A2J encore: The North American D-190

The North American A2J "Super Savage" is one of the lesser-known US Navy combat aircraft types built in the early Cold War, having constituted an endeavor by North American to adapt the AJ Savage design to use gas turbine engines but whose turboprop engines were beset by teething troubles. Even before the A2J flew, however, North American Aviation conjured up the idea of adapting the A2J design for a wide array of both attack and non-combat missions, including close air support. 

In October 1950, the US Navy's Bureau of Aeronautics issued a specification for a general-purpose attack bomber capable of operating from modernized Essex-class aircraft carriers and small airfields, dubbed XVA(GP) by BuAer. This notional aircraft was also to be used by the US Marine Corps for close air support, and minimum requirements called for a payload of four 20 mm guns, three bombs, and twenty unguided rockets, an endurance of at least four hours on close air support missions (of which at least two hours would be on station at altitudes of 5,000 to 25,000 feet [1,524 to 7,620 meters]), and cruising speed, altitude, and service ceiling compatible with those of escorting general-purpose fighters. In addition to attack, the notional XVA(GP) aircraft would also be optimized for ECM, target towing, reconnaissance, airborne early warning, and photographic reconnaissance.

A manufacturer's model of the North American D-190 general-purpose attack aircraft.

In the fall of 1951 North American Aviation envisaged a proposal for a derivative of the XA2J to fulfill the parameters specified in the XVA(GP) requirement. Internally designated D-190, it was powered by two Allison T40-A-8 turboprops driving two contra-rotating propellers each measuring 14 feet (4.27 meters in diameter) and differed from the XA2J in having longer engine nacelles, a more blended upper fuselage, horizontal stabilizers with increased wingspan and surface area, and a wing thickness/chord ratio of 12 percent. It was 54 feet 11 in (16.74 meters) long and had a wingspan of 65 feet 9 in (20.04 meters) with tip tanks (61 feet 10 in [18.85 meters] without tip tanks), a height of 21 feet 1.92 in (6.45 meters), and a wing area of 766.87 ft2 (71.32 m2); the wings of the D-190 spanned 37 feet 2 in (11.33 meters) when folded. Gross weight without the tip tanks was to be 58,280 lb (26,436 kg), and maximum carrier takeoff would be 61,300 lb (27,806 kg), while top speed was 576 mph (927 km/h) at 24,000 feet (7,315 meters). A number of sources quote A2J-2 for the D-190, but this is not borne out by official documents, which indicate that XA2J-2 was applied to a proposed XA2J-1 with slightly increased gross weight.

The D-190 had four 20 mm cannons or alternately twelve 0.5 in (12.7 mm) machine guns in the lower nose, and offensive armament consisted of 6,000 lb (2,721 kg) or 12,000 lb (5,443 kg) of bombs along with mines, unguided air-to-ground rockets, and napalm tanks. When configured for nuclear strike missions, the D-190 was to carry a single Mk. 5 nuclear bomb and operate from modified Essex-class carriers as well as the Midway- and Oriskany-class carriers. As a land-based close support machine, it would have a gross weight of 67,899 lb (30,798 lb) and loiter over an enemy target for three hours at a range of about 345 miles (556 km), and North American also envisioned the D-190 as a photographic reconnaissance aircraft.

As it turned out, most of the design estimates for the D-190 did not meet the performance parameters outlined in the BuAer's XVA(GP) requirement, including range. Therefore, the D-190 project went no further than the drawing board. 

References:

Buttler, T., 2010. American Secret Projects: Bombers, Attack, and Anti-Submarine Aircraft 1945 to 1974. Hinckley, UK: Midland Publishing.

Buttler, T., 2021. American Secret Projects 4: Bombers, Attack, and Anti-Submarine Aircraft 1945 to 1974. Manchester, UK: Crécy Publishing.

Friedmann, N., 2022. U.S. Navy Attack Aircraft 1920-2020. Annapolis, MD: Naval Institute Press.

Ginter, S., 1992. North American AJ-1 Savage (Naval Fighters No. 2). Simi Valley, CA: Ginter Books.