The Curtiss SBC Helldiver holds two places in naval aviation history: First, it initially flew as a monoplane but was produced as a biplane, and, second, it was the last biplane combat aircraft procured by the United States.1 While not unique, the SBC also had one of the most convoluted development histories of a military aircraft.
Curtiss—a leader in aircraft development for the Army and Navy in the 1920s and 1930s—produced a prototype monoplane two-seat fighter for the Navy in 1932 with the designation XF12C-1. The aircraft was in part a “navalized” version of the Army’s O-40 Raven reconnaissance plane, featuring a high-mounted parasol wing and fully retractable landing gear. The structure was all metal except for fabric covering the movable control surfaces and the flaps. And, being intended for carrier operation, the naval aircraft had a strengthened fuselage, backward-folding wings, and arresting hook.2
The single XF12C-1 first flew in July 1933. The Navy Department then decided to employ it as a scouting plane and changed its designation to XS4C-1 in December 1933. The Navy soon changed the aircraft’s role to that of a scout-bomber and, with a more powerful engine, the prototype became the XSBC-1 in January 1934.3 The flight tests revealed a structural failure in the parasol wing during dives, with the aircraft crashing in September 1934. (The Curtiss test pilot parachuted to safety.)
A new prototype was ordered as a biplane with an upgraded engine. This plane made its first flight as the XSBC-2 on 9 December 1935. It was in several respects a wholly new design—but retained the same Navy serial number—9225! It had a fuselage and tail surfaces of metal monocoque construction with metal-frame wings and coverings of metal skin and fabric. Still another engine change led to the aircraft becoming the XSBC-3. The Navy was so pleased with this variant that 83 planes were ordered with the designation SBC-3. Deliveries to the fleet began in July 1937, with Scouting Squadron (VS)5 receiving the first production aircraft.
A late-production plane was provided with a still more powerful engine and flew as the XSBC-4. This became the definitive Helldiver—the Curtiss-assigned name—and 174 production models followed. The U.S. Navy accepted the first SBC-4 in March 1939.
Because of the deteriorating situation in Europe, in 1939 the French government ordered 90 of these aircraft from Curtiss. They were identical to the Navy’s SBC-4s except for the provision of self-sealing fuel tanks. After hostilities began in Europe in September 1939, the Navy was directed to divert 50 SBC-4s to the French. These aircraft, mostly taken from U.S. Naval Reserve units, were flown to the Curtiss plant in Buffalo, New York, where they were modified for French service, being fitted with .50-caliber machine guns, painted in camouflage colors, etc.
American neutrality laws prevented weapons—including combat aircraft—from being transferred to countries at war. Accordingly, the reserve pilots were “converted” to Curtiss employees and flew the planes from the Buffalo plant to Houlton, Maine. The aircraft were then towed across the Canadian border to take off from a pasture in New Brunswick for the brief flight to Dartmouth on Halifax Harbor. One aircraft crashed; its pilot was killed. Curtiss paid each pilot $250 for the flight plus return rail fare from Dartmouth to Buffalo, where the fliers were returned to Naval Reserve status.
At Dartmouth 44 of the surviving 49 SBC-4s were loaded aboard the French aircraft carrier Béarn for shipment to Europe. (Fifty-eight other aircraft types also were embarked in the ship.) In June 1940, before the Béarn could reach her destination, the French government capitulated to the Germans. The carrier then was diverted to the Caribbean island of Martinique, where she was interned at U.S. direction to prevent a possible takeover by the pro-German Vichy French regime. The carrier’s aircraft were unloaded and were destroyed by heat, humidity, and pilfering.4
The five French aircraft that were not taken aboard the Béarn eventually reached England. The Royal Air Force found them unsuitable for combat and—assigned the name Cleveland—they were employed as ground trainers.
The U.S. Navy’s shortfall in Helldivers transferred to the French was made up by taking on 50 of the aircraft from the Curtiss production line that were being built for the French. Several Navy scouting (VS) and bombing (VB) squadrons flew Helldivers. But the biplane SBC quickly was outdated as newer scout-bombers were delivered, the Vought SB2U Vindicator and, especially, the Douglas SBD Dauntless. At the time of U.S. entry into World War II in December 1941 there were 69 SBC-3 and 117 SBC-4 aircraft in Navy and Marine service.
The USS Hornet (CV-8) was the last aircraft carrier to operate SBCs, and in late 1941 her VB-8 and VS-8 squadrons were trading in their SBC-4 Helldivers for SBD Dauntlesses. Marine Observation Squadron (VMO)151 at Quantico had 11 SBC-4 aircraft when the war began; it is believed to have been the only active squadron with the aircraft. Navy and Marine detachments, reserve units, and Navy and Marine command headquarters still operated large numbers of SBCs when the United States went to war.
When the conflict began, VMO-151 was rushed to the West Coast to fly antisubmarine patrols out of San Diego and Long Beach, seeking purported Japanese submarines. No hostile craft were sighted. Sent back to the East Coast, by March the squadron’s 22 aircraft were being loaded aboard ship to be sent to the Pacific war. (At the time the squadron had 27 pilots—3 experienced in SBCs, 17 fresh from flight school, and 6 trained in fighters.)
VMO-151 was shipped to Samoa in April–May 1942 as part of the Marine contingent provided to defend the area against possible Japanese incursions. The squadron personnel and those of other components of Marine Aircraft Group (MAG)13 lived in primitive conditions on Samoa. The squadron immediately began flying antisubmarine patrols—each SBC carrying a single depth charge—and, again, seeing no hostile undersea craft.5
The scout-bomber unit was redesignated VMSB-151 in September 1942 and a month later gave birth to the spin-off squadron VMO-155, initially flying ten SBC-4 aircraft. By the end of the year SBD-4 Dauntless dive bombers were replacing the SBCs and all of VMSB-151’s outdated Helldivers were gone by June 1943. VMO-155 initially flew SBCs and F4F-3P Wildcat photo planes, the latter from the escort carrier Nassau (CVE-16). VMO-155 was changed to Fighter Squadron 155 in January 1945.
Apparently the U.S. SBCs had never fired a shot in anger.
The next Curtiss-developed Helldiver was the SB2C. This aircraft had major teething problems, but soon was established as a valid component of U.S. carrier air groups, saw extensive combat in the Pacific war, and flew in several foreign air force markings.6
1. The author appreciates the assistance provided by CDR Peter B. Mersky, USNR (Ret.), in preparing this column.
2. Descriptions of these aircraft are found in Peter M. Bowers, Curtiss Aircraft 1907–1947 (Annapolis, MD: Naval Institute Press, 1979), 345–47, 368–73.
3. The combined category of scout bomber was established in 1934.
4. In 1944 the Béarn was sailed to the New York Navy Yard where she was rehabilitated, modernized, and configured for use as an aircraft transport. She returned to French naval service in 1945 and served primarily as an aircraft transport until 1948, and then as a submarine depot ship, finally being stricken in 1966 and scrapped.
5. Col. J. B. Berteling, USMC (Ret.), “Flying to World War II in a Biplane,” Foundation, Fall 1995, 41–45.
6. Norman Polmar, “The Ultimate Helldiver,” Naval History, vol. 15, no. 6 (December 2001), 12.
Curtiss SBC-4 Helldiver
Type: Scout bomber
Crew: Pilot, radioman-gunner
Gross weight: 7,632 pounds
Engine: 1 Wright R-1820-34 radial; 850 horsepower
Length: 28 feet, 2 inches
Wingspan: 34 feet
Wing area: 317 square feet
Height: 10 feet, 5 inches
Max. speed: 234 mph at 15,200 feet
Cruise 175 mph
Range: 400 miles with 500-pound bomb
Ceiling: 24,000 feet
Armament: 1 .30-caliber machine gun fixed forward-firing
1 .30-caliber machine gun rear swivel mount
1 500- or 1,000-pound bomb