United States Navy Formalizes the 'Positive Identification Radar Advisory Zone' Known as PIRAZ

PIRAZ is a United States Navy acronym for Positive Identification RADAR Advisory Zone.

The zone is defined by the air search RADAR coverage of a ship patrolling a designated PIRAZ station. The PIRAZ ship requires a Naval Tactical Data System radio-linked computer installation to effectively identify and track all aircraft anticipated to utilize zone airspace during combat.

The concept originated in the summer of 1966 as Yankee station was established for United States Task Force 77 aircraft carriers launching strikes against North Vietnam fixed patrol station within range of land-based aircraft made the stationed aircraft carriers vulnerable to attack. A PIRAZ station was established in the westernmost portion of the Gulf of Tonkin where air search RADAR coverage might extend over North Vietnam and the air-strike routes from Yankee station. This PIRAZ station radio call sign was "Red Crown." The first PIRAZ ships were USS King (DLG-10), USS Mahan (DLG-11), USS Long Beach (CGN-9), and USS Chicago (CG-11). Belknap class cruisers began rotating into PIRAZ station assignments in 1967; and USS Wainwright (CG-28), assisted in the Son Tay Raid on 21 November 1970.
USS Agerholm (DD-826) was typical of the ships providing torpedo boat destroyer "shotgun" escort for the Gulf of Tonkin PIRAZ station.

PIRAZ cruisers carried long-range RIM-2 Terrier or RIM-8 Talos surface-to-air missiles to defend their stations. Each PIRAZ cruiser was accompanied on station by a "shotgun" torpedo boat destroyer with quick-firing guns to defend the PIRAZ cruiser from torpedo boat attack. PIRAZ cruisers provided protective RADAR surveillance of the remotely piloted vehicles performing aerial photo reconnaissance of North Vietnam.

As the Gulf of Tonkin PIRAZ station routine developed, a PIRAZ cruiser would typically remain on station for approximately 30 days before being relieved by another cruiser. During the 30-day relief period, the cruiser would usually travel to a liberty port in Hong Kong or Japan and then to the U. S. Naval Base Subic Bay for minor repairs and missile firing exercises before returning to the PIRAZ station. The cruiser would typically return to a United States home port for approximately six months after three PIRAZ station assignments with two intervening relief periods.

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.