Northrop 4A Alpha
Introduced in 1930, the Northrop Alpha represents a transitional air transport design, a blend of old and new aircraft technology. The Alpha could enclose six passengers in a snug, comfortable cabin, but the pilot remained exposed to the elements. The aircraft was all metal and streamlined, but had fixed landing gear and only one engine.
Designed by John K. "Jack" Northrop, the Alpha was a great step forward in metal aircraft. Many of its features, particularly the multicellular wing design, were later used in the Douglas DC-2 and DC-3. Although more powerful twin-engine aircraft rendered the Alpha obsolete for passenger service, it continued to serve as a fast express cargo plane.
This aircraft was restored by volunteers from Trans World Airlines.
Gift of Trans World Airlines, Inc.
Air transport; mail plane; single engine; mono plane.
- Country of Origin
- United States of America
- Northrop Aircraft Inc.
- Overall: Aluminum
- Wingspan: 13.4 m (41 ft 10 in)
- Length: 8.7 m (28 ft 5 in)
- Height: 2.7 m (9 ft)
- Weight, gross: 2,043 kg (4,500 lb)
- Weight, empty: 1,208 kg (2,660 lb)
- Top speed: 272 km/h (170 mph)
The Northrop Alpha represents a notable point of transition in modern airline design, for it combined features of the past and of the future in a very utilitarian package. The passengers were enclosed in a comfortable cabin, while the pilot remained exposed—and sensitive—to the elements. The modern aspects of the Alpha—an all-metal structure, semimonocoque fuselage, and cantilever wing—were partially offset by the use of a single engine and fixed gear.
John K. Northrop, who had previously designed the Lockheed Vega, conceived of the Alpha as a means of proving his ideas for quantity production of an all-metal airplane with the machine tools existing in the early 1930s. Always pioneering new ideas and new techniques, Northrop became one of the most influential men in the aviation industry.
The Alpha was designed to be a high-performance plane that could carry mail and passengers out of small fields. The plane was attractive to airlines because of its comparatively high top speed (177 mph for later models) and high reliability. The latter was due in large part to the use of the dependable air-cooled Pratt and Whitney Wasp engine of 420 horsepower.
With the advent of the larger twin-engine Boeing and Douglas transports, the Northrop Alphas were relegated to carrying freight, serving well in this capacity. The Alpha could fly from coast to coast in twenty-three hours, carrying such commodities as freshly cut gardenias, silk worms, medical serums, and auto parts. Stops were made at Winslow (Arizona), Albuquerque, Amarillo, Wichita, Kansas City, St. Louis, Terre Haute, Indianapolis, Columbus, Pittsburgh, Philadelphia, and New York.
Although the Alpha served well, its real importance was its demonstration of Northrop’s multicellular wing and stress skin construction. These concepts were of fundamental importance to the Douglas DC-2 and DC-3.
The museum’s Alpha, NC11Y, was the third to be built. It was rolled out in November 1930 and became the personal plane of Col. C. M. Young, assistant secretary of commerce for aeronautics. Later, it was owned by the Ford Motor Company and National Air Transport before being sold to Transcontinental and Western Air, Inc.
NC11Y was retired sometime after 1934 and was sold to Frederick B. Lee, who outfitted it with floats for a projected round-the-world flight. The project was not completed, and the veteran Alpha passed through the hands of a succession of owners until purchased by Foster Hannaford, Jr., of Winnetka, Illinois, in May 1946. Hannaford hoped to restore the Alpha to flying condition, but was unable to do so before he died in 1971. The airplane was willed to the Experimental Aircraft Association (EAA) in Hales Corners, Wisconsin.
The National Air and Space Museum learned of the Alpha’s existence and negotiated with the EAA and with Trans World Airlines for its restoration. TWA undertook the project, and a group of volunteers under the direction of Dan McGrogan brought the aircraft back to its present almost "as new’ condition.