Luka Znidarsic and Matija Znidarsic, both experienced sailplane pilots and mechanical engineers in Slovenia, have developed a Front Electric Sustainer, a power system that provides a climb of 1.5 meters per second (198 feet per minute) for their prototype configuration on an 18-meter LAK 17. They designed their own motor and controller for the application. The motor is 5 kg (11 pounds), and puts out 15 kW (20.1 horsepower) at 85 Volts. Total weight for the power package is 35 kg (77 pounds), with batteries in two packs behind the rear spar, balancing the weight of the motor and propeller in the nose.
“Front” refers to the motor’s location, right in the nose of the sailplane. A 0.9 meter (35.4 inches) propeller automatically extends when the outrunner is operating, and folds against the nose of the fuselage when the motor is shut down. The standard nose cone or motor unit can be mounted when the sailplane is put in its trailer, without any modification to the trailer or mounting hardware.
First flight was October 30, 2009. We look forward to further developments.