The Douglas SBD Dauntless was the most effective dive bomber of World War II in terms of warship tonnage sunk; U.S. Navy SBD scout-dive bombers destroyed four Imperial Japanese Navy aircraft carriers in a single day at the Battle of Midway on 4 June 1942. Dauntless dive bombers sank scores of other Japanese warships and merchant ships as well as several submarines.
The aircraft was the product of two brilliant aircraft designers, Jack Northrop and Ed Heinemann. Their XBT-1 flew for the first time in 1935. Numerous changes were made for their XBT-2 model and in flight tests that aircraft reached the then-impressive speed of 265 miles per hour. The XBT-2 designation was changed to SBD—for Scout Bombing, Douglas—and the Douglas Aircraft Company began producing them in April 1939.
The SBD was a low-wing monoplane with a distinctive canopy housing the pilot and radioman-gunner. It had large dive brakes and used a swinging “crutch” beneath the fuselage to release the bomb clear of the propeller. Unlike most contemporary carrier planes, the SBDs’ wings did not fold for shipboard storage—the last first-line U.S. carrier plane not to have folding wings until the appearance the Heinemann-designed A4D Skyhawk appeared in the 1950s. The SBD was the first carrier aircraft to have an autopilot, which was invaluable for long bombing and scouting missions. Deliveries of the SBD-1 Dauntless to the Marine Corps started in late 1940; the improved SBD-2 began entering Navy carrier squadrons the following year. In December 1941, four of the U.S. Navy’s seven aircraft carriers each embarked two SBD squadrons of 18 planes; two land- based Marine Corps squadrons also flew SBDs.
The aircraft’s baptism of fire came on 7 December 1941, during the Japanese attack on Pearl Harbor, when SBDs from the carrier Enterprise (CV-6) attempted to land on Ford Island in the center of the harbor during the raid. Several were shot down by anxious antiaircraft gunners at Pearl Harbor and two probably were lost to Japanese fighters—but SBDs may have shot down two of their antagonists in the aerial melees of that tragic day.
SBDs flew in the early air strikes in the Pacific— the first on 1 February 1942 when 36 Enterprise Dauntlesses hit Kwajalein. At the Battle of the Coral Sea in May 1942, SBDs and TBD Devastator torpedo planes sank the Japanese light carrier Shoho, while the dive bombers also damaged a large carrier (preventing the latter ship from participating in the subsequent Battle of Midway). Commander Robert E. Dixon, leading SBDs of Scouting Squadron 2 from the carrier Lexington (CV-2), radioed back to his carrier, “Scratch one flattop!” as the Shoho began to sink.
At the Battle of Midway the following month, carrier-based SBDs alone sank four large carriers—the Akagi, Kaga, Hiryu, and Soryu—and a heavy cruiser. All four of the Japanese carriers had participated in the raid on Pearl Harbor.
In the Atlantic, SBDs flew from U.S. carriers to support the North African invasion in November 1942, and in both oceans they flew from fleet carriers and escort carriers in the antisubmarine role. The SBD served as the Navy’s principal bomber aircraft until mid-1944, flying from all large carriers as well as escort or “jeep” carriers. The fleet introduction of the replacement SB2C Helldiver, which had been ordered before the war began, was delayed by teething problems. It began replacing SBDs on the larger carriers in 1944, but never achieved the popularity of the older plane; on escort carriers, the TBF/TBM Avengers replaced the SBD.
The SBD-5, the principal production variant, had a maximum speed of 252 miles per hour. Normal range was 1,100 miles in a strike role and 1,565 miles when used as a scout. The SBD bomb load, all external, was one 1,600-pound bomb under the fuselage and two small bombs or (in later aircraft) fuel tanks under the wings; a 1,000-pounder was usually carried. One or two .50-caliber machine guns were fixed in the engine cowling to fire forward and the radioman-gunner had an aft-firing .30-caliber gun, changed to a twin mount and then to .50s in later models.
The Marine Corps air arm reached a peak of 20 land-based SBD squadrons; Navy land-based units also flew the Dauntless. Through 1944, the Navy and Marine Corps took delivery of 4,923 SBDs, more than half of which were the SBD-5 variant. The U.S. Army Air Forces (AAF) procured 953 similar aircraft as the A-24. Although the AAF flew them in combat in New Guinea, their losses were heavy and dive bombing never became popular with the Army during World War II.
World War II ended on 2 September 1945 and by the end of that month the last SBD was retired from U.S. Navy-Marine service.
During the war nine SBD-5s were transferred to the Royal Air Force and Royal Navy for evaluation, but no procurement followed; New Zealand pilots did fly a number of SBDs in combat in the Pacific War. The Free French Air Force began flying the A-24B in 1943 and the French Navy received SBDs for carrier training in late 1944. Beginning on 2 April 1947, SBDs were used to strike communist targets in Indochina. Flying from the Dixmude, an American- built escort carrier, these were the first combat strikes ever flown from a French aircraft carrier.
Pilots considered the SBD a reliable and rugged aircraft. It was not very fast and had a slow rate of climb. Still, it was a highly effective dive bomber.