A propulsion system is provided, including a first propulsion unit, a second propulsion unit, a rotor, a first coupling and a second coupling. The first propulsion unit is configured for being fixedly mounted to an airframe. The rotor is configured for being pivotably mounted with respect to the first propulsion unit to allow selectively pivoting of the rotor from a horizontal mode to a vertical mode. The first coupling is configured for selectively coupling and decoupling the rotor with respect to the first propulsion unit. The second coupling is configured for selectively coupling and decoupling the rotor with respect to the second propulsion unit, independently of the first coupling.

In one aspect, there is provided a rotary blade movement system including a retaining member configured to receive a rotor blade, a graspable arm, and a coupling mechanism operable to removably couple the retaining member to the graspable arm. The rotor blade movement system is configured to enable a user to adjust the position of the rotor blade by moving the graspable arm. The coupling mechanism can be a ball and socket joint. In one aspect, there is a method of rotating a rotor blade using a rotary blade movement system.

An aircraft includes a fuselage and an engine housed in the fuselage. A ram-air engine inlet is formed on an exterior of the fuselage. The ram-air engine inlet is defined, at least in part, by a cowling door. The cowling door is moveable between a closed position and an open position. An intake duct fluidly couples the ram-air engine inlet to the engine. A filter is disposed across the intake duct. A bypass duct is formed in the ram-air engine inlet aft of the intake duct. The bypass duct is operable to be selectively opened and closed.

An aircraft includes a fuselage and an engine housed in the fuselage. A ram-air engine inlet is formed on an exterior of the fuselage. The ram-air engine inlet is defined, at least in part, by a cowling door. The cowling door is moveable between a closed position and an open position. An intake duct fluidly couples the ram-air engine inlet to the engine. A filter is disposed across the intake duct. A bypass duct is formed in the ram-air engine inlet aft of the intake duct. The bypass duct is operable to be selectively opened and closed.

A ducted-rotor aircraft includes a fuselage, one or more ducts, and a spindle that rotatably couples the one or more ducts to the fuselage. Each duct includes a hub that is configured to support a rotor, a plurality of stators that are coupled to the hub, a duct ring that is coupled to the plurality of stators, and a fitting that is coupled to a first stator of the plurality of stators. The fitting has a tubular collar that defines a first aperture that extends through the fitting. The collar is configured to receive a portion of the spindle. The first stator includes a rib that is spaced inward from the fitting and that defines a second aperture that is aligned with the first aperture and that is configured to receive an end of the spindle.

A ducted-rotor aircraft includes a fuselage, one or more ducts, and a spindle that rotatably couples the one or more ducts to the fuselage. Each duct includes a hub that is configured to support a rotor, a plurality of stators that are coupled to the hub, a duct ring that is coupled to the plurality of stators, and a fitting that is coupled to a first stator of the plurality of stators. The fitting has a tubular collar that defines a first aperture that extends through the fitting. The collar is configured to receive a portion of the spindle. The first stator includes a rib that is spaced inward from the fitting and that defines a second aperture that is aligned with the first aperture and that is configured to receive an end of the spindle.

A system includes an electric motor. A drive shaft is connected to be driven by the electric motor. A propulsor is connected to be driven by the shaft. The propulsor is configured to pivot to a first orientation configured to produce lift when the motor rotates the shaft in a first direction, and to pivot to a second orientation configured to produce thrust when the motor rotates the shaft in a second direction that is opposite of the first direction.

An aerial vehicle adapted for vertical takeoff and landing using pivoting thrust producing elements for takeoff and landing. An aerial vehicle which is adapted to takeoff with thrust units providing vertical thrust and then transitioning to a horizontal flight path. An aerial vehicle with pivoting thrust units with propellers, wherein some or all of the propellers are able to be stowed and fully nested during forward flight.

An aerial vehicle adapted for vertical takeoff and landing using pivoting thrust producing elements for takeoff and landing. An aerial vehicle which is adapted to takeoff with thrust units providing vertical thrust and then transitioning to a horizontal flight path. An aerial vehicle with pivoting thrust units with propellers, wherein some or all of the propellers are able to be stowed and fully nested during forward flight.

An engine mount assembly for coupling an engine to an airframe includes a torsion bar, a lateral movement control assembly and a vertical movement control assembly. The torsion bar has a torsional stiffness and is coupled between the engine and the airframe such that torsional movement of the engine causes torsion in the torsion bar. The lateral movement control assembly has a lateral stiffness and is coupled between the torsion bar and the airframe such that lateral movement of the engine causes rotation of the torsion bar which reacts on lateral movement control assembly. The vertical movement control assembly has a vertical stiffness and is coupled between the engine and the airframe such that vertical movement of the engine reacts on the vertical movement control assembly. The engine mount assembly, thereby enables torsional, lateral and vertical movement of the engine to be independently controlled.