The Boeing TB (or Model 63) was an American torpedo bomber biplane designed by the US Navy and built by Boeing in 1927.

Development and design

The TB was an improved version of the Martin T3M. It was constructed of all dural, with a fabric covering. The equal-span wings were large and unstaggered, and could be folded aft, reducing the span to 21 feet 8 inches (6.60 m) for storage. The wheeled undercarriage was a conventional configuration that could be interchanged with floats. As a landplane, the main gear units carried twin wheels. The underside of the fuselage incorporated a glazed station for the bombardier.^[1]

Even before the three XTB-1s were delivered, the Navy's Bureau of Aeronautics had changed its opinion about what was needed in a torpedo bomber, and based on experience with the NAF XTN-1 had decided that a twin-engine aircraft would better suit the role. Having thus been made redundant, no TBs past the three prototypes were built.^[1]

Specifications

Data from Bowers 1966, p. 63

General characteristics

• Crew: Three - pilot, gunner, and bombardier
• Length: 40 ft 10 in (12.45 m)
• Wingspan: 55 ft 0 in (16.76 m)
• Height: 13 ft 6 in (4.12 m)
• Wing area: 868 sq ft (80.6 m²)
• Empty weight: 5,640 lb (2,558 kg)
• Gross weight: 9,786 lb (4,339 kg)
• Powerplant: 1 × Packard 3A-2500 , 730 hp (544 kW)

Performance

• Maximum speed: 115 mph (185 km/h, 100 kn)
• Range: 878 mi (1,413 km, 763 nmi)
• Service ceiling: 12,500 ft (3,810 m)
• Rate of climb: 754 ft/min (3.8 m/s)

Armament

• 1 × fixed, forward-firing .30 in (7.62 mm) M1919 Browning machine gun
• 1 × trainable, rearward-firing .30 in (7.62 mm) Browning machine gun
• 1 × Bliss-Leavitt torpedo