The XA-8 won a competition against the General Aviation/Fokker XA-7, after which 13 service test aircraft were ordered (five as YA-8s and eight as Y1A-8s). After the completion of testing, 11 of these aircraft were redesignated A-8.
The A-8 was the first Curtiss machine of all-metal low-wing monoplane configuration with advanced features such as automatic leading edge slats and trailing-edge flaps.
Four forward-firing .30 in (7.62 mm) machine guns were mounted in the wheel fairings, and an additional weapon of the same calibre was fitted in the observer's cockpit for rear defense. The standard bomb load was four 100 lb (45 kg) bombs.
One YA-8 was fitted with a radial engine and designated YA-10, while another was used for testing of the Curtiss V-1570 Conqueror engine as the Y1A-8A. This aircraft was redesignated A-8 upon the completion of testing.
46 aircraft were ordered as A-8Bs, however the order was changed to the Model 60 A-12s before production began.
Length: 32 ft 0 in (9.76 m)
Wingspan: 44 ft 0 in (13.41 m)
Height: 9 ft 0 in (2.74 m)
Wing area: 256 sq ft (23.78 m²)
Empty weight: 3,910 lb (1,777 kg)
Loaded weight: 5,888 lb (2,676 kg)
Powerplant: 1 × Curtiss V-1570-31 Conqueror Vee, 600 hp (447 kW)
Maximum speed: 183 mph (159 knots, 295 km/h)
Cruise speed: 153 mph (133 knots, 246 km/h)
Range: 480 mi (417 nmi, 773 km)
Service ceiling: 18,100 ft (5,500 m)
Rate of climb: 1,325 ft/min (6.7 m/s)
4 × forward-firing 0.3 in (7.62 mm) M1919 Browning machine guns were mounted in the wheel fairings
1 × 0.3 in (7.62 mm) machine gun mounted in the observer's cockpit for rear defense
Bombs: Up to 4 × 100 lb (45 kg) bombs carried under the wings or up to 10 × 30 lb (13.6 kg) fragmentation bombs in fuselage chutes either side of the main fuel tank