Douglas SBD Dauntless

The Douglas SBD Dauntless is a World War II American naval scout plane and dive bomber that was manufactured by Douglas Aircraft from 1940 through 1944. The SBD ("Scout Bomber Douglas") was the United States Navy's main carrier-based scout/dive bomber from mid-1940 through mid-1944. The SBD was also flown by the United States Marine Corps, both from land air bases and aircraft carriers. The SBD is best remembered as the bomber that delivered the fatal blows to the Japanese carriers at the Battle of Midway in June 1942. The type earned its nickname "Slow But Deadly" (from its SBD initials) during this period. Even though the SBD was ostensibly replaced by the Curtiss SB2C Helldiver in 1944, experience showed the earlier plane performed better, and both models fought side-by-side until the end of the war.

During its combat service, the SBD proved to be an effective naval scout plane and dive bomber. It possessed long range, good handling characteristics, maneuverability, potent bomb load, and great diving characteristics from the perforated dive brakes. A land-based variant of the SBD – omitting the arrestor hook — was purpose-built for the U.S. Army Air Forces, as the A-24 Banshee. Due to lack of specialized training, though, the Army's experience was not as successful, and by the middle of 1943, the A-24 was considered by pilots to be too vulnerable for service, owing to its armament and slow speed, and was relegated to noncombat roles.

Design and development

thumb|Comparison of the XBT-1 and XBT-2 (SBD)

Design work on the Northrop BT-1 began in 1935. In 1937, the Northrop Corporation was taken over by Douglas, and the active Northrop projects continued under Douglas Aircraft Corporation. The Northrop BT-2 was developed from the BT-1 by modifications ordered in November 1937, and provided the basis of the SBD, which first entered service in mid-1939. Ed Heinemann led a team of designers who considered a development with a Wright Cyclone engine. The plane was developed at the Douglas El Segundo, California, plant, and that facility, along with the company's Oklahoma City plant, built almost all the SBDs produced. Unusual for carrier aircraft, folding wings were not chosen for the design, opting instead for structural strength.

thumb|A [[U.S. Navy SBD releasing a bomb. The perforated surfaces deflected on the trailing edge of the wing are dive brakes]]

The next version was the SBD-3, which began manufacture in early 1941. It had increased armor, self-sealing fuel tanks, and four machine guns. The SBD-4 provided a 12-volt (up from 6-volt) electrical system and a few were converted into SBD-4P reconnaissance aircraft.

The next (and most produced) version, the SBD-5, was produced mostly in the Douglas plant in Tulsa, Oklahoma. This version was equipped with a engine and an increased ammunition supply. Over 2,400 of these were built. A few of them were shipped to the Royal Navy for evaluation. In addition to American service, the SBD saw combat against the Japanese Army and Navy with No. 25 Squadron of the Royal New Zealand Air Force, but the RNZAF soon replaced them with the larger, faster, heavier. and land-based Vought F4U Corsairs.

Some SBDs were also flown by the Free French Air Force against the German Heer and Luftwaffe. SBDs were also sold to Mexico.

The final version, the SBD-6, had more improvements, but its production ended during the summer of 1944.

The U.S. Army Air Forces (USAAF) had its own version of the SBD, called the A-24 Banshee. It lacked the tail hook used for carrier landings and a pneumatic tire replaced the solid tail wheel. First assigned to the 27th Bombardment Group (Light) at Hunter Field, Georgia, A-24s flew in the Louisiana maneuvers of September 1941. The three versions of the Banshee (A-24, A-24A and A-24B) were flown by the USAAF to a very minor degree in the early stages of the war. The USAAF used 948 of the 5,937 Dauntlesses built.

Operational history

U.S. Navy and Marine Corps

thumb|left|Damaged VB-6 SBD-3 on after the attack on at [[Battle of Midway|Midway]]

U.S. Navy and Marine Corps SBDs saw their first action at Pearl Harbor, when most of the Marine Corps SBDs of Marine Scout Bombing Squadron 232 (VMSB-232) were destroyed on the ground at Ewa Mooring Mast Field. Most U.S. Navy SBDs flew from their aircraft carriers, which did not operate in close cooperation with the rest of the fleet. Most Navy SBDs at Pearl Harbor, like their Marine Corps counterparts, were destroyed on the ground. On 10 December 1941, SBDs from sank the Japanese submarine I-70. In February–March 1942, SBDs from the carriers , , and , took part in various raids on Japanese installations in the Gilbert Islands, the Marshall Islands, New Guinea, Rabaul, Wake Island, and Marcus Island.

The first major use of the SBD in combat was at the Battle of the Coral Sea, where SBDs and TBD Devastators sank the Japanese light aircraft carrier (CVL) and damaged the Japanese fleet carrier . SBDs were also used for antitorpedo combat air patrols,  and these scored several victories against Japanese aircraft trying to attack Lexington and Yorktown. Their relatively heavy gun armament with two forward-firing .50 BMG| M2 Browning machine guns and either one or two rear flexible-mount .30-06 Springfield| AN/M2 machine guns was effective against the lightly built Japanese fighters, and many pilots and gunners took aggressive attitudes to the fighters that attacked them. SBD pilot Stanley "Swede" Vejtasa was attacked by three A6M2 Zero fighters; he shot down two of them and cut off the wing of the third in a head-on pass with his wingtip.