High Quality Content by WIKIPEDIA articles! The Waco A series is a range of light American-built twin side-by-side seater sporting biplanes of the early 1930s.The Waco A series was introduced in 1932 as an affordable private-owner aircraft with cross-country range and baggage capacity and a more sporting image than the larger Waco F series. The A series offered a number of engine options which had varying sub-designations. The power range lay between the KBA with a 100 hp (75 kW) Kinner engine and the later UBA with a 210 hp (157 kW) Continental powerplant.