The McDonnell Douglas A-12 "Avenger II" was slated to become the United States Navy's (USN) first stealth aircraft. The type exhibited all sorts of technological advancements that would have made it one of the finest naval aircraft anywhere in the world, however, the project was doomed by ballooning costs and lack of progress. In the end, the A-12 fell to the politician's pen and was terminated - no aircraft were ever produced and millions upon millions were spent on its development.
The true operational capabilities of "stealth" aircraft were unveiled in the 1991 Persian Gulf air war when a pair of Lockheed F-117 Nighthawk "stealth fighters" opened the conflict by entering undetected into enemy airspace, dropping precision-guided munitions on their targets and exiting back to safety. When details of the aircraft came to light, it was found that development and testing were rooted back in the 1970s with the aircraft becoming operational in the USAF inventory in the early 1980s under the strictest levels of secrecy.
Not lost on the benefits of stealth technology, the United States Navy moved to replace their aging fleet of Grumman A-6 Intruders (particularly the A-6E). The A-6 saw her origins in a requirement dating back to the late 1950s and first flew in 1960 ultimately entering service with the USN in 1963. The type served in quantity from the deck of American aircraft carriers throughout the Vietnam War and was also fielded in the Persian Gulf War before seeing retirement in 1997. While less than 700 were built, the aircraft formed the strike arm of USN operations across the globe for decades.
The USN initiated their Advanced Tactical Aircraft (ATA) program in 1983 to find a suitable replacement for the aging A-6. As a carrier-based endeavor, the new aircraft type would have to be designed with the rigors of carrier deck operations in mind including folding wings, a strong undercarriage and internal structure and counter the corrosive effects of the life at sea. Lift properties would also be important for short-take offs from carrier decks, though assisted by steam catapults. In line with the F-117, the new Navy aircraft would be designed around the latest radar-reducing technologies and internal systems as well as carry a comparable ordnance payload to the A-6 it would be replacing in fleet service. Optimistically, the USN sought to have their A-6 aircraft retired and their new strike platforms ready by 1994.
US defense powerhouses naturally jumped at the chance to deliver the Navy's first stealth aircraft and those involved included a joint effort from McDonnell Douglas and General Dynamics as well as a triad formed by Northrop, Grumman and Vought. McDonnell Douglas was a house-hold name for its excellent F-15 Eagle air superiority fighter while General Dynamics made a name for itself with the F-111 Aardvark strike fighter and the F-16 Fighting Falcon lightweight fighter. Northrop was well-known throughout the aviation industry for decades concerning a slew of military aircraft designs while Grumman was responsible for the venerable F-14 Tomcat interceptor. Vought, known more for their World War 2-era F4U Corsair, had more recent successes with their F-8 Crusader and A-7 Corsair strike fighters. Of note here is that the F-14, F-8 and A-7 were all carrier-capable designs. The US DoD awarded both sides design-level contracts in late 1984 and, some two years later, concept-level contracts were handed out for continued development of the respective designs. In early 1988, only the McDonnell Douglas/General Dynamics team submitted their work for review and won the defense contract. The new aircraft was to be designated as the "A-12 Avenger II", the Avenger moniker in honor of the USN's other famous World War 2 carrier aircraft - the Grumman TBF Avenger torpedo bomber. The "A" in the designation assumed "attack" capabilities as in the A-6 Intruder.
The MD-General Dynamics design was utterly impressive by late-1980s standards - even moreso than the faceted F-117 shape of a decade before. The aircraft was designed around an isosceles triangle shape when viewed in the overhead profile and this led to the aircraft being nicknamed the "Flying Dorito" in some circles - the resemblance mimicking the famous tortilla chip brand. There were no vertical tail surfaces of any kind which made the A-12 a true "flying wing". The two-person cockpit was situated at the apex of the triangle, running to about amidships and under a three-piece canopy. The fuselage and were a single well-contoured consistent shape. Such shapes - or flying wings - held several inherent design advantages in that they naturally reduced surface drag, promoted lift and could manage much more internal space than traditionally arranged aircraft. This allowed the type to carry more fuel and greater ordnance loads (both internally) which broadened their tactical usefulness. Intakes were featured at the underside of the fuselage towards the front of the triangle shape, just under the cockpit. Both of the pilots were seated in tandem with the canopy (initially) slated to open to the side (a later redesign saw this now conventionally hinged at the rear). The rear area of the aircraft was essentially featureless and smooth in its overall contour. The wingtips were basic triangle points and the entire planform tapered from the thicker smooth leading edge to the thinner rear trailing edge. The "base" of the triangle where the engines exhausted was straight in its design. Construction of the Avenger would have included lightweight composites to help keep operational weights down while combating the salty air and sea. The undercarriage consisted of two main single-wheeled landing gear legs and a double-tired nose landing gear leg. Wing folding would have occurred outboard of the main landing gear legs utilizing a forward-set pair of hinges. All told, the A-12 exuded technology in its basic appearance.
Internally, the pilot sat in the forward cockpit with access to three large, full-color, multi-function display screens and a conventional flight stick column. All systems were within easy reach and vision through the canopy was unobstructed and relatively excellent. For the systems officer in the rear cockpit, flight controls were redundant and four full-color, multi-function displays dominated the position front. MFDs could relay pertinent mission parameters, weapons information and flight details in real-time and, with a push of a button, programmed presets could be utilized. Automated systems throughout the design would have assisted the crew in various functions including identifying and reacting to threats from inbound homing and guided missiles. In unison, the tandem group with their advanced systems would have been able successfully compete on the then-modern battlefield.
All weapons would have been serviced through an internal weapons bay, helping to keep the aircraft's external surfaces as minimal as possible. The internal bay held a collective maximum threshold of 5,100lbs concerning ordnance or equipment depending on mission type. A typical ground attack configuration would have seen the A-12 fielded with precision-guided drop bombs or these replaced by conventional drop bombs. Beyond its ground attack facilities, the A-12 was also designed to engage aerial targets with applicable munitions. For air-to-air combat, the A-12 would have fielded the AIM-120 AMRAAM medium-ranged air-to-air missile and, most likely, the then-current version of the AIM-9 Sidewinder short-ranged air-to-air missile. Its mission scope could also have been branched out to include reconnaissance and electronic warfare roles should the aircraft had come to term. For the radar suppression role, the A-12 would have been cleared to use the AGM-88 HARM anti-radiation air-to-surface missile.
Dimensionally, the A-12 exhibited a wingspan of 70 feet. This was dramatically reduced when the wings were folded for carrier storage to just 36 feet. The fuselage had a running length of 37 feet, 10 inches with an overall height of 11 feet when the aircraft was at rest. The A-12 would have measured nearly half the length of the F-14 or the A-6 in a carrier hangar. Empty weight was listed at approximately 40,000lbs with a maximum take-off weight nearing 80,000lbs. Power would have been supplied by a pair of General Electric F412-GE-D5F2 engines buried deep within the fuselage. These were non-afterburning turbofan engines (to help reduce heat signatures at the cost of speed) and outputted at 13,000lbs of thrust each. Top speed was estimated at around 580 miles per hour with an operational range of 920 miles, a service ceiling nearing 40,000 feet and rate-of-climb of 5,000 feet per minute.
McDonnell Douglas marketing material sold the Avenger II as an aircraft featuring all of the qualities required for the ever-evolving USN mission of the time. Its low-observable nature would have allowed it to break through the enemy air defense network without revealing its presence to active ground stations - inherently increasing mission survivability rates for the pilots - until the absolutely last possible second, which left little time for the enemy to react. The aircraft's internal payload capacity, coupled with sophisticated onboard systems, would have allowed for use of precision-guided weaponry to meet the new demands of the American air campaigns to follow. As a flying wing design, internal fuel stores would have given the A-12 excellent ranges without requiring refueling when compared to the then-existing options available to the USN. Of course marketing material also touted the aircraft's quick turn-around time and low long-term support costs - staple qualities of any aircraft "in development" and not proven in-the-field.
McDonnell Douglas expected the aircraft to be ready by mid-1990. While primary interest in the A-12 was held by the USN, it was only natural that the USMC would see a need to upgrade their stable of aircraft in turn. Additionally, the USAF entertained the notion of procuring the A-12 as well, to a certain extent, and this would have been a slightly revised land-based version of the naval design. The USN contemplated purchasing some 620 examples with the USMC receiving a further 238 all their own. USAF interest was such that 400 aircraft were slated to be procured.
However, all for the A-12 program began to unravel by 1990. Delays, inevitable cost overruns and design issues began to plague the project before even a single aircraft had been built. The aircraft was now proving to be much heavier than originally anticipated and problems with the advanced systems soon arose - particularly with the aperture radar and avionics intended to be installed. The composite structure was proving a nuisance of sorts and forced the use of metals instead, bloating the overall weight in the process - the A-12 was now some 30% over the required operating weight. The projected costs of continued development led to a natural "tightening of the noose" around the stealth project. While the original first flight was intended for late 1990, the revised schedule showcased a later date sometime in 1992.
Regardless of the efforts being made to keep the A-12 program viable, the US Secretary of Defense - then one Richard "Dick" Cheney - was not convinced of the projects long-term investment. With no aircraft to show for the millions of tax payer dollars already poured into the program and no concrete dates being delivered by the contractors, Cheney used his authoritative powers to cancel the A-12 Avenger II outright on January 7th, 1991. The story of the A-12 did not end there for, in the years following, there have been countless litigation efforts from both the federal government and the contractors involved to recoup lost project costs - litigation that has yet to be settled in American courts to this very day (now 2012, some 20+ years since the project's start). The loss of the A-12 went on to have several ripple effects in the US defense world - the A-6 was still retired though not until 1997 and replaced by the F/A-18 Super Hornet while McDonnell Douglas' financial sufferings forced it to team with powerhouse Boeing for its sheer survival (MD is now a subsidiary of the Boeing brand).
It is believed that only one full-size mockup of the A-12 was ever completed. Recent reports have also showcased the canopy section believed to be of the A-12 appearing on eBay, its origin being somewhat cloudy but the product believed to be authentic nonetheless (based on available serial numbers found on the parts). At the point of its cancellation, the A-12 program was the largest and costliest cancellation undertaken by the US DoD.
Update February 2014: It was revealed that the United States Navy had ended its long-running agruement with General Dynamics and Boeing over the settlement of the A-12 project. The U.S. government has elected to take a $400 million dollar settlement to end the decades of legal wrangling between all parties.