During the final years of the Cold War the U.S. Military was pursuing four major programs in parallel to develop combat jets built around advanced radar evading stealth airframes. Of these, three were intended for the U.S. Air Force and all but one were intended for air to ground strike missions. The F-117 and B-2 both entered service as dedicated strike platforms, the former as a strike fighter in the early 1980s and the latter as a much larger intercontinental range strategic bomber in the late 1990s. These aircraft both served in the U.S. Air Force exclusively, and were followed by the F-22 Raptor air superiority fighter which was also used by no other country or service branch. It would remain the world’s only stealth aircraft with air to air combat capabilities for almost ten years from its entry into service in 2005. The fourth stealth aircraft of the period, which was the only one intended for the U.S. Navy and was a significantly more advanced strike design than the either the F-117 or the B-2, was the A-12 Avenger – a stealth fighter which rivalled the F-22 in sophistication.
The A-12 was intended to prove U.S. Navy carrier air wings with a long range strike capability, and would have replaced the A-6E intruder in that role. With the F-14D Tomcat heavyweight air superiority fighter introduced from 1991, it was expected that these too could potentially be replaced by carrier variants of the F-22 to provide carriers with two long range stealth aircraft – one for strike and one for air to air missions. As it was, both the A-12 and the carrier variant of the Raptor were cancelled in the Cold War’s aftermath, and carrier air wings were made much less versatile but a lot cheaper to operate exclusively using F-18E Super Hornets. The F-18E was a non-stealthy aircraft which was lighter and much shorter ranged than either the F-22 or the A-12. The end of the Cold War also saw the A-6 end production in 1992, and it was subsequently retired in 1997 as part of an effort to reduce operational costs of carrier groups by relying solely on the F-18.
The Advanced Tactical Aircraft program which would become the A-12 began development in 1983, a few years after the F-22, with McDonnell Douglas awarded the contract the following year. The aircraft were expected to be built in very large numbers, with the Navy expected to purchase 630 and the Marines around 240. The Air Force also considered purchasing up to 400 modified units to serve as ground based strike fighters to replace the F-111. The aircraft would have used the F412-GE-400 turbofan engine, a low maintenance design derived from the F404 use by the F-18, which in turn was used as a basis to develop the F414 engine for the F-18E, with commonality between the engines used by carrier based aircraft making maintenance easier.
The A-12 made use of a flying wing design, but had a highly unusual triangular shape which maximised stealth and payload. It was built to carry a sizeable arsenal of air to ground ordinance alongside two AIM-120 active radar guided long range air to air missiles and and two AGM-88 HARM anti radiation missiles in standard configuration. Internal weapons bays could accommodate tactical nuclear weapons such as the B61, and the overall internal weapons load was set at 2300kg. To place this payload in perspective, the new F-35 stealth fighter can carry just 1,100 kg of internal weapons, and just 680 kg for the F-35B variant. The F-22 meanwhile carries 910kg from its shallower bomb bays. The A-12’s combination of stealth, long range and high ordnance allowed it to penetrate deep into enemy airspace for offensive strike missions – a capability considered vital throughout the Cold War. With other carrier based fighters without stealth capabilities such as the F-18 and F-18E left effectively obsolete for any kind of deep penetration mission by advances in Soviet air defence technology, the A-12’s importance was high.
Continued in Part Two