The Douglas T2D “torpedo-bombing-scouting” aircraft was one of the most successful U.S. naval aircraft of the period between the World Wars. However, although designed specifically for carrier operation, the T2D apparently never flew from an aircraft carrier’s deck.1
The T2D evolved from a Navy requirement for a multi-purpose aircraft that could deliver torpedo attacks from aircraft carriers. The Bureau of Aeronautics design was issued to the Naval Aircraft Factory in Philadelphia in May 1925 for a single XTN-1, followed by a contract in June to the Douglas Company in Santa Monica, California, for three identical XT2D-1 aircraft. In the designations, the “X” indicated experimental or prototype, the “T” torpedo, the “N” Naval Aircraft Factory (NAF), and “D” Douglas. The “2” indicated the second torpedo aircraft produced by Douglas.
The NAF prototype would provide engineering standards and cost data for the Douglas firm, which would undertake series production. Donald Douglas had founded his company in 1920 to build one airplane, the Cloudster. That led to a Navy contract for a military version designated DT-1 (for Douglas Torpedo, first model). This, in turn, led to the Army Air Service’s contract for the similar Douglas World Cruisers, which made history’s first around-the-world flight in 1924 and established Douglas as an aviation byword.
The TN/T2D design was a twin-engine biplane, with manually folding wings to facilitate carrier operation. The wings, of equal span with an unstaggered configuration, were built from aluminum alloy and covered with fabric. Ailerons were fitted to both the upper and lower wings. The fuselage was built of welded chrome-molybdenum steel tube with rod bracings and fabric covering. The aircraft had a conventional tail configuration. The vertical and horizontal stabilizers were metal-covered while the elevator and rudder were fabric-covered. The aircraft was supposedly strengthened to take the anticipated stress of carrier catapult launches and arrested landings.
The plane could be provided with wheels or twin floats fitted in a manner to permit a torpedo or bombs to be carried beneath the fuselage. Thus the aircraft was convertible for operations from land, water, or carrier decks.
The crew consisted of a pilot, radio operator/gunner, and bombardier/gunner. Three (and later four) open cockpits were provided, with the pilot’s and bomb-aiming positions (with a transparent floor panel) provided forward of the wing, thus offering excellent visibility. Two .30-caliber machine guns, one fixed forward-firing and one ring-mounted flexible, were fitted. A 1,618-pound torpedo or bombs could be carried.
The Douglas project head for the T2D was a brilliant young engineer named Jack Northrop who later founded the Northrop Corporation. Another young engineer who drafted some of the T2D’s structural components was Ed Heinemann. He would also go on to an important aviation career.
Both the XTN-1 and first XT2D-1 flew in 1927, the latter soon redesignated T2D-1. The XTN-1 and first two T2D-ls were powered by Wright P2 435- horsepower engines; all subsequent aircraft had Wright R-1750 Cyclone engines, each developing 525 horsepower. Still, the aircraft were considered to be underpowered.
After its maiden flight on 27 January 1927, the first XT2D-1 was partially dissembled and shipped by the transport Argonne (AP-4) from San Diego to Hampton Roads, Virginia, and then sent up to the Naval Air Station (NAS) Anacostia in Washington, D.C., for additional flight trials. Those trials, which lasted from 18 January to 2 May 1928, revealed that
The flight performance of the XT2D- 1 is markedly superior to the performance of any similar type airplane tested by the Navy. The plane lands slowly and softly; takes off quickly and due to the twin-engine installation handles well on the ground. In the air the plane responds well to all controls.2
The Anacostia flight trials, however, also found that
The structure is fairly simple but appears to lack rigidity and ruggedness. This is based on the fact that failure of the tail skid did excessive damage to the tail of the plane, weaving of the fuselage and tail in flight and on the ground, and the fact that scarcely any shock was felt by the pilot when the right hand engine was torn out of the plane [while on the ground].3
(The senior officer of the trial board was Lieutenant Commander Arthur W. Radford, later admiral and chairman of the Joint Chiefs of Staff.)
The second and third T2Ds, after being re-engined, flew from San Diego to NAS Anacostia between 27 December 1927 and 5 January 1928—an impressive performance for the time. Also, one aircraft was hoisted by crane aboard the pioneer carrier Langley (CV-1) for handling trials as early as 1927; the plane was apparently transported aboard the Langley from San Diego to the East Coast, and back, but did not take off from the ship.
Indeed, this writer has found no record of a T2D actually operating from the Langley or, as sometimes reported, from the larger carriers Lexington (CV-2) or Saratoga (CV-3). Apparently the limited horsepower of the Wright engines and the poor structural strength prohibited carrier trials or operation. (Rather, the first known operation of a twin-engine aircraft from a carrier took place in September 1936, when the single Potez 56E light transport operated aboard the carrier Beam. The Potez 56E was the French Navy’s adaptation of a six-passenger commercial aircraft, fitted with an arresting hook for shipboard trials.)
The first T2Ds to enter service— the XTN-1 did not become operational—joined Torpedo Squadron 2 at San Diego in May 1927. Operating from ashore, the T2Ds were considered to be excellent aircraft and, in 1927, nine more T2D-ls were ordered from Douglas, a follow-on to the initial three T2Ds. Most of these aircraft—fitted with floats—flew with Patrol Squadrons 1 and 6 at Pearl Harbor until retired from service in April 1933.
Eighteen similar aircraft designated P2D-1 were ordered from Douglas in June 1930. These aircraft had twin rudders and were powered by R-1820 engines producing 575 horsepower each. The patrol designation was used for these aircraft because of objections by the Army Air Corps that land-based torpedo planes superseded the Army’s role in coastal defense operations.
Also highly popular with naval aviators, the P2Ds flew with Patrol Squadron 3F at Coco Solo in the Panama Canal Zone until replaced by PBY-1 Catalinas. The last P2D-1 was retired in February 1937. For almost a decade, the 30 Douglas T2D/P2D aircraft provided a useful patrol-reconnaissance capability for the U.S. Navy while Messrs. Northrop and Heinemann and the Douglas Company went on to produce many excellent aircraft.
1. This column is based in part on R.E. Williams, “Yesteryear...” Douglas Service magazine, November/December 1980, pp. 34-38. Also see Rene J. Francillon, McDonnell Douglas Aircraft since 1920 (London: Putnam, 1979), pp. 105-111.
2. Department of the Navy, Bureau of Aeronautics, “Report on XT2D-1 Douglas Twin Engine Bomber (Land Type),” 22 May 1928, p. 8.
3. Department of the Navy, “Report on XT2D-1...”, p. 9.