The Marathon was designed to comply with the US FAR 103 Ultralight Vehicles two-seat trainer rules and today is marketed as a light-sport aircraft. The aircraft takes its name from its design goal of an aircraft with long range and endurance and features a range of 1150NaN0. It features a parachute-style high-wing, two-seats-in-tandem accommodation, tricycle landing gear and originally a single 500NaN0 Rotax 503 engine in pusher configuration. The 640NaN0 Rotax 582 was the standard engine used on later models.[4]
The aircraft is built from a combination of bolted dural aluminium and stainless steel tubing. It features a double ring propeller guard that has been roll-over tested. The fuel tank is made from aluminium. In flight steering is accomplished via foot pedals, or optionally a control stick, that actuate the canopy brakes, creating roll and yaw. On the ground the aircraft has lever-controlled nosewheel steering. The main landing gear incorporates gas strut suspension. The aircraft is factory supplied in the form of an assembly kit that requires 30–50 hours to complete.[3]
Originally marketed by the factory under their own name, the aircraft was later marketed under the brand name Blue Heron, although the manufacturer remained the same.[3]