View source for AN/TPQ-10 Radar Course Directing Central

{{short description|Ground based bombing system used by US Marines}}

{{Infobox Radar 
|name        = AN/TPQ-10
|image       = ANTPQ-10 Radar at MASS-3.jpg
|caption     = 
|country     = United States 
|introdate   = 1960/61
|number      = 
|type        = 
|frequency   = 
|range       = 
|altitude    =
|diameter    = 
|azimuth     = 360°
|elevation   = 
|precision   = 
|power       = 250 kw
}}

The [[General Electric]] '''AN/TPQ-1O Course Directing Central''' was a light-weight, two-unit, helicopter transportable, ground based bombing system developed for use by the [[United States Marine Corps]] to provide highly accurate, day/night all weather [[close air support]].  This self-contained system was designed to guide an aircraft, equipped with the proper control equipment, to a release point for accurate all-weather delivery of ordnance and supplies to a preselected target.   The AN/TPQ-10 and its operators were known as an ‘’Air Support Radar Team’’ (ASRT) and were employed by the [[List of United States Marine Corps air support squadrons|Marine Air Support Squadrons]] within the [[Aviation Combat Element]]. 
 
The system was originally fielded in the early 1960s to replace the MPQ-14 Course Directing Central radar which was first utilized during the [[Korean War]].  The AN/TPQ-10 saw extensive use during the [[Vietnam War]] supporting Marine Forces in the [[I Corps (South Vietnam)|I Corps Tactical Zone]] from 1965 through 1971, most famously to great effect during the [[Battle of Khe Sanh]] in early 1968.<ref>[https://www.marines.mil/Portals/1/Publications/Close%20Air%20Support%20and%20the%20Battle%20for%20Khe%20Sanh%20%20PCN%2010600090000_2.pdf Close Air Support and the Battle for Khe Sanh Pgs 115-119]</ref>  It remained a mainstay of Marine Corps close air support tactics until it was phased out of the inventory in the early 1990s after the [[Gulf War]].   Improved [[avionics]] in military aircraft and the emerging use of [[Global Positioning System|satellite based navigation systems]] had quickly made the AN/TPQ-10 redundant and obsolete.

==Development & Production of Radar Controlled Bombing Equipment==
The Marine Corps experimented with radar controlled bombing as early as December 1944 when an [[SCR-584 radar]] from the [[8th Antiaircraft Artillery Battalion]] on [[Kauai]] was utilized to direct simulated bombing missions with [[Curtiss SB2C Helldiver|SB2C]] and [[Douglas SBD Dauntless|SBD]] dive bombers.  Early results from these tests were positive.<ref name="1stProvAAAGrpDec44">{{cite report |author=<!--Not stated--> |date=January 3, 1945|title=War Diary, 1 - 31 December 1944|url=https://commons.wikimedia.org/wiki/File:1st_Prov_AAA_Group_-_19441201-19441231_-_War_Diary.pdf|publisher=First Provisional Antiaircraft Artillery Group|page=3}}</ref>  The Marine Corps tried again in combat in May 1945 when poor weather during the [[Battle of Okinawa]] led Marines to attempt new methods of striking targets from the air.  [[Direct Air Support Center#World War II|Landing Force Air Support Control Unit III]] (LFASCU III), working in support of the [[Tenth United States Army|United States 10th Army]] attempted to direct bombing runs in the vicinity of [[Shuri Castle]] utilizing an SCR-584 that was co-located with them for the original purpose of directing night fighters.  These early attempts proved unsuccessful however the seeds of ground based radar control of close air support were planted.

In November 1945, the [[Commandant of the United States Marine Corps|Commandant of the Marine Corps]] directed the Commanding General of the [[9th Marine Aircraft Wing]] to evaluate the [[AN/MPQ-2|AN/MPQ Close Cooperation Control Unit]] for use in close air support operations.  Testing was conducted by [[Marine Air Control Group 28|Marine Air Control Group 1]] (MACG-1) under the command of [[Robert O. Bisson|Colonel Robert o. Bisson]] from 12 April – 6 September 1946.  For this testing they utilized an AN/MPQ-2 radar borrowed from the [[United States Army Air Corps]] and a [[Vought F4U Corsair|F4U Corsair]] fitted with an AN/APN-19 radar beacon.<ref>[https://commons.wikimedia.org/wiki/File:MACG-1_-_19460401-19460630_-_History_-_1_Apr-30_Jun_46.pdf Marine Air Warning Group 1 - History - 19460401-19460630]</ref><ref>[https://commons.wikimedia.org/wiki/File:MACG-1_-_19460701-19460930_-_History.pdf Marine Air Warning Group 1 - History - 19460701-19460930]</ref>  Testing of this radar for close air support continued at MACG-1 through 1949.

While testing continued on the east coast, Major Marion Dalby, led a team of 14 Marines comprising the Marine Corps Liaison Unit of the [[Pacific Missile Test Center|Naval Air Missile Test Center]] at [[Naval Air Station Point Mugu]], [[California]] were tasked to utilize an SCR-584 radar to direct [[Republic-Ford JB-2|KGW-1 Loon Missiles]] being fired from submarines. They were testing emerging amphibious concepts such as command guiding submarine fired missiles against mapped beach fortifications in support of  Marines after they had come ashore during an [[amphibious warfare|amphibious assault]]. Because Loon Missiles were so hard to come by during training, the Marines devised a plan to where more easily available aircraft would replicate the missile's controlled phase of flight and a bomb carried on the plane would replicate the missile's free fall stage of flight.  To do this, they designed a small computer that could be carried ashore from a ship and a device that allowed the automatic pilot in an F4U Corsair to accept radio commands from the ground based control system as if it were coming from the plane itself.  The computer system told the pilot where to fly and when to drop the bomb.  It was during this testing that Major Dalby and his Marines realized that the technology that they developed would have a much more practical application guiding close air support aircraft onto targets.  Follow on testing and development of the new computer system in concert with naval engineers at NAS Point Magu and switching the radar to an SCR-784 (amphibious, trailer-mounted version of the SCR-584) had it ready for operational testing.

In April 1950, Dalby and his team travelled to [[Marine Corps Base Camp Pendleton]], California to put on a demonstration of their new radar directed bombing device for senior Marine Corps leadership.  The tests were very successful and among those that witnessed the first demonstration were then Colonel [[Victor H. Krulak|Victor H. “Brute” Krulak]].  Years later, Krulak devoted an entire chapter in his book ‘’First to Fight: An Inside View of the U.S. Marine Corps’’ to the development of this radar by Dalby and his team.  This new system would be designated as the [[Reeves AN/TPQ-2 Close Air Support System|AN\TPQ-2 Close Air Support System]] and would be ready for deployment to Korea in July 1951.

The AN/MPQ-14 controlled close air support sorties in Korea from August 1951 until the cessation of hostilities in July 1953.  The 1st Marine Air Support Radar Team (1st MASRT), nicknamed "Devastate Charlie", was attached to [[Marine Air Support Squadron 2|Marine Tactical Air Control Squadron 2]] (MTACS-2) and operated in support of the [[1st Marine Division (United States)|1st Marine Division]].

In light of the advancement in the development of equipment, the Marine Corps wanted to improve the accuracy and increase the mobility of the AN/MPQ-14A.  A contract was signed with [[General Electric]] to develop a system similar in function to the AN/MPQ-14A but having longer range, multiple target capability, greater versatility, better transportability, and weighing less.<ref>[https://commons.wikimedia.org/wiki/File:AN-TPQ-10_-_19590911_-_Evaluation_of_AN-TPQ-10(XN-2)_RCDC_Interim_Report.pdf Evaluation of AN/TPQ-10 (XN-2) Radar Course Directing Central (Interim Report) – 11 September 1959]</ref>   The AN/TPQ-10 was the system developed under this contract.  The AN/TPQ-10 was produced by General Electric's Heavy Military Electronics Department in [[Syracuse, New York]].

==Operational history==
The first operational deployment of the ASRT was in October 1962 when elements of [[Marine Air Support Squadron 1]] were deployed to the [[Guantanamo Bay Naval Base]] in [[Cuba]] as part of the [[Marine Expeditionary Brigade]] formed during the [[Cuban Missile Crisis]].  The ASRT was sent to [[South Vietnam]] in April 1965 when [[Marine Air Support Squadron 2]] deployed from [[Okinawa Island|Okinawa]], [[Japan]] to support the [[9th Marine Expeditionary Brigade (United States)|9th Marine Expeditionary Brigade]] after they landed near [[Da Nang]].  The first AN/TPQ-10 was set-up 250 feet off the runway at [[Da Nang Air Base]] and conducted its first mission on the evening of 31 April 1965 when it provided direction for a C-130 on a flare dispensing mission.  At 2150L on 10 May 1965, CWO2 James Harold Davis controlled a division of [[McDonnell Douglas F-4 Phantom II|F-4 Phantoms]] against targets southwest of Da Nang known as [[Happy Valley, Vietnam|Happy Valley]].  These were the first ever operational course directed bombing runs in a combat zone utilizing the AN/TPQ-10.<ref>[https://commons.wikimedia.org/wiki/File:4_-_April_1965.pdf MASS-2 Command Diary for April 1965]</ref>

During the [[Battle of Khe Sanh]] in 1968, ASRT B from MASS-2 controlled more than 5,000 air strikes.  The ASRT was critical to the successful defense of the base.

The AN/TPQ-10 was utilized for additional mission sets as the Vietnam War progressed.  They provided course direction for aircraft that were resupplying forward positions via [[Airdrop|aerial resupply]].  In emergency situations they also provided [[Ground-controlled approach]] services at airfields when [[Air Traffic Control|Air Traffic Control's]] [[precision approach radar]]s were not available.

==See also==
*[[AN/MPQ-2]]
*[[Reeves AN/TPQ-2 Close Air Support System]]
*[[Reeves AN/MSQ-77 Bomb Directing Central]]
*[[List of military electronics of the United States]]

== Citations ==
{{reflist}}

== External links ==
* [https://www.youtube.com/watch?v=7Iea4X3Xmk8 Video showing MASS-2 AN/TPQ-10 operations during the Vietnam War]

[[Category:Military computer systems of the U.S. Department of Defense]]
[[Category:Cold War military radars of the United States]]
[[Category:General Electric radars]]
[[Category:Ground radars]]
[[Category:Military radars of the United States Marine Corps|TPQ10]]
[[Category:Military equipment introduced in the 1960s]]
[[Category:Military electronics of the United States]]