Boeing Model 40

Boeing Model 40
Boeing Model 40
Type:	Single-engine biplane
Design country:	United States
Manufacturer:	Boeing
First flight:	July 7, 1925
Commissioning:	July 1, 1927
Production time:	1927 to 1932
Number of pieces:	77

The Boeing Model 40 was a single-engine mail plane designed as a biplane from the 1920s. It was the first model from the American manufacturer Boeing to be used for passenger transport .

history

In 1925, the US Mail needed an airplane to carry mail. Boeing then developed the Model 40, which made its maiden flight on July 7, 1925. In the competition it was defeated by the Douglas M-2 . In 1927 the design for the Model 40A was further developed, with which Boeing took part in the bidding process for the privatized airmail routes. On May 20, 1927, the new version made its maiden flight.

The US Mail originally called for the outdated Liberty engine to be used as the drive for the conventionally designed double-decker, which was to come from military stocks. In the new version it was replaced by the lighter Pratt & Whitney Wasp engine, which increased the payload and reduced operating costs. The frame now consisted entirely of welded metal tubes, and wooden structures covered with fabric served as wings. To ensure that it can be used on as many advertised routes as possible, the developers set up two passenger seats in the cabin.

Boeing was awarded the contract for the airmail route between San Francisco and Chicago , which was operated from July 1, 1927 by the Boeing Air Transport Corporation with 24 Boeing 40A.

By the time production was discontinued in 1932, a total of 77 aircraft in different variants were built. The most successful version was the model 40B-4 designed for four passengers.

Versions

• Model 40 - 1925 prototype with Liberty engine
• Model 40A - improved version from 1927 with Wasp engine for Boeing Air Transport (25 aircraft)
• Model 40B - former Model 40A with Pratt & Whitney Hornet engine; later referred to as 40B-2 (19 conversions)
  • Model 40B-4 - improved Model 40B with four passenger seats and other changes (38 aircraft)
    • Model 40B-4A - a Model 40B for Pratt & Whitney , used as a test aircraft
    • Model 40H-4 - four Model 40B-4s built by Boeing Canada
• Model 40C - Model 40B-4 with Wasp engine (ten aircraft, later converted to 40B-4)
• Model 40X - individual custom-made 40C with only two passenger seats and an additional open cockpit in front of the cockpit
• Model 40Y - individual custom-made model 40X with Hornet engine

Technical specifications

Three-sided view

Parameter	Data (Model 40A)
crew	1
Passengers	2
length	10.12 m
span	13.47 m
height	3.73 m
Wing area	50.82 m²
Empty mass	1602 kg
Takeoff mass	2722 kg
Cruising speed	169 km / h
Top speed	206 km / h
Service ceiling	4420 m
Range	1050 km
Engines	a 9-cylinder radial engine Pratt & Whitney Wasp with 425 HP / 313 kW

Received aircraft

Boeing 40C

• the Boeing 40C S / N 1043 is the only remaining airborne aircraft, making it the world's oldest flying Boeing.
• the Henry Ford Museum in Dearborn , Michigan owns a Boeing 40B-2, number 285, built in 1927.
• the Museum of Science and Industry in Chicago , Illinois exhibits a Boeing Model 40-B from 1928 (N288).
• the Museum of Flight in Seattle , Washington has a full replica and two hulls under construction as an example of the production facilities in the late 1920s.

See also

• List of aircraft types

Web links

Commons : Boeing 40  - collection of images, videos and audio files

• Model 40 Commercial Transport. In: History. The Boeing Company, accessed April 27, 2017 (English, image and data). 

Individual evidence

1. ^ Peter M. Bowers: Boeing Aircraft since 1916 , p. 124