Design Origins and Development
The SA-104 Cavalier emerged from Stan McLeod's adaptation of Yves Gardan's French GY-20 Minicab, originally designed in 1949. McLeod translated and modified the original plans to create a homebuilt aircraft specifically tailored for North American builders and powerplants. The design philosophy centered on providing amateur constructors with a straightforward wooden aircraft that could accommodate various engine configurations while maintaining structural integrity and performance.
The Cavalier series demonstrated remarkable versatility through its interchangeable landing gear configurations, allowing builders to choose between fixed or retractable systems in either tricycle or conventional arrangements. The SA-104 specifically represented the tricycle gear Super Cavalier variant, engineered to handle the increased power and weight of larger engines compared to earlier models in the series.
Construction and Technical Innovation
The SA-104's all-wooden construction employed traditional building techniques accessible to amateur constructors. The wing design featured single box spars with plywood leading edges and fabric covering, utilizing NACA 23115 airfoil at the root tapering to NACA 23010 at the tips. This wing configuration provided 117 square feet of wing area across the 27-foot 4-inch span, delivering predictable handling characteristics suitable for recreational pilots.
The aircraft's modular design philosophy extended beyond landing gear options to include optional wingtip fuel tanks, increasing total fuel capacity from 34 US gallons in the main tanks to 56 US gallons with the additional 22-gallon tip tanks installed. This fuel capacity enhancement significantly extended the aircraft's range capabilities for cross-country flying.
Powerplant Flexibility
Early Cavalier models accommodated four-cylinder engines weighing up to 235 pounds and producing 85 to 135 horsepower, including Continental O-200, Lycoming O-235, and Franklin 4AC powerplants. The Super Cavalier variants, including the SA-104, expanded this envelope to accept engines producing up to 200 horsepower, providing builders with greater flexibility in powerplant selection based on performance requirements and budget considerations.
This engine compatibility range allowed the SA-104 to serve various mission profiles, from basic recreational flying with smaller engines to more demanding cross-country touring with higher-powered installations. The tricycle gear configuration particularly suited the aircraft for operations from paved airports where ground handling ease was prioritized.
Manufacturing and Distribution
K & S Aircraft of Calgary, Alberta, Canada, marketed the SA-104 as construction plans rather than factory-built aircraft, following the established homebuilt aircraft model. This approach made the design accessible to individual builders while avoiding the regulatory complexities and capital requirements of certified aircraft production. Plans distribution later transferred to MacFam, ensuring continued availability to the homebuilding community.
The company's focus on plans sales rather than complete aircraft manufacturing reflected the homebuilt aviation market's structure, where builders typically preferred the cost savings and personal satisfaction of constructing their own aircraft. No specific production totals exist for the SA-104, as individual builders constructed aircraft from purchased plans without centralized reporting.
Operational Characteristics
The SA-104's side-by-side seating configuration accommodated one pilot and one passenger, with earlier series models offering an optional third jump seat. The gross weight of 1,850 pounds provided reasonable useful load for two occupants and baggage, making the aircraft suitable for weekend recreational flying and limited cross-country touring.
Operational flexibility remained a key characteristic, with the tricycle gear configuration offering easier ground handling compared to conventional gear variants. This feature particularly appealed to pilots transitioning from modern training aircraft or those operating from airports where ground handling assistance might be limited.
Current Status and Legacy
The SA-104's legacy continues through surviving examples in private hands, though exact numbers remain unknown due to the homebuilt nature of the design. At least one Cavalier variant is displayed at Winnipeg James Armstrong Richardson International Airport's main terminal in Canada, preserving the design's heritage for public viewing.
Photographic evidence confirms ongoing operations of Cavalier series aircraft internationally, including documented examples in New Zealand, indicating the design's global appeal among homebuilders. The aircraft's ICAO type designation SA04 confirms its recognition within international aviation databases, facilitating flight operations and regulatory compliance for remaining airworthy examples.