The Curtiss O2C was the designation given to the later models of the F8C Helldiver after it was redesignated as a land based observation aircraft.
The F8C Helldiver was the first purpose-built dive bomber to be produced for the US Navy, but it only had a short service career in that role at the very start of the 1930s. When the F8C-5 ordered into production, with deliveries to start in 1931, it was seen as a land-based observation aircraft and was produced without carrier equipment. Soon after entering service the sixty three F8C-5s were redesignated as the O2C-1. Another thirty aircraft were built from new as O2C-1s, for a total of 93 aircraft.
The O2C was a biplane with staggered wings. The lower wing was straight and with an even chord. The upper wing was staggered forward, with a straight centre section and tapered outer panels. Some earlier versions of the Helldiver carried engine cowling, but that became standard equipment on the O2C. The O2C-1 was powered by the Pratt & Whitney R-1340-4 Wasp air cooled radial engine.
The O2C-1 was used by the US Marine Corps, entering service in 1931. The aircraft wasn't in front line service for long and in 1934, when 55 survived, the O2C-1 went to the Reserve.
In August-September 1930 Curtiss built two company demonstrators of a Wright Cyclone powered Helldiver. Both used the 575hp Wright R-1820 Cyclone engine and had closed cockpit canopies. The first also had a modified aft turtledeck, which was raised to fit with the canopies.
Both prototypes were bought by the Navy. The first (A8845) became the XF8C-7 and was later used as a VIP transport, carrying David S. Ingalls, Assistant Secretary of the Navy. The aircraft was later redesignated as the XO2C-2 and then as one of four O2C-2s. The modified aircraft had a top speed of 178.6mph, 30mph faster than the standard O2C-1.
The second Cyclone Helldiver (A8847) was also purchased by the Navy and became the XF8C-8. Two more aircraft were ordered at the same time (A8848 and A8849), and briefly became XF8C-8s before becoming the third and fourth O2C-2s. A8847 was later rebuilt and became the XS3C-1/ XF10C-1. One aircraft was used to test the 650hp twin-row Wright R-1510 but this aircraft caught fire in the air.
Engine: Pratt & Whitney R-1340-4
Length: 25ft 7 7/8in
Height: 10ft 3in
Empty weight: 2,520lb
Gross weight: 4,020lb
Max speed: 146mph at sea level
Climb Rate: 5.5 minutes to 5,000 ft
Service ceiling: 16,250ft
Range: 720 miles
Armament: Two fixed forward firing and one flexibly mounted .30in machine guns
Bomb load: One 500lb bomb under fuselage or two 116lb bombs under wings