chore. There are basically two kinds of air control conducted by the PIRAZ ship. One is Advisory Control and the other is Close Control. In the case of Advisory Control, the ship's air controller watches the airplane being controlled on the NTDS console and advises the pilot only as to a general area or general limits in which he must keep his aircraft. This type of control is normally used for barrier combat air patrol, area patrol aircraft, early warning aircraft, or tankers. In all of these examples, a block in space is usually satisfactory and the pilot keeps himself generally in this area by using TACAN or other means to fix his position. Should the air controller wish to adjust station this can be done by simply advising the pilot of the new dimensions of his new station. The air controller continuously watches his NTDS console to insure that the aircraft remains within the assigned boundaries.

Close Control or Positive Control is an entirely different matter. Positive Control requires that the air controller provide specific altitudes, courses, and speeds to the pilot he is controlling. Positive Control is necessary in order to vector his plane to a specific point in space for a specific purpose, such as identification of an unknown target or interception of a hostile contact. Here again, the NTDS system provides the computerized recommendations required to make the intercept.

With NTDS employment and with the more sophisticated airborne weapons the fighter pilot is not required to visually see his target. Instead, he fires by radar. Radar is used to guide the missile to it's target. In this type of modern air warfare the air intercept controller on the PIRAZ ship many miles away can assist the pilots of our interceptors in downing enemy planes. Today's jet fighter pilots need a detailed understanding of highly complex and sophisticated electronics systems. A new realization quickly sinks home that the computer introduces the cold, impersonal ruthlessness of "push button" warfare.

Provide Assistance
On a normal day the PIRAZ ship monitors the sorties of the Navy, Air Force, and Marine Corp strikes in North Viet Nam. During a heavy strike operation, over 150 planes may be in the air at one time.

Providing many types of assistance to many air craft - Navy - Air Force - Marine Corps - is a never-ending PIRAZ task. The nature of assistance includes communications, vectors to tankers for any aircraft in a low fuel state, relaying many types of operational or combat information providing continuous navigation and SAR information. The amount and type of information provided are dependent upon the overall capability and quality of the performance of the PIRAZ ship. This means, if the PIRAZ ship can answer the questions or provide the routine information requested, the probability of being requested to provide additional assistance increases.
The PIRAZ ship provides much valuable and timely information to strike aircraft by keeping it's information depository updated and readily available to respond to strike aircraft demands and requirements in a frequently changing environment. Here again the computer's ability to be brought into play is the key to providing an abundance of continuous assistance to all friendly forces in the Gulf of Tonkin. The passing of SAR information is another important type of advisory service.

In addition to being fitted with the latest in computerized equipment for maintaining a real time picture of all air contacts, the PIRAZ is also fitted with the latest in surface and subsurface detection equipment which gives it superior depth in three dimensional warfare.

Hostile Aircraft Warnings
Protection of friendly aircraft from enemy aircraft attack is an important PIRAZ mission. The PIRAZ ship with her radars and NTDS computers maintain an accurate plot of all aircraft including friendlies, unidentified and hostiles. When unidentified or hostile aircraft pose a threat to friendly aircraft, the PIRAZ ship is usually in the best position and is frequently the first to issue a warning of the presence of hostile aircraft. There are some few cases in which some hostile aircraft may not be held on the PIRAZ ship radar ; however, the PIRAZ ship would have the information plotted from other radars. In such cases the PIRAZ ship would relay these warnings to those friendlies and to other commands who would have a need of such knowledge.

Border Warnings
One look at the map of southeast Asia and the gulf of Tonkin area show the sensitiveness and closeness of the Communist Chinese border to the north, and the close proximity of the Chinese island of Hainan to the east. With US. jet fighters streaking to within less than a minute of the Chinese border, it is the PIRAZ ship that helps keep them from crossing the line and perhaps triggering an international incident. The border warning issued to these aircraft by the PIRAZ guided missile ship steaming in the Gulf of Tonkin prevents such an incident.

The problem of assisting friendly aircraft from violating these forbidden borders is a never ending task. This mission becomes extremely delicate when sites near these borders are to be targets for a particular strike. The PIRAZ ship is called on to provide for preciseness in this task. This is a preciseness in which only superior radars and the NTDS can provide. When friendlies approach the buffer or border zone - PIRAZ issues border warnings.

The ability to communicate this warning in a timely manner is important and is relatively simpler task because of the superior communications capability of the PIRAZ ship. For the few instances where contact may not be held by the PIRAZ ship, the PIRAZ ship relays this warning to insure that friendly aircraft do not cross the border into forbidden country.

Identify Hostiles And Destroy
The PIRAZ ship is a guided missile ship. When planes are identified as hostile and pose a threat to friendly forces, the PIRAZ ships' missile systems are in constant readiness to be used to defend these friendly forces in the same manner as our target Combat Air Patrol (CAP) defend their strike aircraft. Here again emphasis is placed on the positive identification ability of the PIRAZ ship. This is not the time to have doubt about friendly or hostile identity of aircraft in the radar advisory zone.
In addition to using her missile systems in defense of friendly forces, the PIRAZ ship employs her other defensive surface anti-submarine missiles should they be needed.

Barrier Combat Air Patrol
The PIRAZ ship is assigned the primary mission of stationing and controlling the Barrier Combat Air Patrol. This patrol may be an advisory or positive type of control. During routine operations, advisory control on a prearranged barrier is all that is required. However, when friendly forces are threatened, positive control is exercised and the Combat Air Patrol is repositioned in altitude and vectored on proper course at proper speed to the best intercept position in order to protect friendly forces. This patrol may also be used to determine the positive identity of surface craft in case there is any doubt.

Flight Following
Maintaining communications and the position of each strike from each Yankee Station carrier is another important and interesting PIRAZ task. This task is done by a PIRAZ ship air controller and for this specific function is called a "flight follower". A flight follower maintains radio and radar contact on his NTDS console with the planes from each carrier (one flight follower per CVA or Air Force strike).
By concentrating on a single carriers' strike aircraft, the flight follower is able to assist more readily with the many specific details surrounding the flight.

The NTDS console allows the flight follower to keep himself informed as to the specific details of the strike aircraft from the time the strike is launched, checked into PIRAZ, in flight refueled (if necessary), arrives at the coast in point, maintains contact over target, returns at coast out point, in flight refueled (if necessary), checked out of PIRAZ and returns to the mother carrier. The flight follower in effect rides with the strike leader to the target and returns while providing much of the information already mentioned above, as well as that of providing surface to air missile and MIG warnings.

The flight follower can in most cases provide the exact position of damaged or shotdown aircraft. Other than for routine establishment of communications, the role of the flight follower is primarily passive until an emergency develops or until active assistance need be rendered. The flight follower may pass mayday (emergency information) posits to the SAR commander, vector a plane to a tanker plane over the gulf, or vector still another plane to a geographic reference point along the coast line. This turns out to be an extremely important task and its importance increases in the case of SAR activity.

Search And Rescue Mission Platforms
All PIRAZ ships are equipped for helicopter landings. The helicopter platforms provided a base for helicopter operations when such is needed for Search And Rescue missions (SAR). These ships also are equipped to perform minor maintenance and upkeep for the SH3A (affectionately referred to as "big mothers") of UH2 helicopters. The PIRAZ ships also provide a fueling station for both on deck or in flight refueling to Navy and Air Force helicopters. The Air Force SAR helicopters are affectionately called "jolly greens".

A permanent helicopter landing team made up of damage controlmen, fueling personnel, chockmen for securing once the helicopter lands, and a landing signal officer is provided in the ships organization. The SAR helos are airborne during major air strike activity and rest on the flight deck during the remainder of the daylight hours. It is not unusual for a PIRAZ ship to chalk up over 400 helo landings during a single deployment.

Prosecute Or Assist In Search And Rescue Missions
As a result of flight following strike aircraft (Navy, Air Force and Marine Corps) the PIRAZ ship is always in a position to render immediate assistance in SAR operations. The specific SAR functions performed by the PIRAZ ship are those actually directed by the SAR commander depending upon the circumstances at the time.

Relay Of Surface To Air Missile Warnings
The PIRAZ ship by virtue of its electronics counter measures capability, its location in the Gulf of Tonkin, and its position in the communications network with other early warning systems, transmits or relays warnings of potential Surface to Air (SAM) threats to our aircraft when such SAM information is detected.

Secondary Missions
Other missions are to broadcast computer track information to non computer ships and stations, and to provide surface and subsurface surveillance information to the surface and subsurface surveillance commander maintaining real time data links with the other Naval Tactical Data system aircraft in the Gulf of Tonkin are routinely performed by the piraz ship. Many of the aircraft carriers in the Gulf of Tonkin also employ the NTDS and are able to benefit from the valuable computer displays of the PIRAZ ship.

Briefly stated, the PIRAZ functions entail all the aspects of antiair warfare, air traffic control, airspace surveillance, positive identification, and maintaining an around the clock up to date status of all air activity in the Gulf of Tonkin. It requires modern long range radar and identification equipment which is maintained in a high state of readiness. It requires a unique type of CIC team who must frequently stand port and starboard watches for long and indefinite periods of time (up to 40 days) in order to accomplish the many complex PIRAZ tasks. Accomplishment of the PIRAZ tasks stresses a ship, its equipment, and its personnel like no other cruiser-destroyer assignment of the past.

PIRAZ Is A Most Challenging Undertaking.