Navy Nearly Got A Single-Seat A-6 Intruder Instead Of The A-7 Corsair II
The story of how a major modification of Grumman’s A-6 Intruder almost replaced the A-4 Skyhawk in the Navy’s light attack role.
When the U.S. Navy called for a new light attack aircraft to replace the Douglas A-4 Skyhawk in the early 1960s, the competition that followed was stiff. Top players including Douglas, North American, Vought, and Grumman were all in the running, with Grumman’s pint-sized A-6 Intruder derivative, in particular, being something of a historical aviation oddity.
The evolution began when the Navy decided they wanted more from the A-4 Skyhawk, a subsonic, single-seat light attack aircraft originally introduced in 1956. The branch needed more payload capacity and more range to meet evolving mission requirements. The Navy first had its eyes on replacing it with the proposed Douglas A4D-6, an enlarged development of the Skyhawk that would have been powered by a Pratt & Whitney TF30 turbofan engine and was expected to easily meet payload and range requirements.
At first, the Navy also wanted the A-4’s replacement to go supersonic, as outlined in the VAX program that initially sought to field a Skyhawk successor. The VAX requirements were quickly realized to be too lofty and expensive for the short-term A-4 replacement that the Navy needed, and it was clear the A4D-6 would struggle to achieve supersonic speeds.
With a supersonic light attacker now out of the question, the Navy went back to the drawing board, still with a heavy bias toward the A4D-6 because of its close relationship to the Skyhawk. However, a counter-marketing effort led by Connie Lau, who was chief of advanced systems for Vought at the time, convinced the Navy to foster some healthy competition instead.
A new requirement for the subsonic VA(L) competition was then issued in 1963 to address the need for an A-4 replacement in the interim, and the VAX program was put on the back burner for the time being. The VA(L) program, with 'V' standing for heavier than air, 'A' for attack, and 'L' for lightweight, specified that the Skyhawk replacement would retain a single-seat configuration and utilize one aforementioned Pratt & Whitney TF30 turbofan. The aircraft would be armed with twin 20mm cannons and be able to carry at least 12 Mk 82 Snakeye bombs, totaling 6,000 pounds, over a combat radius of more than 600 nautical miles.
The VA(L) program required that companies in the running only submit entries based on existing designs, requiring as few modifications as possible. This was due to the need to drive down costs and achieve early availability.
With the specification parameters in place and the added benefit of basing the design on an existing aircraft, proposals from Vought, North American, Douglas, and Grumman flooded in. Douglas again submitted its souped-up A4D-6 version of the Skyhawk. North American took a similar route with an enlarged FJ-4 Fury proposal. Vought entered with a highly modified outgrowth of the F-8 Crusader known as V-463, and Grumman offered a single-seat modification of the company’s A-6 Intruder designated as G-128-12.
Grumman had initially considered a modification of its own F-11 Tiger fighter jet powered by the Navy-favored TF30 engine, before settling on modifying the Intruder, which was powered by twin Pratt & Whitney J52 turbojet engines. What followed was a portly mockup that was notably compact although still capable of meeting the payload and range requirements of the VA(L) program. But that isn’t to say the G-128-12 didn’t present its own problems.
An issue with spot factor, a metric that determines the handling and parking characteristics of aircraft on a carrier deck, including the smaller non-nuclear ones then in use, brought on by the mockup’s shape threatened the success of Grumman’s proposal. But the company soldiered on, incorporating a folding horizontal tail to address the spot factor challenges.
Grumman also replaced the A-6’s Digital Integrated Attack Navigation Equipment (DIANE) navigation and bombing system — a technological marvel of its day — with a less complex multimode radar. Additionally, the two-seat side-by-side cockpit of the Intruder was replaced by a single-seat-on-centerline cockpit layout.
Grumman went ahead with its offering, convinced that low development costs and the mockup’s derivation from the existing Intruder would outweigh any criticisms the Navy may have had. Unfortunately, this wasn't the case.
In February 1964, Vought was awarded the contract for its V-463 submission, based on the F-8 fighter.
Pushing the V-463’s commonality with the F-8 was a defining aspect of Vought’s proposal, but as development continued, the similarities between the two aircraft began to dwindle. It isn’t unheard of, though, for a design to meet this fate when being adapted to meet the requirements of a mission it wasn’t originally intended for. The F-8 was 'the last gunfighter,' a thoroughbred dogfighter, while the VA(L) outgrowth of it was, in essence, a bomb truck.
Vought also regards its VA(L) contract as one of the most unique in aerospace history. A webpage dedicated to the company’s heritage claims that the contract was the only true fixed-price contract to ever be issued for a major weapon system and goes on to explain that the terms were so rigid that the entire company could have been put out of business.
“For example, penalties were applied that required LTV to pay the Navy $50,000 per day per airplane (and there were six of them) for each day that Bureau of Inspection trials were delayed,” cites the Vought heritage page. “The weight target was missed by 600 pounds at a penalty to the company of $750,000. This was the only Navy requirement not met.”
The added weight came from an executive decision made by Sol Love, the Vought team’s engineering director for the competition, who insisted that reinforcing the aircraft’s wing would be worth the penalty in the long run. History dictates that he was right, as the added strength later allowed for the jet to be equipped with next-generation weapons and pods that would have required an expensive redesign otherwise.
If anything, the outcome was just unlucky for Grumman and the single-seat A-6 variant that could have been. The company really advocated for commonality with the Intruder, but in the end, the Navy wasn’t convinced.
Vought's smaller and lighter V-463 became the A-7A prototype that completed its initial flight in September 1965. The first delivery to the Navy took place the following year and the A-7A entered service in 1967 with Attack Squadron 147 (VA-147). The aircraft was deployed to Vietnam that same year. This is an amazing timeline by today’s standards, but even fast by those of the 1960s. Clearly, the VA(L) program did its job.
Officially named the Corsair II, the A-7 was generally known as the SLUF, or Short Little Ugly Fucker, on account of its portly appearance. Still, the stocky A-7 is revered by aviation enthusiasts as a workhorse in its own right, despite its complicated origin story.
In the end, the type would receive some of the most advanced avionics and sensors in the Navy’s aerial portfolio, and its ability to lift relatively massive bomb loads, as well as its significant endurance and economy, would see that it served the Navy until 1991. At that point, the F/A-18A/B Hornet, with its massive leap in multi-role capability, finally supplanted it, but the A-7 still had far superior endurance.
The U.S. Air Force would also come to realize the value in the humble A-7, with the type serving with that branch from 1970 until 1993. In addition to serving with Portugal and Thailand, the Hellenic Air Force retired the last operational A-7s in 2014, ending the legacy of the VA(L) program.
One ironic note worth mentioning is that the A-7 was eventually modified into the A-7F Strikefighter — which was supersonic capable. While it never went into production, in some ways, it completed the circle back to the genesis of original A-4 replacement requirements.
While the A-7 was definitely a success for all involved, one has to wonder what Grumman's single-seat, single-engine Intruder derivative would have brought to the table. If nothing else, it would have taken the A-6’s already bulbous ‘tadpole’ or ‘flying frying pan’ looks to a whole other level of strange.
Contact the author: Emma@thewarzone.com