Curtiss A-8

Last revised July 1, 2000

Throughout the 1920s, the United States Army had operated just one combat group (typically with three squadrons) which was assigned the mission of attack. This was the 3rd Attack Group, which had initially operated DeHavilland DH-4s and later transitioned to Curtiss A-3 Falcon biplanes. By 1930, however, the era of the military biplane was clearly nearing its end, and the Army Air Corps initiated a contest for the next generation of attack planes which would be all-metal, low-winged monoplanes designed specifically for the attack role.

The Curtiss entry in the contest was the XA-8. The A-8 was the first Curtiss tactical monoplane built for the U.S. Army, all previous designs by this company for the US Army having been biplanes. The A-8 had many advanced features, including an all-metal structure with an all-metal covering. It had trailing edge flaps and full span leading-edge slats, and had enclosed cockpits. The A-8 was the first Army Air Corps plane to feature trailing edge flaps, and the enclosed cockpits were the first to be installed on a US combat plane. However, the thin low-mounted wings were externally braced with struts and wires, which was definitely a throwback to an earlier era.

The crew sat in widely-separated individual cockpits. The pilot sat well forward in a completely enclosed cockpit and controlled four 0.30-inch machine guns that were mounted in the undercarriage fairings in such a way that their field of fire cleared the propeller arc. The rear cockpit was provided with its own separate canopy and was fitted with a single 0.30-inch flexible machine gun. Underwing racks could carry up to 400 pounds of bombs.

The name Shrike was commonly applied to the aircraft, but the name was a company name, and was not used by the US Army.

The first XA-8 (Model 59) was flown in June of 1931. It bore the Army serial number of 30-387. It was powered by a single 600 hp Curtiss V-1570C Conqueror water-cooled V-12 engine driving a fixed-pitch three-bladed propeller. It competed with the General Aviation (Fokker) XA-7 in the attack plane contest. The XA-8 was judged the better of the two designs and won an order for 13 service-test models that was placed on September 29, 1931.

The first five of these service test aircraft were designated YA-8 (Model 59A, serials 32-344/348). They were similar to the XA-8 except for the use of Prestone-cooled V-1570-31 engines. The remaining eight were designated Y1A-8 (serials 32-349/356), the Y1 prefix meaning that they were purchased with F-1 funds rather than from regular appropriations. All of these planes were redesignated A-8 upon the completion of service testing.

Eleven A-8s (32-345/32-355) were issued to the 3rd Attack Group based at Fort Crockett, Texas during 1932, where they served alongside the unit's Curtiss A-3B Falcon biplanes. At this time, the 3rd Attack Group was the Army's only group devoted solely to attack.

The last Y1A-8 (32-356) was converted to Y1A-8A with a 657 hp geared Curtiss V-1570-57 engine and a revised wing. The geared Conqueror was less noisy but was heavier than the standard model. The gross weight increased to 6287 pounds. The Y1A-8A was delivered to Wright Field for tests in October 1932. In spite of the increased power, the top speed dropped 3 mph to 181 mph. The Y1A-8A was later redesignated A-8A, and was issued to the 3rd Attack Group in September of 1933.

The field trials with the A-8 were sufficiently successful that 46 production variants were ordered under the designation A-8B on February 27, 1933.

The first YA-8 (32-344) was returned to the Curtiss factory in Buffalo, New York for tests with a 625 hp Pratt & Whitney R-1690D Hornet 9-cylinder air-cooled radial engine. Following the change of engines, the aircraft was redesignated YA-10. With the new powerplant, the plane was returned to Wright Field on September 8, 1932. Tests proved that the Hornet radial engine was superior to the liquid-cooled Conqueror engine for attack aircraft. It was true that air-cooled radials were less streamlined than liquid-cooled engines, but they were less expensive to operate and did not have complex radiators that were especially vulnerable to enemy fire. The Army was so impressed that it decided that subsequent Shrikes would be delivered with radial engines, and requested that the 48 A-8Bs on order were to switch from the geared V-1570-57 engine to the air cooled Wright Cyclone radial, this change resulting in a redesignation to A-12.

Specification of Curtiss YA-8:

Engine: One 600 hp Curtiss V-1570E Conqueror liquid-cooled V-12 engine. Performance: Maximum speed 183 mph at sea level. Cruising speed 153 mph at sea level. Stalling speed 64 mph. Initial climb rate 1325 feet per minute. Service ceiling 18,100 feet. Range 480 miles. Dimensions: Wingspan 44 feet 0 inches, length 32 feet 0 inches, height 9 feet 0 inches, wing area 256 square feet. Weights: 3910 pounds empty, 5888 pounds loaded. Armament: Four forward-firing 0.30-inch machine guns. One flexible 0.30-inch machine gun operated by rear observer. Ten 30-pound bombs could be carried internally, or four 100 pound bombs externally. Armament: Four forward-firing 0.30-inch machine guns. One flexible 0.30-inch machine gun operated by rear observer. Ten 30-pound bombs could be carried internally, or four 100 pound bombs externally.


  1. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.

  2. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.

  3. Curtiss Aircraft, 1907-1947, Peter M. Bowers, Naval Institute Press, 1979.

  4. The Curtiss Shrike, Kenn C. Rust and Walter M. Jefferies, Jr., Aircraft in Profile, Doubleday, 1969.