Authored By Dan Alex (Updated: 4/5/2016):
Work revealed a flyable prototype which first took to the skies on April 19th, 1960. The prototype YA2F-1 would largely resemble the finalized A-6 Intruder known today but featured a unique quality with its swiveling jet pipe nozzles which were to allow for short runway take-offs when pointing downwards. The rest of the aircraft constituted tear drop-shaped fuselage with bulbous frontal section and severely tapering aft section, high-mounted and rearward-swept monoplane wing assemblies, and a wide two-man, side-by-side cockpit arrangement (pilot at left with the bombardier at right). Indeed the aircraft took on the shape of a turkey leg and was thus nicknamed that over the course of its career. The aircraft was powered by two turbojet engines seated along the sides of the lower fuselage, aspirated through semi-circle intakes found along the forward fuselage sides and exhausted through individual nozzles under the sides of the tail unit. The undercarriage was typically carrier-like - two single-wheeled main legs and a dual-wheeled nose leg, all three legs retractable into the frame. The all-weather requirement was aided by a terrain display CRT system to which the navigator/bombardier utilized for their low-level attack runs. A permanently fixed in-flight refueling probe was fitted over the nose between the forward cockpit windscreens and used to further extend the operational reach of the aircraft. The tail unit consisted of a single vertical tail fin with swept-back horizontal planes.
From the outset, the A2F-1/A-6 was designed around a large bomb load out and this necessitated a specialized approach to the wings which could enable the aircraft to carry potent payloads while maintaining the necessary strength and capabilities for subsonic flight. With a high-mounted installation, the underwing hardpoints were cleared from any ground interference and offered the needed performance handling during low-level runs while retaining agility against ground-based fire. Airbrakes were integrated into the wings for additional stabilizing support. The avionics suite was of an advanced nature for the period with automation built-in as well as diagnostic measures to aid technicians and the flight crew. This sort of sophisticated design nature made the A-6 a high maintenance machine.
Armament was set across five total hardpoints that included four underwing and one under fuselage position for a total of 18,000lb of externally-held stores. The A-6 would eventually see a career carrying everything from air-to-air missiles, air-to-surface missiles, anti-radar missiles, rocket pods, and a plethora of general purpose drop bombs. Precision-guided munitions followed in time and a nuclear-drop capability was always a part of her design. There was no internal gun fitted. Additionally, the aircraft could carry external drop tanks across any of its five hardpoints for all positions were plumbed.
Grumman completed eight airframes for the preliminary and developmental testing phases. These led to the initial A-6A production models which would eventually number 480 units (USN designations moved to a new standard in 1962). The first operational squadron to be issued the A-6A was VA-42 on February 1st, 1963 and the type was adopted for service with both the USN and the United States Marine Corps (USMC) serving as the primary strike arm of USN carrier groups.
As a carrier-based aircraft, the A-6 was given the usual carrier-minded qualities to assist in its operation in an over-water environment. Its undercarriage was reinforced for the rigors of deck service (complete with the double-tired nose landing gear leg) and an arrestor (tail) hook was added under the empennage to snag awaiting deck cables when landing. For storage on the space-strapped carriers of the day, the A-6's wing mainplanes folded upwards at about their midway length to promote a more contained profile when held below deck.
The A-6's baptism of fire occurred in the long-running Vietnam War (1955-1975). By the mid-1960s, America's commitment in the region had grown to the point that any and all available military hardware was sent to the region in an attempt to turn the tide against the invading Soviet-supported North. The A-6 was up to the challenge with well-trained crews and long-ranged capabilities while carrying an incredible amount of ordnance against enemy ground targets. Of course, the low-altitude runs expected of the aircraft opened it up to intense enemy ground fire (including Surface-to-Air Missile (SAM) strikes) from all quarters and some eighty-four A-6s were lost in the war. Nevertheless, the A-6 became just one of the many American military symbols of the Vietnam War - joining the storied McDonnell Douglas F-4 Phantom II fighter, the Bell UH-1 "Huey", and others in the fray.