Design and Development
The AMAX Double Eagle TT emerged from Amax Engineering's efforts to create an accessible homebuilt autogyro for amateur constructors. The company, based in Donvale, Victoria, Australia, designed the aircraft to comply with amateur-built aircraft regulations while providing reliable recreational flight capabilities. The Double Eagle TT followed the company's earlier Eagle TT model, representing an evolution in their autogyro design philosophy.
The aircraft's construction centered on a welded 4130 steel tubing fuselage combined with aluminum components, providing both strength and reasonable weight. This mixed-material approach allowed builders to achieve the 575-pound empty weight while maintaining structural integrity. The tandem open cockpit configuration placed both occupants in the airstream, typical of recreational autogyros of the era.
Powerplant and Performance
Amax Engineering selected the Subaru EA82 automotive engine as the Double Eagle TT's powerplant, a four-cylinder, liquid-cooled unit producing 150 horsepower. This automotive conversion approach reflected the broader trend in experimental aviation toward utilizing reliable, cost-effective car engines rather than purpose-built aircraft powerplants. The engine drove a three-bladed ground-adjustable composite propeller in pusher configuration.
The Double Eagle TT's performance specifications demonstrated typical autogyro characteristics, with excellent short-field capabilities and modest cruise speeds. The aircraft achieved takeoff runs of just 200 feet and landing distances of 10 feet, made possible by the autogyro's unique aerodynamics. Maximum speed reached 100 miles per hour, while normal cruise operations proceeded at 70 miles per hour. With 12 gallons of fuel capacity, the aircraft provided a 300-mile range, suitable for local recreational flying.
The 31-foot diameter two-bladed main rotor generated sufficient lift to carry the 1,150-pound gross weight to a service ceiling of 14,000 feet. Rate of climb performance reached 1,000 feet per minute, respectable for an autogyro of this size and power loading.
The Manufacturer
Amax Engineering operated during the 1990s as part of Australia's growing experimental aircraft industry. The company focused specifically on autogyro designs, producing both the Eagle TT and Double Eagle TT models during this period. Located in Donvale, Victoria, the company served the niche market of homebuilders seeking rotorcraft alternatives to conventional fixed-wing aircraft.
The company appears to have ceased operations following the completion of Double Eagle TT production in the late 1990s, with no records indicating acquisition by other manufacturers or continuation under different ownership. Amax Engineering's brief operational period reflected the challenges facing small-scale aircraft manufacturers in the experimental market.
Kit Aircraft Operations
The Double Eagle TT was supplied exclusively as a kit for amateur construction, requiring an estimated 100 hours of assembly time. This relatively modest build time compared favorably with more complex homebuilt aircraft, making autogyro construction accessible to recreational builders. The kit approach allowed Amax Engineering to reach international markets while avoiding the regulatory complexities of certified aircraft production.
Homebuilders appreciated the Double Eagle TT's straightforward construction methods and conventional materials. The welded steel fuselage required basic metalworking skills, while the aluminum components used standard aviation construction techniques. The automotive engine installation provided familiar technology for builders with automotive experience.
Legacy and Current Status
The AMAX Double Eagle TT represents a specific period in Australian experimental aviation when small manufacturers explored autogyro designs for the homebuilt market. While production numbers remain unrecorded, the aircraft contributed to the broader acceptance of automotive powerplants in experimental aviation.
No surviving airworthy examples have been documented in available sources, and no major aviation museums currently display the type. The Double Eagle TT's legacy remains primarily within the specialized community of autogyro enthusiasts and Australian experimental aviation history.
The aircraft's significance lies in its demonstration of how small manufacturers could develop viable recreational aircraft designs during the 1990s experimental aviation boom. The successful integration of automotive powerplants with traditional aircraft construction methods influenced subsequent homebuilt designs across multiple manufacturers.