The first Curtiss YA-8 (32-344) was held up at the factory for tests with a 625 hp Pratt & Whitney R-1690D Hornet 9-cylinder air-cooled radial engine in place of the Curtiss Conqueror V-12 liquid-cooled engine that powered the other A-8s that had been delivered to the Army. Following the change of engines, the aircraft was redesignated YA-10.
With the new powerplant, the plane was delivered to Wright Field on September 8, 1932. Flight tests proved that the radial engine was superior to the liquid-cooled Conqueror engine for attack aircraft. Air-cooled radials were less streamlined than liquid-cooled inline engines, but they were less expensive to operate and did not have to carry the complex radiators that were so vulnerable to enemy fire. The Army was so impressed with the radial-engined YA-10 that it decided that all subsequent examples would be delivered with radial engines, and immediately stipulated that the 48 A-8Bs then on order were to switch from the geared V-1570-57 engine to the air-cooled 670 hp Wright Cyclone radial, this change resulting in a redesignation to A-12.
On December 6, 1932, the YA-10 aircraft was sent to Fort Crockett for service testing, where it was assigned to the 13th Attack Squadron of the 3rd Group. It was transferred to Barksdale Field in Louisiana in July 1934 and served alongside the A-8s that had already entered service with the 3rd. It was then sent to the San Antonio Air Depot on April 29, 1934, from where it was assigned to the Command and General Staff College at Fort Leavenworth, Kansas on August 8, 1934. The A-10 was finally assigned to Chanute Field, Illinois on September 14, 1938. It was scrapped there on February 23, 1939.
A duplicate of the YA-10 was ordered for tests by the US Navy under the designation XS2C-1. The BuNo was 9377. It was delivered to the Navy in 1933, and some tests were carried out, but no further orders from the Navy were forthcoming.
Specification of Curtiss YA-10:
Engine: One 630 hp Pratt & Whitney R-1690D Hornet air-cooled radial
Performance: Maximum speed 174 mph at sea level. Cruising speed 148
mph at sea level. Stalling speed 67 mph.
Dimensions: Wingspan 44 feet 0 inches, length 32 feet 0 inches,
height 9 feet 0 inches, wing area 256 square feet.
Weights: 3727 pounds empty, 5540 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.
Sources:
-
American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday,
1982.
-
United States Military Aircraft Since 1909, Gordon Swanborough and
Peter M. Bowers, Smithsonian, 1989.
-
Curtiss Aircraft, 1907-1947, Peter M. Bowers, Naval Institute Press,
1979
- The Curtiss Shrike, Kenn C. Rust and Walter M. Jefferies, Jr., Aircraft in Profile, Doubleday, 1969.
