The "TT" designation indicates "Tall Tail". The aircraft has higher landing gear, allowing the engine to be placed on the vertical center of gravity, which eliminates pitch changes with throttle application.
The Double Eagle TT was designed to comply with amateur-built aircraft rules. It features a single main rotor, a two-seats-in tandem open cockpit without a windshield, tricycle landing gear with wheel pants and a four-cylinder, liquid-cooled, four-stroke, single-ignition 1500NaN0 Subaru EA82 automotive engine in pusher configuration.
The aircraft fuselage is made from welded 4130 steel tubing, with some aluminum parts. Its two-bladed rotor has a diameter of 301NaN1. The aircraft has a typical empty weight of 575lb and a gross weight of 1150lb, giving a useful load of 575lb. With full fuel of the payload for the pilot, passengers and baggage is 503lb.
The standard day, sea level, no wind, take off with a 1500NaN0 engine is 2000NaN0 and the landing roll is 100NaN0.
The manufacturer estimates the construction time from the supplied kit as 100 hours.