Boeing Model 40

Boeing Model 40
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Type	Mail plane
Manufacturer	Boeing
Maiden flight	20 July 1925
Introduced	1 July 1927
Number built	ca. 80

The Boeing Model 40 was a United States mailplane that became the first aircraft built by Boeing to carry passengers. It was of conventional biplane configuration with a combination of standard and warren-truss style interplane struts. Originally designed to compete for a US Mail contract in 1925, it was rejected in favour of the Douglas M-2.

The design was revived in 1927 as part of Boeing's tender for newly-privatised airmail routes. Designated the Model 40A, this variant was powered by an air-cooled Pratt & Whitney Wasp radial engine, which offered a 200 lb weight saving over the water-cooled Liberty specified by the postal service in 1925. Although the primary purpose of the aircraft was to carry mail, two passengers could be accommodated in the small cabin, allowing Boeing to operate it on any of the routes that the firm might bid for. The original fuselage design was changed to one using welded steel tubing.

Boeing successfully bid on the San Francisco-Chicago route, and Boeing Air Transport commenced operations on 1 July 1927 with 24 Model 40As.

Survivors

As of February 17, 2008, Boeing 40C S/N 1043 became the only airworthy example in the world. It also holds the title of the oldest flying Boeing in the world. In 1928, the aircraft was substantially damaged in a crash and we totally rebuilt by Pemberton and Sons Aviation in Spokane, Washington..

The Henry Ford Museum in Dearborn, Michigan, contains a 1927 Boeing 40B-2, number 285.

Variants

• Model 40 - original 1925 design with Liberty Engine
• Model 40A - revised 1927 design for BATC (25 built)
• Model 40B - Model 40As re-engined with Pratt & Whitney Hornet (19 converted). Redesignated 40B-2
  • Model 40B-4 - revised Model 40B with seating for four passengers and other improvements (38 built)
    • Model 40B-4A - one Model 40B used as engine testbed by Pratt & Whitney
    • Model 40H-4 - four Model 40B-4s built by Boeing Canada
• Model 40C - Similar to Model 40B-4 but with Pratt & Whitney Wasp engine of Model 40A. (10 built, all later converted to Model 40B-4 standard)
• Model 40X - unique special-order machine similar to Model 40C with only two-passenger cabin and extra open cockpit forward of pilot's cockpit
• Model 40Y - unique special-order machine similar to Model 40X, but with Pratt & Whitney Hornet engine

References

• Taylor, Michael J. H. (1989). Jane's Encyclopedia of Aviation. London: Studio Editions, 170. 
• World Aircraft Information Files. London: Bright Star Publishing, File 890 Sheet 52. 

Boeing History - Boeing Model 40A Commercial Transport Retrieved June 17, 2006.

See also

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Boeing Model 40".