Although the Model-6D (B-1D) shared a similar designation with the 1919 B-1 (Model-6) flying boat and is listed in Boeing documents as a four-seater variant of the latter, it was structurally a completely new aircraft. Apart from the general layout, the only similarity was the shape of the rudder.
Innovative Design
The boat’s hull in the upper part had a box-like cross-section (the B-1 had a semicircular one), the contours of the nose were modified, and spray deflectors appeared above the chines. The pilot and three passengers were accommodated under a shared angular canopy.
The wing structure was entirely new: it used shortened wing panels from the Model-40, with the joint of the upper wing panels similarly located to the left of the axis of symmetry. Each side had one pair of interplane struts (the B-1 and Model-40 had two pairs). The stabilizer, like on the B-1, was supported by L-shaped struts but had a different shape and greater span.
The engine, like on the B-1, drove a pusher propeller, but it was now a 220 hp five-cylinder radial Wright J-5 “Whirlwind.”
Development and Variants
The development of the aircraft began in 1928. In May, the first of two examples (factory No. 1029) was built. The first flight took place in April; after testing, the aircraft was sold to Canada and registered as G-CASX.
The second aircraft, with an earlier factory No. 1028 but completed later, was equipped with a 420 hp P&W “Wasp” engine and registered as NC-5270.
Technical Specifications
| Modification | Model 6D |
| Wingspan, m | 12.10 |
| Length, m | 9.37 |
| Height, m | 3.66 |
| Wing area, m2 | 43.29 |
| Empty weight | 1017 |
| Maximum takeoff weight | 1516 |
| Engine type | 1 Piston engine Wright J-5 |
| Power, hp | 1 x 220 |
| Maximum speed, km/h | 153 |
| Cruising speed, km/h | 129 |
| Practical range, km | 282 |
| Service ceiling, m | 3656 |
| Crew, crew members | 1 |
| Payload | 3 passengers |
Image and diagram gallery of the Boeing Model 6D (B-1D)
 Boeing Model 6D (B-1D) |
 Boeing Model 6D (B-1D) |
 Boeing Model 6D (B-1D) |
 Boeing Model 6D (B-1D) |
 Boeing Model 6D (B-1D) |
 Boeing Model 6D (B-1D) |