The Grumman A-6 Intruder was an American, twin jet-engine, mid-wing all-weather attack aircraft built by Grumman Aerospace. In service with the United States Navy and Marine Corps between 1963 and 1997, the Intruder was designed as an all-weather medium attack aircraft to replace the piston-engined Douglas A-1 Skyraider. As the A-6E was slated for retirement, its precision strike mission was taken over by the Grumman F-14 Tomcat equipped with a LANTIRN pod. From the A-6, a specialized electronic warfare derivative, the EA-6, was developed.
Following the good showing of the propeller-driven AD-6/7 Skyraider in the Korean War, the United States Navy issued preliminary requirements in 1955 for an all-weather carrier-based attack aircraft. The U.S. Navy published an operational requirement document for it in October 1956. It released a request for proposals (RFP) in February 1957.
The first prototype YA2F-1, lacking radar and the navigational and attack avionics, made the Intruder's first flight on 19 April 1960,