View source for AN/AWG-9

{{short description|X band pulse-Doppler military aircraft radar}}
{{more citations needed|date=March 2019}}
[[Image:F-14 Radar TID.jpg|thumb|300px|Tactical information display (TID) of radar data in the rear seat of an F-14A.]]
[[File:F-14 Tomcat radar USSHM.JPG|thumb|The radar antenna of an AN/AWG-9 on display in the [[USS Hornet Museum]] ]]

The '''AN/AWG-9''' and '''AN/APG-71''' radars are all-weather, multi-mode [[X band]] [[pulse-Doppler radar]] systems used in the [[F-14 Tomcat]], and also tested on [[Douglas A-3 Skywarrior|TA-3B]].<ref>[https://babel.hathitrust.org/cgi/pt?id=mdp.39015016793294;view=1up;seq=629 Department of Defense appropriations for 1976], pt.2, p. 621.</ref> It is a long-range air-to-air system capable of guiding several [[AIM-54 Phoenix]] or [[AIM-120 AMRAAM]] missiles simultaneously, using its [[track while scan]] mode. The AWG-9 utilizes an [[analog computer]] while the APG-71 is an upgraded variant utilizing a [[digital computer]]. Both the AWG-9 and APG-71 were designed and manufactured by [[Hughes Aircraft Company]]'s Radar Systems Group in [[Los Angeles]]; contractor support was later assumed by [[Raytheon]]. The AWG-9 was originally created for the canceled Navy [[F-111B]] program.<ref name="Sweetmanp622">Sweetman 1987, p. 622.</ref>

The AN/AWG-9 offers multiple air-to-air modes: long-range [[continuous-wave radar]] velocity search, range-while-search at shorter ranges, and an airborne track-while-scan mode with the ability to track up to 24 airborne targets, display 18 of them on the cockpit displays, and launch against 6 of them at the same time. This function was originally designed to allow the Tomcat to shoot down formations of bombers at long range.

==AN/AWG-9==
The AWG-9 was the result of a series of [[United States Navy]] programs to build what was known as a "fleet-defense fighter": an aircraft armed with extremely long-range radars and missiles that would be able to engage formations of enemy aircraft well-away from [[aircraft carrier]]s. Their first attempt was the [[F6D Missileer]], which combined [[Westinghouse Electronic Systems|Westinghouse]]'s [[AN/APQ-81]] pulse doppler radar with the [[Bendix Aviation|Bendix]] [[AAM-N-10 Eagle]] missile. The Missileer was a relatively simple aircraft, and when planners expressed doubts about its ability to survive after firing its missiles, the Missileer was canceled and the Navy started looking for higher-performance alternatives.

At the same time, the [[U.S. Air Force]] had been working on a similar long-range interceptor project of their own, the [[XF-108 Rapier]]. The Rapier had much better performance than the Missileer, although its [[AIM-47 Falcon]] and [[AN/ASG-18]] radar, both from Hughes, were somewhat less advanced than their Navy counterparts. The entire system was also very expensive, and the Rapier was canceled, replaced by the hopefully less-expensive [[Lockheed YF-12]] adapted from the [[Lockheed A-12]] spy plane. This project was also canceled as the strategic threat moved from bombers to [[ICBM]]s.

The same was not true for the Navy, where the threat remained manned aircraft and early [[anti-ship missile]]s. Hughes suggested that the AN/ASG-18 and AIM-47 could be adapted for the Navy in slightly modified form, adding additional tracking capability while reducing the size of the radar antenna to a size more suitable for carrier aircraft. The result was the AN/AWG-9 radar and Phoenix missile.

All that was needed was a suitable airframe, which led to the Navy's involvement in the [[F-111B]] program. Although the radar and missile systems started to mature (after the better part of a decade at this point) the F-111B proved to be considerably overweight and had marginal performance, especially in engine-out situations. At the same time, real-world combat over [[Vietnam]] was proving that the idea of the all-missile fighter was simply not viable, and any fighter design would have to be able to [[dogfight]] with guns, which the F-111 was simply not suited to. This should not be surprising given the F-111's genesis as a [[tactical bomber]] and [[interdictor]].

After many years in development and arguing with Congress, the Navy finally started development of a new aircraft specifically tailored to their needs. The new aircraft emerged as the F-14, armed with the same AWG-9/AIM-54 outfit originally intended for the F-111B. On the F-14, the AWG-9 is capable, and its doppler system allows it to have look-down, shoot-down capabilities.<ref>Modern Marvels: F-14 History Channel DVD</ref>

Hughes delivered enough AWG-9 systems and spares to equip approximately 600 F-14A/B aircraft for the Navy, and an additional 80 aircraft for the [[Imperial Iranian Air Force|Iranian Air Force]]. All of the Navy systems have been retired; some of Iranian systems are still in service.

==AN/APG-71==
The APG-71 was a 1980s upgrade of the AWG-9 for use on the [[F-14D Tomcat]]. It incorporates technology and common modules developed for the [[APG-63 and APG-70 radars|APG-70]] radar used in the [[F-15E Strike Eagle]], providing significant improvements in (digital) processing speed, mode flexibility, clutter rejection, and detection range. The system features a low-sidelobe antenna, a sidelobe-blanking guard channel, and monopulse angle tracking; all of which are intended to make the radar less vulnerable to jamming.

The system itself is capable of a {{convert|460|mi|adj=on}} range, but the antenna design limits this to only {{convert|230|mi}}. Use of [[Data link|datalinked]] radar data allows two or more F-14Ds to operate the system at its maximum range.

Hughes delivered enough APG-71 radars and spares to equip all 55 F-14Ds produced or converted before the F-14D program was scaled back as a cost-cutting measure and eventually canceled. The F-14 was officially retired from United States Navy service on September 22, 2006, with the last flight occurring October 4, 2006.

==See also==
{{Portal|Electronics|Aviation}}
*[[Index of aviation articles]]
*[[List of radars]]
*[[List of military electronics of the United States]]
*[[Joint Electronics Type Designation System]]

==References==

===Citation===
{{Reflist}}

===Bibliography===
* Sweetman, Bill and Bonds, Ray. ''The Great Book of Modern Warplanes''. New York, New York: Crown Publishers, 1987. {{ISBN|0-517-63367-1}}

==External links==
* [http://www.fas.org/man/dod-101/navy/docs/fun/part06.htm Track-While-Scan Concepts]

{{Raytheon|state=collapsed}}


[[Category:Aircraft radars]]
[[Category:Raytheon Company products]]
[[Category:Equipment of the United States Navy]]
[[Category:Military electronics of the United States]]
[[Category:Military radars of the United States]]
[[Category:Military equipment introduced in the 1970s]]
[[Category:Radars of the United States Air Force]]