The Douglas SBD Dauntless was the U.S. Navy's main scout bomber and dive bomber from mid-1940 until 1943, when it was replaced by the SB2C Helldiver. Commonly, their extremely effective dive bombing technique was known as "Helldiving", leading to their being nicknamed "Helldivers" (not to be confused with other aircraft officially designated the Helldiver, like the SB2C listed above).

The Northrop BT-1 provided the basis for the design of the SBD, which began manufacture in 1940. It was designed with a 1,000 horsepower Wright Cyclone powerplant. A year earlier, both the U.S. Navy and Marine Corps had placed orders for the new dive bombers, aptly designated the SBD-1 and SBD-2 (the latter had increased fuel capacity and different armament). The former went to the Marine Corps in late 1940, and the latter went to the Navy in early 1941.

The next version, titled the SBD-3, began manufacture in early 1941. It provided increased protection, self-sealing fuel tanks, and four machine guns. The SBD-4 provided a 12-volt (from 6) electrical system, and a few were converted onto reconnaissance platforms.

The next (and most produced) variant, known as the SBD-5, was primarily produced on Douglas's plant at Tulsa, Oklahoma. It was equipped with a 1,200 hp (895 kW) engine and increased ammunition. Over 2,400 were built, and a few were shipped to the Royal Navy (although they were not used operationally). A few were also sent to Mexico. The final version, the SBD-6, provided many improvements, but came later and was not used as much.

The U.S. Army made its own version of the SBD, known as the A-24, which was essentially the same aircraft with a few changes (the removal of the unnecessary arresting hook and different tires). Two versions (the A-24A and A-24B) were produced and used by the Army through and after the war.

History

It was first majorly used during the Battle of the Coral Sea, when SBDs and TBDs sank the Japanese aircraft carrier Shoho. However, its most important contribution to the American war effort probably came during the Battle of Midway (early June 1942), when it sank four of the Japanese heavy carriers (the Akagi, Kaga, Soryu, and Hiryu), also heavily damaging two Japanese cruisers (the Mikuma and the Mogami, one of which was later scuttled by a Japanese destroyer).

SBD Dauntless

However, they were not utilized to the best of their ability. One squadron of Marine SBDs, operating off Midway Island, was not yet trained in the effective "Helldiving" technique; instead, they were forced to use the slower but easier glide bombing technique, which led to that squadron's almost total destruction. The carrier-borne squadrons, on the other hand, were much more effective, combined with their F4F Wildcat fighter escorts.

Next, SBDs participated in the Guadalcanal Campaign, both from American carriers and Henderson Field on Guadalcanal Island. It contributed to the heavy loss of Japanese shipping during the campaign. Dauntlesses eventually sank the Japanese carrier Ryujo near the Solomon Islands (in late 1942), damaging three others. They proceeded to sink one cruiser and nine transports during the decisive Battle of Guadalcanal.

During this decisive time of the Pacific Campaign, the SBD's strengths and weaknesses became evident. Interestingly, while the American strength was dive bombing, the Japanese preferred their Nakajima B5N "Kate" torpedo bombers, which caused the bulk of the damage at Pearl Harbor. Finally, the Dauntless was also very steady while diving.

In 1944, the Dauntless undertook its last major action during the Battle of the Philippine Sea, although the Marines utilized them until the end of the war (in 1945). It had already been replaced by the SB2C Helldiver in the U.S. Navy. The Dauntless was one of the most important aircraft in the Pacific Theatre of World War II, with dozens of ships sunk or heavily damaged by Dauntlesses.

Sources

• Warbird Alley: SBD (http://www.warbirdalley.com/sbd.htm)
• The SBD Shipborne Dive Bomber (http://www.compass.dircon.co.uk/SBD.htm)
• Aero-Web.org: SBD-5 Dauntless (http://www.aero-web.org/specs/douglas/sbd-5.htm)