A landing gear includes a fixing mechanism, a driving mechanism disposed on the fixing mechanism, a translating member connected to the driving mechanism and configured to move relative to the fix mechanism whey being driven by the driving mechanism, and two supporting feet disposed opposite to each other. The two supporting feet are pivotally connected to the fixing mechanism and movably connected at two ends of the translating member. The driving mechanism is configured to drive the two supporting feet through the translating member to rotate relative to the fixing mechanism.

A public transportation system combines a unique combination of components that includes interoperable electric-powered vehicles, facilities, hardware and software having specifications, standards, processes, capabilities, nomenclature, and concepts of operations that together include a concerted, comprehensive, multi-modal, future system for moving people and goods that is herein named Quiet Urban Air Delivery (QUAD) and in which uniquely-capable, ultra-quiet, one to six-seat, electrically-powered, autonomous aircraft (SkyQarts) fly sub-193 kilometer trips on precise trajectories with negligible control latency and perform extremely short take-offs and landings (ESTOL) with curved traffic patterns at a highly-distributed network of very small, airports (“SkyNests”) that themselves have standardized compatible facilities that interoperate with SkyQarts as well as with versatile, autonomous electric-powered payload carts (EPCs) and robotic delivery carts (RDCs) to provide safe, fast, on-demand, community-acceptable, environmentally friendly, high-capacity, affordable door-to-door delivery of both passengers and cargo across urban, suburban and rural settings across the globe.

A public transportation system combines a unique combination of components that includes interoperable electric-powered vehicles, facilities, hardware and software having specifications, standards, processes, capabilities, nomenclature, and concepts of operations that together include a concerted, comprehensive, multi-modal, future system for moving people and goods that is herein named Quiet Urban Air Delivery (QUAD) and in which uniquely-capable, ultra-quiet, one to six-seat, electrically-powered, autonomous aircraft (SkyQarts) fly sub-193 kilometer trips on precise trajectories with negligible control latency and perform extremely short take-offs and landings (ESTOL) with curved traffic patterns at a highly-distributed network of very small, airports (“SkyNests”) that themselves have standardized compatible facilities that interoperate with SkyQarts as well as with versatile, autonomous electric-powered payload carts (EPCs) and robotic delivery carts (RDCs) to provide safe, fast, on-demand, community-acceptable, environmentally friendly, high-capacity, affordable door-to-door delivery of both passengers and cargo across urban, suburban and rural settings across the globe.

An emergency extension system for extending at least one aircraft undercarriage, the emergency extension system comprising both electromechanical actuators, each electromechanical actuator having an identification component arranged to allocate an identifier to said electromechanical actuator, which identifier depends in particular on a function performed by said electromechanical actuator, and also an electrical card having a delay component arranged to delay actuation of a the electromechanical actuator by an actuation delay that depends on the identifier allocated to the electromechanical actuator, the electromechanical actuators of the emergency extension system thus being arranged to be actuated in succession in an actuation sequence that is defined by the actuation delays.

An emergency extension system for extending at least one aircraft undercarriage, the emergency extension system comprising both electromechanical actuators, each electromechanical actuator having an identification component arranged to allocate an identifier to said electromechanical actuator, which identifier depends in particular on a function performed by said electromechanical actuator, and also an electrical card having a delay component arranged to delay actuation of a the electromechanical actuator by an actuation delay that depends on the identifier allocated to the electromechanical actuator, the electromechanical actuators of the emergency extension system thus being arranged to be actuated in succession in an actuation sequence that is defined by the actuation delays.

A levered landing gear including a first shock strut having a first end and a second end, a truck lever pivotally coupled to the second end of the first shock strut, and a second shock strut disposed between the second end of the first shock strut and the truck lever, where the second shock strut has a first end and a second end, the first end of the second shock strut being coupled to the second end of the first shock strut and the second end of the second shock strut being coupled to the truck lever.

A levered landing gear including a first shock strut having a first end and a second end, a truck lever pivotally coupled to the second end of the first shock strut, and a second shock strut disposed between the second end of the first shock strut and the truck lever, where the second shock strut has a first end and a second end, the first end of the second shock strut being coupled to the second end of the first shock strut and the second end of the second shock strut being coupled to the truck lever.

A nut locking assembly may comprise a pin, a nut, and a lock ring. The pin may include an outer diameter threaded surface and a plurality of radially inward extending grooves formed between the outer diameter threaded surface and an end of the pin. The nut may include an inner diameter threaded surface and a plurality of radially outward extending grooves formed between the inner diameter threaded surface and an axial end of the nut. The lock ring may include a plurality of outer diameter protrusions and a plurality of inner diameter protrusions.

A nut locking assembly may comprise a pin, a nut, and a lock ring. The pin may include an outer diameter threaded surface and a plurality of radially inward extending grooves formed between the outer diameter threaded surface and an end of the pin. The nut may include an inner diameter threaded surface and a plurality of radially outward extending grooves formed between the inner diameter threaded surface and an axial end of the nut. The lock ring may include a plurality of outer diameter protrusions and a plurality of inner diameter protrusions.

A method of determining a service interval for an actuator of a landing gear assembly is suitable for used with a landing gear assembly in which the actuator positions the landing gear assembly between a stowed position and a deployed position. The method includes the steps of determining an actuator travel value for a time interval and increasing a total actuator accumulated travel value by the actuator travel value for the time interval. The method further includes the step of comparing the total actuator accumulated travel value to a predetermined value.