Sikorsky Firefly

Firefly
Sikorsky Firefly
Role	Light Experimental electric helicopter
Manufacturer	Sikorsky Aircraft
Developed from	Sikorsky S-300

The Sikorsky Firefly is an all-electric helicopter built for research purposes by Sikorsky Aircraft. It has been called the world's "first all-electric helicopter". The Firefly is a modified Sikorsky S-300C helicopter with its engine replaced by an electric motor and two lithium-ion battery packs. The helicopter can hold only the pilot, no passengers, and operate for 12 to 15 minutes. It has a top speed of 80 knots, or about 92 mph.

Sikorsky announced the existence of the new aircraft July 19, 2010 at the Farnborough International Air Show in the United Kingdom and displayed it for the first time at the Experimental Aircraft Association's AirVenture 2010 convention in Oshkosh, Wisconsin on July 26. It was expected that the helicopter would make its first flight in late 2010 or in early 2011.

The Firefly was created by replacing the engine of the S-300C light helicopter, which has been in use for nearly half a century, during which time more than 3,000 have been built. The S-300C's Lycoming 190-horsepower, 5.9-liter, 4-cylinder gasoline engine was replaced with an electric motor, new motor mount and two battery packs located on each side of the pilot. The rotor control, transmission and other systems were left essentially unchanged.

If the aircraft completely loses power, it can auto-rotate for a safe landing. The pilot should have plenty of warning if the batteries run down during flight.

The high-efficiency electric motor is powered by two battery packs (manufactured by Gaia) which have a total of 300 cells and produce about 370 volts. The electric motor is expected to fly with much less noise, emissions and vibration and require shorter maintenance periods over the life of the aircraft.

Eagle Aviation Technologies, LLC, installed the new electric motor and digital controller from U.S. Hybrid, and the batteries.

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Wikipedia