Waco 9


Display Status:

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Collection Item Summary:

The name "Waco" has long been synonymous with popular open-cockpit biplanes of the golden age of flight, the late 1920s and the 1930s. Clayton Brukner and Elwood Junkin, first of the Weaver Aircraft Company, known as Waco, and then the Advance Aircraft Company, designed the three-place Model 9 around the World War I-surplus Curtiss OX-5 engine in 1925. The rugged but graceful aircraft quickly found favor as a barnstorming, racing, and all-around utility aircraft.

The Museum's Waco 9, N452, serial number 389, had a succession of owners in the mid-west United States. In 1966, owner Marion McClure retired the antique aircraft when it did not meet the safety requirements of brakes and tail-wheel at his local airport. In 1972, original Waco partner and designer Clayton J. Brukner purchased the aircraft to donate it to the Museum.

Manufacturer: The Advance Aircraft Company, Troy, Ohio, 1927.

Collection Item Long Description:

The name 'Waco" has long been synonymous with popular biplanes of the "golden age" of flying, the late 1920s and the 1930s. In 1920, George "Buck" Weaver, Charlie Meyers, Clayton Brukner, and Elwood Junkin formed the Weaver Aircraft Company in Lorain, Ohio. It was Brukner and Junkin who established the Waco name as an enduring line of versatile and classic aircraft.

The Weaver Aircraft Company, known as "Waco," built a few aircraft and moved to Troy, Ohio, in 1923, as the Advance Aircraft Company. After the death of Weaver in 1924, Brukner and Junkin took over the business and introduced the Model 9, or Nine, in 1925. It was an immediate success for several reasons. First, war surplus Curtiss Jennies and the like were becoming less available but more importantly, the Nine was a well-designed aircraft, built around the available Curtiss OX-5 or Wright Hispano engines, with better performance than the Jenny and a reasonable price tag. The bench seat in the front cockpit could snugly accommodate two passengers; the single cockpit for the pilot was in the rear. The company entered the Nine in the Ford Air Tour of 1925 in which performed admirably and the publicity resulted in good sales. At least 14 Waco 9s participated in the National Air Races in 1926, and several Waco pilots won their events. Aside from its use as an excellent barnstorming and racing plane, it also served in the aerial spray business and in early airline use; Clifford Ball's airlines and Embry-Riddle Company both used Wacos in 1927. Edo floats could also be attached for water operations.

New regulations of the emerging aircraft industry in the mid-twenties soon challenged all contemporary designs. Barnstormers had often cut corners by using aircraft of questionable airworthiness and many pilot qualifications were also questionable. A series of accidents and a mounting public demand resulted in the government licensing of pilots and aircraft. The new Air Commerce Department Regulations of December 31, 1926, required that all aircraft manufacturers secure an Airplane Type Certificate, or ATC, for their products. To be issued an ATC, the manufacturer had to submit strength calculations for the design and then demonstrate through static tests on a prototype that it met or exceeded minimum standards. Aircraft production today must still meet these requirements.

Because neither of the designers of the Waco 9 had more than a high school education, they feared that the airplane was doomed. However, a professor at Massachusetts Institute of Technology made stress calculations, and the U.S. Army bought one and static-tested it to destruction at McCook Field. The Air Commerce regulations required the structure to be able to withstand a load 6.5 times its own weight. The Waco 9 held up to a factor of 7.5 and was subsequently issued ATC number 11 in July 1927.

Construction of the Nine was typical of the time: welded steel tubing with all-wood wing structure, entirely fabric-covered. The engine radiator was mounted under the leading edge of the center portion of the upper wing and became a Waco trademark. Large cable-operated ailerons were attached to the upper wings too. The landing gear was a straight-axle type. The standard finish was silver-painted fabric with blue paint on the exposed metal parts. The attributes of good performance and reliability combined with attractive design resulted in a production of about 276 Waco 9s from 1925 to 1927. By then, its new and improved sister ship, the Waco 10, outsold the Nine.

The museum's Waco 9, N452, serial number 389, with a 1918 Curtiss OX-5 engine, was manufactured in May 1927. Knapp Flying Service of Ypsilanti, Michigan, purchased it and it then went through a succession of owners in the Midwest: James Foster of Lansing (1927); Otto Haskins of Battle Creek (1932); Lorne Dobbie of the same city the next year; Charles Smith, Tecumseh (1935); Albert Exline, Dayton, Ohio (1941); Paul Pfoutz, Dayton (1944); Walter Alpiger, Louisville, Kentucky (1959); Robert Gehrig, Fort Wayne, Indiana (1961); and Marion McClure, Bloomington, Illinois (1960).

McClure flew the Nine until 1966, when flight-safety requirements at his airport restricted the use of aircraft without a tail wheel or brakes. Rather than modify the aircraft, he took it out of service. The original co-designer and company partner, Clayton J. Brukner, wishing to contribute a Waco to the Smithsonian Institution, purchased the airplane in 1972 for donation to the National Air and Space Museum. The paint scheme is a non-factory scheme. The aircraft is currently at the Museum's Paul E. Garber Restoration and Storage Facility in Suitland, Maryland.

Data Source

National Air and Space Museum

Restrictions & Rights

Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum


Credit Line

Gift of Clayton J.. Brukner


  • Fuselage: steel tube, fabric-covered
  • Wings: wood, fabric-covered


  • Wingspan: 9.54 m (31 ft. 4 in.)
  • Length: 7.19 m (23 ft. 6 in.)
  • Height: 2.82 m (9 ft. 3 in.)
  • Weight: Empty 600 kg (1,320 lbs.)
  • Weight: Gross 953 kg (2,100 lbs.)
  • Engine: Curtiss OX-5, 90 hp

Country of Origin

United States of America



Physical Description

Two-seat, general aviation biplane; red and black with OX-5 engine.



Inventory Number


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