Northrop Alpha 4A
Northrop · United States · first flew 1930 · transport aircraft
The Northrop Alpha was a pioneering all-metal low-wing monoplane that introduced stressed-skin construction and a multicellular wing structure to American commercial aviation in the early 1930s. It carried a pilot in an open cockpit and passengers or mail in an enclosed fuselage cabin.
Recognition (WEFT)
| W — Wings | Low-mounted, tapered |
|---|---|
| E — Engines | 1 × piston, nose-mounted |
| F — Fuselage | Open cockpit for pilot, enclosed passenger/mail compartment in fuselage |
| T — Tail | Conventional |
WEFT is AircraftIQ's four-point recognition method — how it works.
Spot it by:
- Low-wing all-metal monoplane with spatted fixed undercarriage
- Smooth stressed-skin construction
- Open cockpit for pilot, enclosed passenger/mail compartment in fuselage
The smooth metal skin, low tapered wing, spatted fixed undercarriage, and the distinctive arrangement of an open pilot cockpit aft of an enclosed passenger/mail fuselage section are identifying features.
Specifications
- The Northrop Alpha 4A has a length of 8.66 m (28 ft).
- It has a wingspan of 13.36 m (44 ft).
- Typical crew: 1.
Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.
History
Designed by Jack Northrop and first flown in 1930, the Alpha set new standards for speed and structural integrity for single-engined transports. Transcontinental Air Transport and then TWA used Alphas on mail routes, and the type demonstrated the superiority of all-metal stressed-skin construction over earlier fabric-covered and wooden designs.
Variants
The Alpha 1 through 4 represented progressive refinements; the 4A introduced detail improvements to the engine installation and undercarriage fairings; the Alpha influenced subsequent Northrop designs including the Beta and Gamma.
Where you'll see it
Alphas served primarily with TWA on domestic US airmail and passenger routes through the early 1930s, before being retired as faster and larger twin-engined types became available.
Related aircraft
- Northrop Gamma 2D
- Northrop A-17
- Northrop N-3PB
- Northrop Vengeance I
- Avro 624 Six
- Boeing Monomail
- Burnelli UB-20
- Douglas Dolphin
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