05/31/2018. Remarks by Johan Visschedijk: "Shortly after the chief of the USN's Bureau of Construction and Repairs Aircraft Division, Commander Hunsaker, learned that Donald Douglas, his former assistant at MIT, had moved to the West Coast, Hunsaker hinted in a letter to him that he hoped the Navy would help develop the aviation facilities on the Pacific Coast. Little did he know that less than ten months later his friend would submit on behalf of the Davis-Douglas Company the specification for a new type of single-engined torpedo seaplane. From this specification dated February 1, 1921, would evolve the first Douglas production type, forging a strong relationship between Douglas and the USN which has remained unbroken for almost a century.

The aircraft proposed by Douglas in February 1921 was similar to the Cloudster but, whereas the first Douglas had an all-wood structure, the torpedo-bomber was of mixed construction. Built in three sections, the fuselage was of welded steel with aluminum covering on the forward and center sections and fabric covering on the rear section, and the horizontal tail surfaces were also of welded steel with fabric covering. Wooden structure with fabric covering was used for the vertical surfaces and the wings which, for shipboard storage, could be folded horizontally alongside the fuselage. As originally proposed, the aircraft was a single-seater with the pilot in an open cockpit in the center section of the fuselage behind the wing trailing edge. Twin wooden floats were to be fitted for operations from water and a 1,835 lb (832 kg) torpedo could be carried in a recess beneath the fuselage.

After completing the plans for his torpedo-bomber, Donald Douglas went to Washington where he submitted his proposal to the Bureau of Construction and Repairs of the USN. At that time the Navy wanted to test several types of torpedo-carrying aircraft before signing production contracts. Prototypes of the Curtiss CT-1, Stout ST-1, Fokker FT-1 and Blackburn BST-1 Swift were ordered for competitive evaluation whilst on April 14, 1921, the Davis-Douglas Company was awarded Contract No. 53305, its first military contract. The company was contracted to build and test three experimental aircraft designated DT-1s and to supply complete engineering information as well as three sets of wheel landing gears for operation from shore bases or aboard aircraft carriers.

Built in the Goodyear airship hangar in East Los Angeles, the first aircraft (c/n 101, BuNo A-6031) was completed as a single-seater in October 1921 and was powered by a standard 400 hp Liberty liquid-cooled engine enclosed in a cowling of rectangular cross-section with radiators attached externally to the firewall on each side of the fuselage. At the time of its completion the DT-1 was fitted with twin floats but for its test flight had a land landing gear and was tested by Eric Springer from Goodyear Field in early November 1921. On the 10th of the same month, Springer flew the aircraft to the NAS San Diego, where it satisfactorily completed its acceptance trials, with both wheels and floats, in mid-December 1921.

Successful as it was, the DT-1 did not fully satisfy naval aviators, who felt that torpedo-bombers should carry a crew of two or three. Accordingly, the Douglas Company received instructions to modify the second and third aircraft (A-6032 and A-6033) as two-seaters. To accommodate an observer/gunner, the pilot's cockpit was moved forward to a position immediately beneath the upper wings whilst the second crew member, who manned a flexible 0.30 in (7.62 mm) machine gun, sat in a separate cockpit behind the trailing edge of the wings.

For a while it seemed that the future of the Douglas torpedo-bomber was in jeopardy because on March 8, 1922, by which time it had been flown for a total of 22 hr 25 min, the DT-1 struck the water and nosed over during a high-speed flight over San Diego Bay. The remaining two prototypes were modified and re-designated DT-2s, the first of which was destroyed in a landing accident on July 19, 1922, at NAS Anacostia, Washington, D.C., after being tested for a total of only 6 hr 23 min. Fortunately for Douglas, the third aircraft, which had made its maiden flight on April 18, 1922, and had been ferried to San Diego four days later, fared better as it successfully completed its final Board of Inspection and Survey (BIS) trials and served briefly with Torpedo Squadron One (VT-1) before being struck off the Navy List.

This third aircraft (A-6033) had a modified engine installation with the two external water-cooling units of the DT-1 replaced by a nose radiator mounted within the engine cowling. It had originally been fitted for factory trials with a standard 400 hp Liberty engine; however, to offset the heavier weight of the two-seat DT-2, it had been decided to fit a higher compression 450 hp Liberty engine and this was installed in San Diego before beginning preliminary Service trials. With this engine, however, oil cooling problems were experienced and the Navy returned the aircraft to have a modified oil radiator mounted externally over the left hand walk-way. Further tests were then made in Los Angeles and San Diego until finally the aircraft was transferred to NAS Anacostia, where it was received in October 1922 and where full BIS trials were successfully completed in January 1923.

In spite of the accidents suffered by A-6031 and A-6032, and before completion of the BIS trials with A-6033, the USN had already decided to order the DT-2 into quantity production as, during competitive trials, it had been found superior to its four competitors on almost all counts, its ease of maintenance and handling and its strong structure being particularly praised. Accordingly, Contract Nos. 55991 and RNAF-62, respectively covering eighteen DT-2s (A-6405 to A-6422) and six DT-2s (A-6423 to A-6428), were awarded to the Douglas Company and to the Naval Aircraft Factory (NAF) Philadelphia, while eleven additional DT-2s (A-6085 to A-6095) were ordered from the Dayton-Wright Company at Dayton.

In anticipation of its first production contract, the Douglas Company, which in July 1921 had succeeded the Davis-Douglas Company, had to find larger quarters to house its expanded activities, and the DT-2s became the first aircraft to be built in the Wilshire Boulevard plant in Santa Monica.

During the course of Douglas' initial production contract the shape of the aircraft's vertical tail surfaces was changed when a balanced rudder of increased height and area was fitted. The first production DT-2 (A-6405) was accepted by the USN on October 19, 1922, and delivered to Torpedo Squadron Two (VT-2) which had taken delivery of its first four aircraft (A-6406 to A-6409) on December 12, 1922. By that time, however, the DT-2 had won an enviable reputation and a repeat order for twenty aircraft (A-6563 to A-6582) had been awarded to Douglas, while twenty additional DT-2s (A-6583 to A-6602) were ordered from the Lowe-Willard-Fowler (LWF) Engineering Co. of College Point, New York. The last Douglas-built DT-2s from the second production batch were accepted in October of that year.

The soundness of the DT design won for Douglas its first export orders and resulted also in the first construction under license by a foreign manufacturer of a Douglas-designed aircraft. This notable event was achieved in 1924 when the Norwegian Government placed an order for one DT-2B and acquired a manufacturing license. Powered by a 450 hp Liberty engine, the Douglas-built DT-2B was fitted with the nose radiator and tail surfaces developed for the Douglas World Cruiser and was followed by seven other machines built under license by the Marinens Flyvebätfabrik (Naval Flying Boat Factory) in Norway. Another export order was received by Douglas from the Peruvian Navy, and four DTBs (c/n 253, 254, 384 and 385) – similar to the DT-2B but powered by a 650 hp Wright Typhoon liquid-cooled engine – were built in 1927 and 1929 to bring to a close the production of DT-type aircraft."