The Grumman A-6 Intruder is an American twinjet all-weather attack aircraft developed for the U.S Navy.
The Grumman A-6 Intruder is a two-seat twin-engined monoplane, equipped to perform carrier-based attack missions regardless of prevailing weather or light conditions.
The cockpit used an unusual double pane windscreen and side-by-side seating arrangement in which the pilot sat in the left seat, while the bombardier/navigator (BN) sat to the right and slightly below to give the pilot an adequate view on that side.
In addition to a radar display for the BN, a unique instrumentation feature for the pilot was a cathode ray tube screen that was known as the Vertical Display Indicator (VDI).
This display provided a synthetic representation of the world in front of the aircraft, along with steering cues provided by the BN, enabling head-down navigation and attack at night and in all weather conditions.
The A-6’s wing was relatively efficient at subsonic speeds, particularly when compared to supersonic fighters such as the McDonnell Douglas F-4 Phantom II, which are also limited to subsonic speeds when carrying a payload of bombs.
The wing was also designed to provide a favourable level of manoeuvrability even while carrying a sizable bomb load.
A very similar wing would be put on pivots on Grumman’s later supersonic swing-wing Grumman F-14 Tomcat, as well as similar landing gear.
For its day, the Intruder had sophisticated avionics, with a high degree of integration.
To aid in identifying and isolating equipment malfunctions, the aircraft was provided with automatic diagnostic systems, some of the earliest computer-based analytic equipment developed for aircraft.
These were known as Basic Automated Checkout Equipment, or BACE (pronounced “base”).
There were two levels, known as “Line BACE” to identify specific malfunctioning systems in the aircraft, while in the hangar or on the flight line; and “Shop BACE”, to exercise and analyse individual malfunctioning systems in the maintenance shop.
This equipment was manufactured by Litton Industries.
Together, the BACE systems greatly reduced the Maintenance Man-Hours per Flight Hour, a key index of the cost and effort needed to keep military aircraft operating.
The Intruder was equipped to carry nuclear weapons (B43, B57, B61) which would have been delivered using semi-automated toss bombing.
Pre-production aircraft, eight built with the first four with rotating jet exhaust pipes, redesignated YA-6A in 1962.
First production variant with fixed tailpipe, 484 built, redesignated A-6A in 1962.
Prototype electronic warfare variant, one modified from A2F-1, redesignated YEA-6A in 1962.
Electronic warfare variant of the A2F-1 redesignated EA-6A in 1962
Pre-production aircraft redesignated from YA2F-1 in 1962.
First production variant redesignated from A2F-1 in 1962.
One YA2F-1 electronic warfare variant prototype redesignated in 1962.
Electronic warfare variant redesignated from A2F-1H, had a redesigned fin and rudder and addition of an ECM radome, able to carry under wing ECM pods.
The redesignation of three YA-6As and three A-6As.
The six aircraft were modified for special tests.
One EA-6A aircraft was modified for special test purposes.
Proposed trainer variant with three-seat, not built.
Variant fitted with avionics for the suppression of enemy air defences (SEAD).