Boeing Model 40
Boeing · United States · first flew 1925 · transport aircraft
The Boeing Model 40 was an American single-engine biplane designed primarily to carry US airmail under Post Office contracts, with a small enclosed cabin for one or two paying passengers. It helped establish Boeing Air Transport, the precursor to United Air Lines.
Recognition (WEFT)
| W — Wings | High-mounted, straight |
|---|---|
| E — Engines | 1 × piston, nose-mounted |
| F — Fuselage | 10.16 m fuselage |
| T — Tail | Conventional |
WEFT is AircraftIQ's four-point recognition method — how it works.
Spot it by:
- 1920s US airmail biplane with passenger capacity
- Single radial engine with open cockpit for pilot
- Enclosed cabin for two or four passengers below wing
Classic open-cockpit biplane with a radial engine and an enclosed passenger cabin built into the lower fuselage; the combination of open pilot cockpit and enclosed passenger section is the key recognition feature.
Specifications
- The Boeing Model 40 has a length of 10.16 m (33 ft).
- It has a wingspan of 13.46 m (44 ft).
- Its maximum speed is 201 km/h (125 mph).
- Typical crew: 1 + 2-4 passengers.
Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.
History
Originally designed with a Liberty engine in 1925, the Model 40A was re-engined with the lighter Pratt & Whitney Wasp radial in 1927, enabling it to carry mail plus two passengers profitably. Boeing used the aircraft to win lucrative Post Office airmail contracts, and the Model 40B-4 expanded capacity to four passengers. The aircraft directly led to the formation of Boeing Air Transport and ultimately United Airlines.
Variants
The Model 40A used the Pratt & Whitney Wasp; the Model 40B-4 was stretched to carry four passengers; the Model 40C and H were further variants.
Where you'll see it
Operated by Boeing Air Transport on US airmail routes from 1927 to the early 1930s; helped establish the commercial aviation infrastructure of the United States.
Related aircraft
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