The A-6E was the definitive production version of the Intruder. The A-6E was externally identical to the A-6A, but featured much more advanced electronics, and successive upgrades were made throughout the years which progressively increased the capabilities of this warplane.
Work on the A-6E began in June of 1966. The A-6E was outwardly identical to the A-6A, but the A-6E had an AN/ASQ-133 solid-state digital computer replacing the AN/ASQ-61 unit of the A-6A In addition, an AN/APQ-148 multimode-radar replaced the separate search and track radars of the A-6A. The AN/ALQ-100 deceptive jammer was moved to the wing root inside a sawtooth-shaped extension to the leading edge. Grumman originally proposed that a built-in cannon armament be added, but this suggestion was rejected by the Navy. The A-6E was powered by two 9300 lb.s.t. Pratt & Whitney J52-P-8B turbojets, not very different from the P-8A engines of the earlier A-6A
A-6A BuNo 155673 was modified as the development aircraft for the A-6E, and flew for the first time on February 27, 1790. It was fitted with the new computer system in August, and flew with the AN/APQ-148 radar in November. After completion of the trials, 155673 was returned to standard A-6A configuration.
After completion of the 482nd A-6A in December of 1970, Grumman decided on its own to switch the production line over to the A-6E version. However, deliveries had to be temporarily halted while the A-6E underwent trials, and no Intruders were delivered during the next eight months, and only one was delivered in each of the next three months. After this, deliveries of the A-6E were made at regular intervals, except during the late 1970s and early 1980s when reduced defense budgets reduced delivery rates to only three aircraft per year.
The first deployable Navy squadron to get the A-6E was VA-85, which got its first E on December 9, 1971.
At the same time as new A-6As were being delivered, 240 existing A-6As were rebuilt to A-6E standards.
During the production run of the A-6E, numerous improvements were introduced, so many in fact that late A-6Es are very much more capable machines than were the initial production A-6Es.
In the 1970s, the CAINS (Carrier Airborne Inertial Navigation System) A-6E was introduced. It employed the Litton AN/ASN-92 inertial navigation system that replaced the AN/ASN-31 of earlier A-6Es. These CAINS planes can be recognized by the presence of an additional air scoop on the dorsal spine of the aircraft which feeds an additional air-conditioning turbine.
In September of 1979, the Target Recognition Attack Multi-sensor (TRAM) A-6E was introduced. The heart of the system was the AN/AAS-33 TRAM turret, which provided the ability to detect and track targets by their infrared emission, and also allowed the aircraft to self-designate targets for attack by laser-guided weapons. The turret was located underneath the nose, just forward of the nosewheel, and housed a laser and infra-red targeting system with a laser designator, laser rangefinder, and forward-looking infrared (FLIR) sensor. The turret was gyro-stabilized, with the laser systems co-linearly mounted on the FLIR to ensure boresight of the laser beam with the FLIR. The laser can be used to measure slant range calculations for more accurate attacks, or can be used to designate targets for delivery of laser-guided weapons. In addition, the TRAM system can be slaved to the radar. The infrared image from the FLIR can be displayed on a cathode ray tube mounted above the bombardier/navigator's radar scope. The system enables the aircraft to identify targets and make an an attack in either day or night. The TRAM A-6E is also fitted with an AN/APQ-156 radar in place of the earlier AN/APQ-148. The APQ-156 provides search, ground-mapping, tracking, and ranging of both fixed and moving targets. In addition, it performs terrain-following and terrain-avoidance functions as well as beacon detection and tracking. During an attack, the target image is locked into the weapon system, keeping the turret's sensors aiming at the locked-in point even as the aircraft maneuvers. In addition, an AN/ASQ-155 computer is provided.
The first TRAM A-6E (BuNo 155673) flew on March 22, 1974, but development was slow and it was not until November 29, 1978 that the first production TRAM A-6E was ready (BuNo 160995). The first TRAM A-6E was delivered to the Navy on December 14, 1978. The first deployment with an A-6E TRAM took place on September 10, 1979 with VA-35 aboard the USS Nimitz. Ultimately 228 A-6Es were converted to TRAM configuration. The TRAM system was widely used during Desert Storm. The famous footage from Desert Storm which depicted what General Norman Schwartzkopf described as "the luckiest man in Iraq", shows a TRAM view during an A-6E attack on a bridge. A truck just happened to cross the bridge immediately before the laser-guided bomb hit.
The TRAM/DRS (Detection and Ranging Set) was a refinement of the basic TRAM that began to be delivered in 1979.
By the mid-1980s, many A-6Es were beginning to approach a quarter-century in age, and were beginning to show signs of fatigue. By 1988, 62 A-6E had to be grounded and a further 119 had to be restricted to maneuvers below 3 gs because of metal fatigue in the wings. Consequently, the Navy embarked on a program to prolong the life of the Intruder by giving them new wings. The Navy opted to rewing the A-6E fleet with a new composite graphite/epoxy/titanium/aluminum wing manufactured in kit form by Boeing-Wichita. The new wing was largely made of composite material, but the moving surfaces were still made of aluminum. The wing was supposedly stronger and longer-lasting, with better resistance to corrosion. However, there were problems with structural failures in the joints, and there were delays in the rewinging program. The first composite wing aircraft was delivered in October 1990. By January 1995, 85 percent of the A-6E fleet had been re-winged.
The original plan was for all A-6Es to be rewinged and to go through a Systems Weapons Improvement Program (SWIP). The SWIP integrated stand-off weapon capabilities into the A-6E, including the ability to carry and launch the AGM-65E/F laser/imaging infrared Maverick, the AGM-84A Harpoon, the AGM-84E SLAM (Stand-off Land Attack Missile) and the AGM-88 HARM antiradiation missile. The upgrade also involved some new survivability improvements such as a fire warning and extinguishing system. The aircraft had a fully digital armament system. However, some of the SWIP upgrades did not get the new composite wing because of delays in the rewinging program. Consequently, there were A-6E SWIP aircraft with the original metal wing as well as A-6E SWIP Block 1 aircraft with the composite wing.
The A-6E SWIP Block 1A variant has the ASN-139 inertial navigation system, the ARN-118 TACAN, a GPS navigation system, and a new heads-up display.
Engines: Two Pratt & Whitney J52-P-8B non-afterburning turbojets, 9300 lb.s.t. each.
Performance: Maximum speed 644 mph at sea level (653 mph clean). Cruising speed 474 mph. Stalling speed 142 mph.
Service ceiling 42,400 feet. Combat ceiling 40,250 feet. Norman range 1010 miles.
Maximum ferry range 3300 miles.
Weights: 26,800 pounds empty, 54,400 pounds gross, 60,400 pounds maximum.
Dimensions: Wingspan 53 feet 0 inches, length 54 feet 9 inches, height 16 feet 2 inches, wing area 529 square feet.
Armament: No cannon armament. A maximum weapons load of 15,000 pounds could be carried on four underwing hardpoints and one centerline hardpoint.
151558/151612 Grumman A2F-1 Intruder Redesignated A-6A in 1962 151558, 151562, 151564, 151565, 151573, 151591/151593 brought up to A-6E standards. 156994/157029 Grumman A-6A Intruder 156995/156997, 157000/157006, 157009/157014, 157016, 157017, 157019, 157021, 157023/157027, and 157029 brought up to A-6E standards. 151780/151827 Grumman A-6A Intruder 151782, 151784, 151790, 151802, 151804, 151807, 151811/151812, 151814, 151820 brought up to A-6E standards. 152583/152646 Grumman A-6A Intruder 152583/152585, 152587, 152591, 152593, 152596, 152599, 152600, 152603, 152607, 152610, 152614, 152617, 152620, 152621, 153623, 152630, 153634, 152635, 152640/152642, 152645 brought up to A-6E standards. 152891/152954 Grumman A-6A Intruder 152895, 152902, 152904, 152905, 152907, 152908, 152912, 152915, 152916, 152918, 152923/152925, 152928/152931, 152933, 152935, 152936, 152941, 152943, 152945, 152947, 152948, 152950, 152953, 152954 brought up to A-6E standards. 154124/154171 Grumman A-6A Intruder 154124, 154126, 154128, 154129, 154131, 154132, 154134/154137, 154140, 154142, 154144, 154146, 154148, 154151, 154154, 154156, 154158, 154159, 154161/154163, 154167/154171 brought up to A-6E standards. 155581/155721 Grumman A-6A Intruder 155673 modified as development aircraft for A-6E and later returned to A-6A configuration, but was again modified as A-6E. 155581/155721 Grumman A-6A Intruder 155581/155586, 155588/155592, 155595/155600, 155602, 155604, 155606, 155608, 155610, 155612, 155615/155617, 155619/155621, 155623/155625, 155627/155633, 155625/155638, 155642/155646, 155648, 155649, 155651, 155653/155662, 155664, 155665, 155667/155670, 155672/155676, 155678/155685, 155687/155689, 155692, 155694, 155695, 155697/155699, 155702/155704, 155706/155708, 155710/155719 brought up to A-6E standards.
158041/158052 Grumman A-6E Intruder 158528/158539 Grumman A-6E Intruder 158787/158798 Grumman A-6E Intruder 159174/159185 Grumman A-6E Intruder 159309/159317 Grumman A-6E Intruder 159895/159906 Grumman A-6E Intruder 160421/160431 Grumman A-6E Intruder 160993/160998 Grumman A-6E Intruder 161082/161093 Grumman A-6E Intruder 161100/161111 Grumman A-6E Intruder 161112/161114 Grumman A-6E Intruder contract cancelled. 161230/161235 Grumman A-6E Intruder 161236/161241 Grumman A-6E Intruder Contract cancelled. 161659/161690 Grumman A-6E Intruder 161691/161694 Grumman A-6E Intruder contract cancelled. 161886/161897 Grumman A-6E Intruder contract cancelled. 162179/162222 Grumman A-6E Intruder 164376/164385 Grumman A-6E Intruder