Abstract: A dual-motor system includes a first motor rotationally coupled to a first drive shaft. The first drive shaft is coupled to a common shaft couplable to a rotationally driveable member. The dual-motor system also includes a second motor rotationally coupled to a second drive shaft. The second drive shaft is coupled to the common shaft. The first motor and the second motor are coaxially aligned with the first drive shaft passing through the second drive shaft.

Abstract: An exemplary tiltrotor aircraft having a vertical takeoff and landing (VTOL) flight mode and a forward flight mode includes tiltable rotors located at forward boom ends, tiltable ducted fans located at wings aft of the forward boom ends, and aft rotors located on aft boom portions.

Abstract: One embodiment is an aircraft operable in a hover mode and a cruise mode and including a fuselage; wings connected on opposite sides of the fuselage; a canard connected to the fuselage forward of the wings; forward propulsion systems connected to a trailing edge of the canard on opposite sides of the fuselage; aft propulsion systems connected to trailing edges of the wings; and wing-mounted propulsion systems connected to leading edges of the wings. The aft propulsion systems are tiltable between a first position when the aircraft is in the hover mode and a second position when the aircraft is in the cruise mode. Each of the propulsion systems includes a rotor assembly comprising a plurality of rotor blades. The propulsion systems are substantially equidistant from a center of gravity (CG) of the aircraft.

Abstract: Embodiments include an aircraft comprising a fuselage; a wing connected to the fuselage; and first and second propulsion systems connected to the wing on opposite sides of the fuselage, wherein at least a portion of each of the first and second propulsion systems and at least a portion of the wing are tiltable between a first position in which the aircraft is in a hover mode and a second position in which the aircraft is in a cruise mode, wherein each of the propulsion systems includes pylon and a rotor assembly comprising a plurality of rotor blades.

Abstract: Embodiments include an aircraft comprising a fuselage; a wing connected to the fuselage; and first and second propulsion systems connected to the wing on opposite sides of the fuselage, wherein at least a portion of each of the first and second propulsion systems and at least a portion of the wing are tiltable between a first position in which the aircraft is in a hover mode and a second position in which the aircraft is in a cruise mode, wherein each of the propulsion systems includes pylon and a rotor assembly comprising a plurality of rotor blades.

Abstract: A dual-motor system includes a first motor rotationally coupled to a first drive shaft. The first drive shaft is coupled to a common shaft couplable to a rotationally driveable member. The dual-motor system also includes a second motor rotationally coupled to a second drive shaft. The second drive shaft is coupled to the common shaft. The first motor and the second motor are coaxially aligned with the first drive shaft passing through the second drive shaft.

Abstract: An exemplary dual motor input includes a common shaft for coupling to a member to be rotationally driven, a first motor rotationally coupled to a first drive shaft, the first drive shaft coupled to the common shaft, and a second motor rotationally coupled to a second drive shaft, the second drive shaft coupled to the common shaft.

Abstract: An aircraft includes fuselage, a seat, and battery compartment. Fuselage extends along a longitudinal axis. Seat is configured to support a passenger. The battery compartment that includes a battery configured to provide power to propel the aircraft. The battery compartment, including the battery, is located laterally adjacent to the seat along the longitudinal axis.

Abstract: Embodiments include an aircraft comprising a fuselage; a wing connected to the fuselage; and first and second propulsion systems connected to the wing on opposite sides of the fuselage, wherein at least a portion of each of the first and second propulsion systems and at least a portion of the wing are tiltable between a first position in which the aircraft is in a hover mode and a second position in which the aircraft is in a cruise mode, wherein each of the propulsion systems includes pylon and a rotor assembly comprising a plurality of rotor blades.

Abstract: One embodiment is an aircraft including a fuselage; a wing connected to the fuselage; first and second booms connected to the wing on opposite sides of the fuselage; first and second forward propulsion systems attached to forward ends of the first and second booms; first and second aft propulsion systems fixedly attached proximate aft ends of the first and second booms; and first and second wing-mounted propulsion systems connected to outboard ends of wings; wherein the first and second wing-mounted propulsion systems are tiltable between a first position when the aircraft is in a hover mode and a second position when the aircraft is in a cruise mode.

Abstract: One embodiment is an aircraft including a fuselage; a wing connected to the fuselage; first and second booms connected to the wing on opposite sides of the fuselage; first and second forward propulsion systems attached to forward ends of the first and second booms; first and second aft propulsion systems fixedly attached proximate aft ends of the first and second booms; first and second wing-mounted propulsion systems connected to outboard ends of wings; and first and second wing tips fixedly connected to outboard sides of the first and second wing-mounted propulsion systems; wherein the first and second wing-mounted propulsion systems and the first and second wing tips are collectively tiltable between a first position when the aircraft is in a hover mode and a second position when the aircraft is in a cruise mode.

Abstract: One embodiment is an aircraft operable in a hover mode and a cruise mode and including a fuselage; wings connected on opposite sides of the fuselage; a canard connected to the fuselage forward of the wings; forward propulsion systems connected to a trailing edge of the canard on opposite sides of the fuselage; aft propulsion systems connected to trailing edges of the wings; and wing-mounted propulsion systems connected to leading edges of the wings. The aft propulsion systems are tiltable between a first position when the aircraft is in the hover mode and a second position when the aircraft is in the cruise mode. Each of the propulsion systems includes a rotor assembly comprising a plurality of rotor blades. The propulsion systems are substantially equidistant from a center of gravity (CG) of the aircraft.

Abstract: An aircraft includes fuselage, a seat, and battery compartment. Fuselage extends along a longitudinal axis. Seat is configured to support a passenger. The battery compartment that includes a battery configured to provide power to propel the aircraft. The battery compartment, including the battery, is located laterally adjacent to the seat along the longitudinal axis.

Abstract: A vertical takeoff and landing aircraft is described in which rotors can be disposed underneath the booms. This will allow for zero downward force resulting from thrust on the aircraft and therefore greater energy efficiency. Retractable doors can shield the rotors when not in use, decreasing drag during forward flight.

Abstract: A rotor system is provided in one example embodiment and may include a rotor duct; at least one rotor blade, wherein the at least one rotor blade comprises a tip end; and a tip extension affixed at the tip end of the at least one rotor blade, wherein the tip extension comprises a plurality of flexible elements and the rotor blade has a fixed extended length based on the tip extension. The tip extension may provide a clearance distance between the tip extension and the rotor duct.

Abstract: A rotor system is provided in one example embodiment and may include a rotor duct; at least one rotor blade, wherein the at least one rotor blade comprises a tip end; and a tip extension affixed at the tip end of the at least one rotor blade, wherein the tip extension is comprised, at least in part, of a flexible material and the rotor blade has a fixed extended length based on the tip extension. The tip extension may provide a clearance distance between the tip extension and the rotor duct.

Abstract: An exemplary tiltrotor aircraft having a vertical takeoff and landing (VTOL) flight mode and a forward flight mode includes tiltable rotors located at forward boom ends, tiltable ducted fans located at wings aft of the forward boom ends, and aft rotors located on aft boom portions.

Abstract: An exemplary tail rotor includes a first blade assembly configured to rotate in a first direction about an axis of rotation and a second blade assembly configured to rotate in a second direction about the axis of rotation.

Abstract: An exemplary ducted fan with an optimized stator includes a duct surrounding a rotor hub from which blades radially extend and the stator having a stator span extending horizontally across an inside diameter of the duct, the stator having a stator chord extending from a leading edge to a trailing edge, wherein a length of the stator chord varies across the stator span.

Abstract: An exemplary tiltrotor aircraft having a vertical takeoff and landing (VTOL) flight mode and a forward flight mode includes tiltable rotors located at forward boom ends, tiltable ducted fans located at wings aft of the forward boom ends, and aft rotors located on aft boom portions.