Design and Development
The Chinook emerged from the drawing board of Ukrainian-born aeronautical engineer Vladimir Talanczuk, a graduate of the Polish Institute for Aviation Specialists who designated this design as his eleventh aircraft project. Working with Dr. Dave Marsden at the University of Alberta, Talanczuk developed a specialized airfoil designated UA 80/1 specifically for the aircraft's performance requirements.
Talanczuk's design objectives prioritized practical amateur construction, with the WT-11 engineered for 100-hour assembly time by first-time builders. The innovative wing attachment system allowed two people to remove the wings in just 15 minutes, addressing storage and transportation concerns for ultralight operators. The aircraft featured sealed-gap tail surfaces and initially incorporated "gapless" ailerons, though conventional ailerons replaced this system in 1986 due to operational challenges.
Early Success and Recognition
Following its maiden flight on December 12, 1982, the Chinook quickly established itself as a standout design in the emerging ultralight market. Test pilot Dennis Maland demonstrated the aircraft's capabilities in August 1983, climbing a Rotax 277-powered WT-11 to 18,500 feet, showcasing exceptional altitude performance for an ultralight aircraft.
The design's excellence earned immediate industry recognition when the Chinook WT-11 captured Reserve Grand Champion honors at AirVenture in both 1983 and 1984, establishing its reputation among aviation enthusiasts and potential builders.
Production History
Birdman Enterprises of Edmonton, Alberta launched commercial production in 1983, manufacturing kits at the Canadian Ultralight Manufacturing facility in St. Paul, Alberta. The company offered the WT-11 kit for Can$7,995 (US$6,395) in 1984, making it accessible to recreational pilots seeking an affordable entry into aviation.
Production proved remarkably successful, with Birdman Enterprises delivering close to 700 aircraft before ceasing operations in late 1987. The company's brief but intensive four-year production run established the Chinook as one of the most popular ultralight designs of the decade.
Continued Development
Following Birdman's closure, ASAP acquired production rights and resumed manufacturing from 1989 to 2013, focusing primarily on the two-seat Chinook Plus 2 variant. This extended production run added significantly to the type's numbers, with total completions eventually exceeding 850 aircraft.
The Couch family purchased the rights in 2013, requiring nearly three years to deliver their first aircraft under the new ownership. Aeroplane Manufactory subsequently handled parts production from 2016 through 2023, supporting the existing fleet of flying examples.
Technical Specifications and Variants
The original WT-11 employed the Rotax 277 two-stroke engine, manufactured by BRP-Rotax GmbH & Co KG of Austria. This powerplant proved adequate for the single-seat configuration, providing the climb performance demonstrated in Maland's altitude record flight.
The larger Chinook Plus 2 accommodated more powerful engines including the 50-horsepower Rotax 503, the 60-horsepower HKS 700E, the 64-horsepower Rotax 582, and the 80-horsepower Rotax 912. These engine options allowed operators to match powerplant selection to their specific performance requirements and budget constraints.
Operational Characteristics
Pilots praised the Chinook for its sprightly handling characteristics, though the design exhibited directional divergence in untrimmed flight conditions. The pusher configuration provided excellent forward visibility while the high-wing layout contributed to stable flight characteristics preferred by recreational pilots.
The seamless tail surface transitions enhanced control effectiveness, while the removable wing system proved popular among owners requiring hangar space or ground transportation capabilities.
Legacy and Current Status
The Chinook's production span of over three decades, across multiple manufacturers, demonstrates the enduring appeal of Talanczuk's design. With more than 850 completed examples, it ranks among the most successful ultralight aircraft designs, influencing subsequent pusher high-wing configurations.
While full kit production ended in 2023 with Aeroplane Manufactory's cessation of parts support, many examples remain airworthy in private hands. The type's significance extends beyond mere production numbers, representing the successful commercialization of amateur-built aviation during the ultralight boom of the 1980s and the sustainable adaptation of recreational aircraft designs across changing market conditions.