The Northrop Grumman (formerly Grumman) EA-6B Prowler is a twin-engine, four-seat, mid-wing electronic warfare aircraft derived from the A-6 Intruder airframe.The EA-6A was the initial electronic warfare version of the A-6 used by the United States Marine Corps in the 1960s.he Prowler first flew on 25 May 1968, and it entered service on aircraft carriers in July 1971. Three prototype EA-6Bs were converted from A-6As, and five EA-6Bs were developmental airplanes. A total of 170 EA-6B production aircraft were manufactured from 1966 through 1991.