Curtiss A-25/SB2C Helldiver
By Joe Baugher
Following the success of Ju.87 Stukas in the German attack on Poland in 1939 and in the offensive in the west in the spring of 1940, the US Army developed a sudden interest in dive bombers. Up to that time, the Navy and the Marine Corps had been the only American armed services interested in dive bombers and had, in fact, done some pioneering work which had been one of the inspirations behind the German development of the Stuka.
In pursuit of this new interest, the Army decided to acquire some Navy designs and use them with very little modification as land-based dive bombers. One of these designs was the Curtiss SB2C Helldiver, which the Army acquired under the designation A-25.
Development of the SB2C began in 1938 when the Navy laid down requirements for a new scout/dive bomber aircraft. In Aug 1938, an invitation was sent out to the aircraft industry calling for a new dive bomber powered by an air-cooled radial engine. It was to be equipped with folding monoplane wings, retractable landing gear, de-icing equipment, heavy armament, and armor protection for the crew. Six companies submitted proposals, with the Curtiss and Brewster designs showing the greatest promise, both powered by the 1700hp Wright R-2600. In Jan 1939, both companies were selected to build prototypes of their designs under the designation XSB2A-1 and XSB2C-1, respectively.
XSB2C-1 was a monoplane with wings mounted up high enough on the fuselage to permit the installation of an internal bomb bay. The main landing gear retracted inwards, and the wing training edge had split dive flaps. The plane was all-metal except for fabric-covered control surfaces. The crew was twoa pilot sitting under a rearward-sliding canopy and a gunner under a separate forward-sliding canopy. The rear fuselage arrangement was quite similar to that of the earlier SBC biplane dive bomber.
The XSB2C-1 prototype flew for the first time on Dec 8, 1940, with Curtiss test pilot Lloyd Childs at the controls. It crashed on Dec 21, 1941, after the wings and tail failed while trying to pull out of a divethe pilot parachuted to safety.
On Oct 1, 1941, the Navy decided to give its combat aircraft names, and SB2C was assigned Helldiver, a name long associated with Curtiss naval dive bombers.
Following Pearl Harbor, the Helldiver program took on a new urgency. The first 4 SB2C-1s were assigned special priority so that flight testing could get underway as soon as possible. In the spring, the Navy announced that 3000 additional Helldivers would be ordered from Curtiss. In May, 1000 Helldivers were ordered from Canadian Car and Foundry at Fort William, Ontario. These were assigned the designation SBW, and 450 of them were allocated to the Royal Navy.
The first production SB2C-1 was rolled out in June. It was quite similar to the XSB2C-1 with the exception of a slightly taller vertical tail. It flew for the first time on June 30, 1942.
In 1940 procurement of dive bombers was included in the USAAC expansion program. Rather than develop new aircraft from scratch, the Army turned to the Navy's Douglas SBD Dauntless and Curtiss SB2C Helldiver to fill this need. In late 1940, agreement was reached for the Army to get approximately 100 SB2Cs from Curtiss under the recently-signed Navy contract. These planes were referred to as SB2C-1A for contract purposes, but were designated A-25A by the Army. A-25A was to be standardized to the extent possible with the SB2C-1. An order for 100 A-25As was added to the Navy contract on Dec 31, 1940.
By the end of 1941 much larger orders for A-25As were being considered, but the Navy felt that all the production capacity of Curtiss-Wright's Columbus OH plant would be required to meet its needs. Consequently, the Army Air Materiel Command directed that C-W's St Louis plant be turned over to A-25A production. By the spring, 3,000 more A-25As were on order.
A-25A was to be almost identical to the SB2C-1, but with larger main wheels and a larger pneumatic tail wheel. The carrier arrester gear was deleted, but the folding wings were to be retained. In addition, Army radios and additional forward and underside armor plating were fitted. Both Navy and Army models had larger wheel wells to maintain standardization. Armament consisted of two 500# bombs on wing racks and two 1000# bombs in the internal bomb bay. Four fixed, forward-firing .50-inch machine guns were in the wings, and one .50-inch flexibleo gun was used by gunner. Alternatively, the underwing bombs could be replaced by a pair of 58-gallon drop tanks.
Major subcontractors and suppliers for the Navy production were retained for the A-25A in order to enhance standardization; however, there were problems involved in coordinating engineering and manufacturing between Columbus and St Louis. Those snags were not eased by the fact that the two plants were divisions of the same company. Enough differences between the A-25A and the SB2C-1 evolved so that the A-25A got its own model number of S84 within the Curtiss organization and its own series of drawings.
The A-25A made its first flight on Sep 29, 1942, about three months after the initial flight of the first production SB2C-1. It had the folding wings and the wing slats of the SB2C-1. Production and testing preceded rather slowly, and the first 10 production examples were not completed until Mar 1943. They were destined to be the last A-25As with folding wings. By this time, it was deemed impractical to continue the attempt to maintain standardization between the A-25A and the SB2C-1, since that was holding up both programs. It was decided to transfer the A-25A program over to an Army contract. That transition added further to delays in the A-25A program, due to problems with inspection authority, government furnished equipment, and coordination with subcontractors.
By the time that A-25A production was underway, the Army had found that it no longer had any need for dive bombers. Army pilots had not been well trained in dive-bombing techniques, and their combat experience with the A-24 (Army version of the SBD Dauntless) was less than happy. A-24 suffered heavy losses from enemy flak and could not be operated in environments in which less than complete air superiority had been established. Consequently, the A-25As that were delivered to the Army were assigned to various second-line activities such as training and target-towing, and never saw any combat. The Army initially assigned the popular name Shrike to the A-25A, as having been associated with Curtiss-built Army attack planes since the A-8/A-10 series back in the early '30s. However, by the end of 1943, the Army adopted the Navy Helldiver. By then, the Army's A-25As had been redesignated RA-25Athe R prefix for "Restricted," not to be used in combat.
Early in the A-25A program, 150 aircraft had been allocated to the Royal Australian Air Force [A69-1/-150]. However, RAAF came to the same conclusion as USAAF, namely, that it really did not need dive bombers, and only 10 were actually delivered [A69-1/-10]. 410 A-25As (including 140 originally intended for RAAF) were eventually turned over to the USMC for use as land-based dive bombers under the designation SB2C-1A. Following a configuration review for the Marines, a program was set up to send the transferred planes through modification centers operated by NAF Roosevelt Field, Consolidated-Vultee, and Delta Airlines. SB2C-1As were then issued to Marine Corps VMSB squadrons for operational training. By the end of 1944, all SB2C-1As had been modified and delivered. Transfer to the Navy's Operational Training Command had begun. They served with VMSB-132, -144, -234, -344, -454, -464, -474, and -484. In the autumn of 1944, the first three became VMTB squadrons and the fourth was disbanded. VMSB-454 became a VMTB squadron in the same period. The last three units were replacement training squadrons based at MCAS El Toro CA. The Navy/USMC SB2C-1As were also destined for a non-combat role, and both Army and USMC land-based Helldivers were declared surplus at an early date.
USAAF A-25A Serials:
41-18774/18783 Curtiss A-25A-1-CS
41-18784/18823 Curtiss A-25A-5-CS
41-18824/18873 Curtiss A-25A-10-CS
42-79663/79672 Curtiss A-25A-10-CS
42-79673/79732 Curtiss A-25A-15-CS
42-79733/79972 Curtiss A-25A-20-CS
42-79933/80132 Curtiss A-25A-25-CS
42-80133/80462 Curtiss A-25A-30-CS