- An Unclassified Summary Of PIRAZ (1968)
By Captain G.E. Lockee
Former Commanding Officer, U.S.S. Wainwright (DLG-28)
(Used with permission)
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.
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.
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.
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.
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.
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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
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
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.
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
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.
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.
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.
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.