Most toy helicopters use electric motors, but the concept of a full-size electric 'copter has long been scuttled by the heavy batteries it would require. In recent years, however, battery technology has progressed to the point where Sikorsky thinks this is now a workable idea, and they have retrofitted a 50-year-old design with electric power to prove it.
Based on Sikorsky's long running S-300C trainer, the Firefly dumps the original's 190-hp four-cylinder gas engine for an electric motor and a bunch of lithium-ion batteries. Battery duration is only around 15 minutes — not too good, but at least it allows them to show that concept has merit. Sikorsky's head of research and engineering Mark Wilner says rising fuel costs are starting to threaten the role helicopters play in many fields, making research into alternate fuels essential.
Sikorsky will unveil Project FIrefly Tuesday at the Experimental Aircraft Association (EAA) AirVenture show in Oshkosh Wisconsin.