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Curtiss A-18 (Shrike II)

1936 GOLDEN AGE WORLD WAR 2

History

In the mid-1930s, the United States Army Air Corps (USAAC) began evaluating a new twin-engine, two-seat ground attack aircraft as part of the Curtiss XA-14 program. The design provided a very modern look as well as superior performance for the time, the latter qualities of which allowed the aircraft to outperform even some of the fastest fighter jets of the time. A test article was completed, which led to the development of the designation Y1A-18 and the final designation A-18 "Shrike".

However, total production only reached 13, as the A-18 family was even surpassed by newer designs - the A-18 never became a long-term solution for USAAC as it was quickly replaced by more advanced forms.

The tactical value of ground attack aircraft to war planners beginning World War II (1939-1945) steadily increased. These platforms provide roughly the same firepower as medium-range bombers, but can also be used as direct-attack heavy fighters.

This flexibility was in high demand in aviation service at the time, and the A-18 seemed a perfect fit for USAAC as it retrofitted its inventory of older aircraft. The service evaluated a small selection of twin-engine, two-seater types before the war.

Derived from the original Curtiss Type 76, the A-18 was powered by a pair of Wright XR-1510 "Cyclone" radial piston engines, each rated at 600 hp, with two-bladed propellers. A single-wing design was chosen, with the engines housed in a streamlined nacelle along the leading edge of the wing. Wings and engines spanned the slender fuselage, with improved aerodynamics.

Two crew members sit under a relatively long frame canopy. The rear wing is a traditional layout with a single vertical rear wing and a low-set horizontal plane. The landing gear has a typical trailing configuration.

Following testing of the Type 76, the aircraft was redesigned with Wright R-1670-5 "Cyclone" engines rated at 775 hp (each) and "constant speed" propellers for improved performance. Testing resumed, always producing slightly more advanced models to test engines and weapons (including installing Wright R-1820-47 "Cyclone" radials, each rated at 850 hp and three-bladed propellers; also tested up to 37 mm gun caliber).

Before closing, the design became the Type 76A ("Shrike II"), which was the basis for the final A-18 service-test form that appeared in 1936.

A-18s were delivered to 8th Assault Squadron, 3rd Assault Group (Barksdale Field, LA) July-October 1937, which soon adopted the aircraft as an effective firing and bombing platform (Bombs are housed in compartments. In each wing assembly). The A-18 was then used for training in the 1940s.

Despite this performance, there are several weaknesses in their design that become apparent in operational use. Their landing gear had a tendency to collapse during landing or takeoff, and their engines caused the aircraft to underpower, which in turn limited its bomb-loading capacity. To further limit the scope of her future service to USAAC, the design was an expensive investment at approximately $105,000 per unit.

Curtiss tried to fix some of their issues, including supplying the product with Wright R-1830 Radial Radiation, but the damage was done.

Despite the initial potential of the A-18, the A-18 proved to have a useful lifespan when the 8th Assault Squadron took over the updated Douglas A-20 Havoc (detailed elsewhere on this site) from 1941 very short. There has also been little foreign interest in buying the aircraft, whose design originated in the mid-1930s hindering pretty much any future for the A-18. The few remaining A-18s flew in 1942, but the line was completely phased out in 1943.

Neither saw combat action in World War II, but two fought through the 108th Reconnaissance Squadron over the Panama Canal Zone, where they spent their final days in the skies.

The A-18 proved helpful to USAAC observers as the value of a larger, heavier twin-engine multi-crew system was realized. The A-20 and Martin A-26 "Invaders" became some of the more classic forms of this class of aircraft used in World War II.