 A large duct at the fuselage's rear contains two counter-rotating propellers, which would be driven by two large electric motors.Power would be supplied by a lithium-air battery pack mounted in a detachable pod on the lower fuselage nose, where it could be removed and replaced as part of the normal airport turnaround process in passenger-carriage service.Lithium-air batteries rely on oxidation of lithium to produce their current flow.