Douglas TBD Devastator
Design & Development

Ordered on 30 June 1934, and entered into a U.S. Navy competition for new bomber aircraft to operate from its aircraft carriers, the Douglas entry was one of the winners of the competition. Other aircraft ordered for production as a result of the competition included the Northrop BT-1 which would evolve into the SBD Dauntless, the Brewster SBA and the Vought SB2U Vindicator.

Douglas TBD Devastator
Douglas TBD-1 Torpedo Planes, of Torpedo Squadron Five (VT-5), parked on the after flight deck of
USS Yorktown (CV-5) at Naval Air Station, North Island, San Diego, California, in June 1940. Three of these aircraft are painted in an experimental color scheme used during Fleet Problem XXI.

[Source: U.S. Naval Historical Center]

The XTBD Devastator, which flew for the first time on 15 April 1935, marked a large number of "firsts" for the U.S. Navy. It was the first widely-used carrier-based monoplane as well as the first all-metal naval aircraft, the first with a totally-enclosed cockpit, the first with power-actuated (hydraulically) folding wings; it is fair to say that the TBD was revolutionary. A semi-retractable undercarriage was fitted, with the wheels designed to protrude 10 in (250 mm) below the wings to permit a "wheels-up" landing with only minimal damage. A crew of three was normally carried beneath a large "greenhouse" canopy almost half the length of the aircraft. The pilot sat up front; a rear gunner/radio operator took the rearmost seat, while the bombardier occupied the middle seat. During a bombing run, the bombardier lay prone, sliding into position under the pilot to sight through a window in the bottom of the fuselage, using the Norden Bombsight.

The normal TBD offensive armament consisted of either a 1,200 lb (540 kg) Bliss-Leavitt Mark 13 aerial torpedo or a 1,000 lb (450 kg) bomb. Alternatively, three 500 lb (230 kg) general-purpose bombs: one under each wing and one under the fuselage, or 12 100 lb (45 kg) fragmentation bombs: six under each wing, could be carried. This weapons load was often used when attacking Japanese targets on the Gilbert and Marshall Islands in 1942. Defensive armament consisted of a .30 in (7.62 mm) machine gun for the rear gunner. Fitted in the starboard side of the cowling was either a .30 in (7.62 mm) or .50 in (12.7 mm) machine gun.

The powerplant was a Pratt & Whitney R-1830-64 Twin Wasp radial engine of 850 hp (630 kW), an outgrowth of the prototype's Pratt & Whitney XR-1830-60/R-1830-1 of 800 hp (600 kW). Other changes from the 1935 prototype included a revised engine cowling and raising the cockpit canopy to improve visibility.

The XTBD had a flat canopy that was replaced on production models by a higher, domed canopy over a roll over bar. Other than requests by test pilots to improve pilot visibility, the prototype easily passed its acceptance trials that took place from 24 April-24 November 1935 at NAS Anacostia and Norfolk bases. After successfully completing torpedo drop tests, the prototype was transferred to the Lexington for carrier certification. The extended service trials continued until 1937 with the first two production aircraft retained by the company exclusively for testing.

A total of 129 of the type were purchased by the U.S. Navy's Bureau of Aeronautics (BuAer), and starting from 1937, began to equip the carriers Saratoga, Enterprise, Lexington, Wasp, Hornet, Yorktown and Ranger. In pre-war use, TBD units were engaged in training and other operational activities and were gradually approaching the end of their useful service life with at least one aircraft being converted to target tug duty. By 1940, the U.S. Navy was aware that the TBD had become outclassed by the fighters and bombers of other nations and a replacement was in the works, but it was not yet in service when the U.S. entered World War II. By then, attrition had reduced their numbers to just over 100 aircraft. The U.S. Navy assigned popular names to its aircraft in late 1941, and the TBD became the Devastator, although its nickname "torpecker" was commonly used.