The Waco Aircraft Company (WACO) was an aircraft manufacturer located in Troy, Ohio, United States. Between 1920 and 1947, the company produced a wide range of civilian biplanes.
The company initially started under the name Weaver Aircraft Company of Ohio but changed its name to the Waco Aircraft Company in 1928/29.
WACO (referring to the aircraft) is usually pronounced "wah-co" (the first syllable pronounced as in "water"), not "way-co" like Waco, Texas, whose name is entirely unrelated. Several companies operated under the Waco name, with the first company being the Weaver Aircraft Company, a firm founded by George E. Weaver, Clayton Bruckner, and Elwood Junkin in 1920 in Lorain and Medina, Ohio after they had already been collaborating for several years. In the spring of 1923 this became the Advance Aircraft Company in Troy, Ohio, after the departure of Weaver. At some point (when is not at all clear from the records but 1928 or 1929) it was changed from Advance Aircraft Company to Waco Aircraft Company. The firm is often confused with Western Aviation Company, the name of four unrelated aircraft enterprises in Chicago, Illinois; San Antonio, Texas; and Burbank, California.
Waco's history started in 1919 when businessmen Clayton J. "Clayt" Brukner and Elwood "Sam" Junkin met barnstorming pilots Charles "Charley" William Meyers and George "Buck" Weaver. Although their initial floatplane design was a failure, they went on to found the Waco company in 1920 and established themselves as producers of reliable, rugged planes that were popular with travelling businessmen, postal services and explorers, especially after the company began producing closed-cabin biplane models after 1930 in addition to the open cockpit biplanes. The Waco name was extremely well represented in the U.S. civil aircraft registry between the wars, with more Wacos registered than the aircraft of any other company. Production types including open cockpit biplanes, cabin biplanes and cabin sesquiplanes (known by Waco as Custom Cabins) as well as numerous experimental types
Waco had been building a series of successful cabin biplanes, when in 1935 they introduced a new series of upmarket cabin sesquiplanes intended for the wealthy private individual or business. The original biplanes had been given a designation ending in C, however with the new Custom Cabin, Waco decided to differentiate the new design and existing C types that remained in production were recoded as C-S types to indicate Standard Cabin, until Waco changed their designation again in 1936 to just an S. For example, the 1934 Standard Cabin YKC was redesignated as a YKC-S in 1935, and as a YKS-6 in 1936. 1936 also saw the adoption of a numerical suffix to indicate the model year of the design, as "-6" for 1936, "-7" for 1937, etc. Since it referred to a model and not the year of production, the "-7" was carried into 1939 for some Custom Cabins, while others were designated "-8". In 1936, Waco started using a short form to refer to the types of aircraft without the engine and model identifiers resulting in C-6, C-7 and C-8 however as Waco only built one type of Custom cabin in each of those years, they refer to the QC-6, GC-7 and GC-8 series respectively.
Waco civilian designations describe the configuration of the aircraft. The first letter lists the engine used, the second the specific type, and the third the general series. The coding system was changed in 1929 with several letters reassigned, and later with the introduction of the Custom Cabin series, the third letter 'C' was initially replaced with C-S (Cabin-Standard) and finally S. The numeral suffix represents the first year of production if it is 6 or higher (6=1936), or a sub type if 2 or less. Thus EGC-7 is a Wright R-760-E2 (350 hp (261 kW)) engined, cabin biplane airframe, custom cabin model first manufactured in 1937. Many Waco Cabin Biplanes that were originally sold as civilian aircraft, were impressed into military service in World War II. The United States Army Air Forces classified theirs regardless of type as Waco C-72s, with type letters identifying specific models. Other countries used other designations for their own Wacos.