Genesis of a Naval Torpedo-Bomber
In the 1920s, the U.S. Navy Bureau of Aeronautics proposed a conceptual design for a new naval aircraft, soliciting construction proposals from several aviation companies. The new project incorporated insights from previous Curtiss and Martin torpedo-bomber designs, resulting in a large biplane. Boeing secured the contract to build this aircraft, designated as the Boeing Model 63.
The primary construction material for the aircraft was duralumin alloy. It featured non-retractable landing gear with two-wheeled main struts, and the design allowed for the replacement of the wheeled undercarriage with floats, providing versatility for different operational needs.
Limited Service and Operational Shifts
The first XTB-1 prototype took to the air in May 1927, and all three ordered aircraft were delivered to the U.S. Navy in June of the same year. However, these aircraft saw limited service. Even before their delivery, priority shifted to twin-engine aircraft, which were considered safer for flights over the sea, preventing the TB series from entering large-scale production.
Adaptation and Legacy
Despite its limited production, the TB airframe proved adaptable. It was later modified to accommodate a power plant consisting of two wing-mounted Wright R-1750 Cyclone radial engines. This new propulsion system was developed and tested on the XTN-1 prototype. Following these trials, a contract was awarded to Douglas for the construction of T2D aircraft, marking a transition in naval aviation development.
Technical Specifications
| Modification | XTB-1 |
| Wingspan, m | 16.76 |
| Length, m | 12. 45 |
| Height, m | 4. 12 |
| Wing area, m2 | 80. 64 |
| Empty weight | 2 558 |
| Normal takeoff weight | 4 339 |
| Engine type | 1 Piston engine Packard ЗА-2500 |
| Power, hp | 1 x 730 |
| Maximum speed, km/h | 185 |
| Cruising speed, km/h | 161 |
| Practical range, km | 1413 |
| Maximum rate of climb, m/min | 230 |
| Practical ceiling, m | 3810 |
| Crew, crew | 3 |
| Armament | one 7.62-mm Browning machine gun in the forward fuselage and one 7.62-mm Browning machine gun on a turret in the gunner’s cockpit; one 789-kg Bliss-Leavitt torpedo under the fuselage |
Image and diagram gallery of the TB-1
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