Northrop Alpha
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The Northrop Alpha was an American single-engine monoplane fast mail/passenger transport aircraft used in the 1930s.
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[edit] Development
Drawing on his experience with the Lockheed Vega, John K. Northrop designed an advanced mail/passenger transport aircraft. In addition to all-metal construction, the new Alpha benefitted from two revolutionary aerodynamic advancements -- wing fillets researched at the Guggenheim Aeronautical Laboratory at the California Institute of Technology, and a multicellular stressed-skin wing of Northrop's own design which was later successfully used on Douglas DC-2 and Douglas DC-3. In addition, the Alpha was the first commercial aircraft to use rubber deicer boots on wing and empennage leading edges which, in conjunction with state-of-the-art radionavigation equipment, gave it day-or-night all-weather capability. The aircraft first flew in 1930, with a total of 17 built.
The Alpha was further developed into a dedicated fast transport Northrop Gamma.
[edit] Operational history
The Alpha entered service with Transcontinental & Western Air (future TWA) making its inaugural flight on 20 April 1931. The trip from San Francisco to New York required 13 stops and took just over 23 hours. TWA operated 14 aircraft until 1935, flying routes with stops in San Francisco, California; Winslow, Arizona; Albuquerque, New Mexico; Amarillo, Texas; Wichita, Kansas; Kansas City, Missouri; St. Louis, Missouri; Terre Haute, Indiana; Indianapolis, Indiana; Columbus, Ohio; Pittsburgh, Pennsylvania; Philadelphia, Pennsylvania; and New York. Three Alphas were operated by the US military as C-19 VIP transports until 1939.
The third Alpha built, NC11Y, is preserved at the Smithsonian National Air and Space Museum.
[edit] Variants
- Alpha 2 - six-passenger version
- Alpha 3 - two-passenger plus cargo version, several Alpha 2s were converted to this configuration
- Alpha 4 - cargo version with 2 ft (0.6 m) increased wingspan, all converted from Alpha 3s
- Alpha 4A - cargo version, all converted from Alpha 4s
- C-19 - military VIP transport, seating reduced to 4 passengers
[edit] Users
Trans World Airlines, US Army Air Corps
[edit] Specifications (Alpha 2)
General characteristics
- Crew: 1
- Capacity: 6 passengers
- Length: 28 ft 5 in (8.7 m)
- Wingspan: 41 ft 10 in (12.8 m)
- Height: 9 ft 0 in (2.7 m)
- Wing area: 295 ft² (27.4 m²)
- Empty weight: 2,590 lb (1,177 kg)
- Loaded weight: 4,500 lb (2,045 kg)
- Useful load: 1,910 lb (868 kg)
- Max takeoff weight: lb (kg)
- Powerplant: 1× Pratt & Whitney Wasp R-1340-SC1 , 420 hp (313 kW)
Performance
- Maximum speed: 177 mph (285 km/h)
- Cruise speed: 145 mph (233 km/h)
- Range: 1,650 mi (2,650 km)
- Service ceiling: 19,300 ft (5,885 m)
- Rate of climb: 1,400 ft/min (7.1 m/s)
- Wing loading: 15.3 lb/ft² (74.6 kg/m²)
- Power/mass: 0.09 hp/lb (0.15 kW/kg)
[edit] References
- Smith, MJ, Jr. (1986) Passenger airliners of the United States, 1926-1991. Pictorial Histories Publishing Company. ISBN 0-933126-72-7
[edit] Related content
Related development
- Lockheed Vega
- Northrop Beta
- Northrop Gamma
- Northrop Delta
- Douglas DC-2
- Douglas DC-3
Comparable aircraft
- Boeing Monomail
- Lockheed Model 9 Orion