Editing Grumman A-6 Intruder (section)

===Further development===
During February 1963, the A-6 was introduced to service with the US Navy; at this point, the type was, according to Gunston and Gilchrist, "the first genuinely all-weather attack bomber in history".<ref name = "bomber 210">Gunston and Gilchrist 1993, p. 210.</ref> However, early operating experiences found the aircraft to be imposing very high maintenance demands, particularly in the Asian theatre of operations, and serviceability figures were also low. In response, the Naval Avionics Lab launched a substantial and lengthy program to improve both the reliability and performance of the A-6's avionics suite.<ref name = "bomber 210"/> The successful performance of the A-6 in operations following these improvements ended proposals to produce follow-on models that featured downgraded avionics.<ref name="Andrews">{{cite magazine |last=Andrews |first=Hal |title=Life of the Intruder |magazine=Naval Aviation News |volume=79 |issue=6 |date=September–October 1997 |pages=8–16}}</ref>

Various specialized variants of the A-6 were developed, often in response to urgent military requirements raised during the [[Vietnam War]].<ref name = "bomber 21011"/> The ''A-6C'', a dedicated interdictor, was one such model, as was the ''KA-6D'', a [[Aerial refueling#Buddy store|buddy store]]-equipped aerial refueling tanker. Perhaps the most complex variant was the [[EA-6B Prowler]], a specialized [[electronic warfare]] derivative. The last variant to be produced was the ''A-6E'', first introduced in 1972; it features extensive avionics improvements, including the new [[AN/APG-76#AN/APQ-148|APQ-148]] multimode radar, along with minor airframe refinements.<ref name = "bomber 21011">Gunston and Gilchrist 1993, pp. 210-211.</ref> The last A-6E was delivered in 1992.<ref>{{cite web |url = https://www.flightglobal.com/northrop-grumman/4209.article |title = Northrop Grumman |publisher = Flight International |date = 23 October 1996}}</ref>

In the early 1980s, the Navy anticipated that an Advanced Carrier-Borne Multirole Fighter (VFMX) would eventually be the long term high-end replacement for both the F-14 and A-6, although this program was short-lived and was succeeded by separate efforts for fleet air defense and deep strike/attack; the latter became the Advanced Tactical Aircraft (ATA) program resulting in the development of the [[McDonnell Douglas A-12 Avenger II]].<ref>{{cite report |last1=Parker Jr. |first1=James F |last2=Christensen |first2=Diane G. |last3=Mutimer |first3=George R. |url=https://apps.dtic.mil/sti/tr/pdf/ADA177469.pdf |title=Life Support and Protection Requirements for the Head/Neck Region of Navy Aircrewmen |date=December 1986 |publisher=Office of Naval Research |page=7}}</ref><ref>{{cite book |last=Larrimer |first=Bruce I. |title=Think Obliquely: Robert T. Jones, the Oblique Wing, NASA's AD-1 Demonstrator, and Its Legacy |url=https://www.nasa.gov/wp-content/uploads/2015/04/ThinkingObliquely-ebook.pdf |publisher=National Aeronautics and Space Administration (NASA) |location= |year=2013 |isbn=978-1-62683-005-9 |page=144}}</ref> Meanwhile, a further model, designated ''A-6F'', was being planned. Intended to feature the [[General Electric F404]] [[turbofan]] engine, as well as various avionics and airframe improvements, this variant was cancelled under the presumption that the A-12 would be entering production before long.<ref name = "bomber 211">Gunston and Gilchrist 1993, p. 211.</ref><ref name = "flyint 2011">{{cite web |url = https://www.flightglobal.com/us-naval-aviation-back-on-the-rise/99159.article |title = US naval aviation back on the rise |publisher = Flight International |first = Stephen |last = Trimble |date = 4 April 2011}}</ref> Instead, a life-extension program involving the re-winging of existing A-6E aircraft was undertaken; initially a metal wing had been used before a [[graphite]]-[[epoxy]] [[composite material|composite]] wing was developed during the late 1980s.<ref name = "bomber 21112">Gunston and Gilchrist 1993, pp. 211-212.</ref> Other improvements were introduced to the fleet around this time, including [[GPS]] receivers, new computers and radar sets, more efficient J-52-409 engines, as well as increased compatibility with various additional missiles.<ref name = "bomber 212">Gunston and Gilchrist 1993, p. 212.</ref>