Conceptual design focusing on the ability of a
redundant electric propulsion system to provide new capabilities for Vertical
Takeoff and Landing aircraft. Specifically
utilizing electric motor variable rpm to accomplish a low tipspeed prop-rotor
(400 ft/sec tip speed at hover and 200 ft/sec at cruise) to accomplish an order
of magnitude reduction in community noise for close proximity operations (30-40
db reduction). The variable rpm capability also achieves a 25% improvement in
prop-rotor efficiency through operation at optimal advance ratios.