victor papa,
Pascal Chretien, who flew the first electric helicopter a couple of months ago, is also moving his interest toward hybrid propulsion for helicopters.
Sikorsky's patent application for ELECTRIC POWERED ROTARY-WING AIRCRAFT, which is covered on the PPRuNe thread
Is Sikorsky Attempting to Inhibit Others from Developing Electric Rotorcraft?, is before the Board of Appeals.
Hopefully, the US Patent Office will continue to decline Sikorsky's intent to patent that which already exists.
Dave