The Curtiss SBC Helldiver was a two-seat scout bomber and dive bomber built by the Curtiss-Wright Corporation.
It was the last military biplane procured by the United States Navy. Delivered in 1937, it became obsolete even before World War II and was kept well away from combat with Axis fighters.
There was controversy in the United States Navy’s Bureau of Aeronautics (BuAer) in the early 1930s regarding two-seat fighter planes, monoplanes and the retractable undercarriage.
In 1931, the Navy issued Design Specification No. 113, which detailed a requirement for a high-performance fighter with fixed undercarriage to be powered by the Wright R-1510 or Pratt & Whitney’s R-1535 radial engine.
Seven companies submitted proposals and two companies, the Douglas Aircraft with their XFD-1 and the Chance Vought with their XF3U-1 were given contracts for one prototype each.
Both of these aircraft were two-seat biplanes.
The Navy then asked Curtiss to supply a prototype of a two-seat monoplane which was technically more advanced.
On 30 June 1932, BuAer signed a contract with Curtiss to design a two-seat monoplane with a parasol wing a retractable undercarriage and powered by a 625 hp (466 kW) Wright R-1510-92 fourteen cylinders, two row, air-cooled radial engine driving a two-blade propeller.
This fighter was designated XF12C-1.
The SBC was an all-metal, two-seat scout-bomber biplane with “I”-type interplane struts.
It was the last combat biplane the Navy purchased, and the last combat biplane manufactured in the United States.
The two crewmen, pilot and radio operator/gunner were housed in tandem cockpits enclosed by a sliding canopy and the turtle deck behind the rear cockpit could be folded down to allow the gunner to use his machine gun.
The wings, rudder, elevators and flaps were fabric covered.
The main landing gear retracted into wheel wells in the fuselage just forward of the lower wing and the tail wheel retracted into the fuselage.
Variants
XF12C-1
Prototype parasol-wing fighter powered by a 625 hp (466 kW) R-1510-92 radial; one built, later converted into biplane as the XS4C-1.
XS4C-1
Prototype was redesignated in the “scout” category before being redesignated again as the XSBC-1.
XSBC-1
Prototype redesignated from XS4C-1, a biplane with an R-1820-80.
XSBC-2
Redesigned biplane based on XSBC-1 and powered by a 700 hp (520 kW) XR-1510-12; one built.
XSBC-3
XSBC-2 re-engined with a 750 hp (560 kW) R-1535-82.
SBC-3
Production variant with an 825 hp (615 kW) R-1534-94; 83 built.
XSBC-4
SBC-3 re-engined with a 950 hp (710 kW) R-1820-22; one conversion.
SBC-4
Production variant with a 950 hp R-1820-34; 174 built, including 50 transferred to the French Navy.
