An autonomous propeller propulsion system for an aircraft. The autonomous system comprises a chassis with first attachment systems which engage with second attachment systems of the wing to ensure detachable attachment of the autonomous system, a fuel cell attached to the chassis, an electric motor attached to the chassis and having an output shaft, a propshaft rotated by the output shaft, a propeller attached to the propshaft, a controller converting an electric current delivered by the fuel cells into an electric current delivered to the electric motor, a hydrogen feed duct and an air feed duct, a set of auxiliary equipment, and a first connection arrangement, which connects with a second connection arrangement of the aircraft.

According to one implementation of the present disclosure, a stabilizer of an aircraft includes an energy attenuating portion. The energy attenuating portion includes first and second edge sections separated by an adaptable section. The adaptable section may be rigid in a first range of directions and compressible in a second range of directions.

A tiltrotor aircraft is designed to accommodate rotors of different diameters, as well as corresponding wings and fuselages with different span and length, while maintaining very high parts commonality, especially with respect to drive train and power source. This enables design and operation of a fleet of such aircraft with significantly different rotor diameters, which are nevertheless optimized for different missions. In preferred embodiments the rotors are configured to have high stiffness and low weight to reduce aero-structural dynamic issues across the fleet. Also in preferred embodiments drive systems are designed for a full range of speed, torque, and power associated with all intended rotors. Turboshaft engine speeds are restricted to a narrow RPM range, so that a single gearset can be replaced to achieve the desired rotor RPM. Also in preferred embodiments, aircraft in a fleet can differ in folded length, empty weight, payload length by up 50%.

A leading edge (3) of a control surface (1) for an aircraft includes a balance weight (6) attached to the forward-most region of the leading edge (3). The control surface (1) rotates with respect to the stabilizer (2) around a hinge line (5). The balance weight (6) is ahead of and adjacent to the most frontal portion (7) of the leading edge (3) of the control surface (1) are is inside the trailing edge of the stabilizer (2). This arrangement allows to have an anti-flutter balance weight without any impact in aerodynamic drag.

A leading edge (3) of a control surface (1) for an aircraft includes a balance weight (6) attached to the forward-most region of the leading edge (3). The control surface (1) rotates with respect to the stabilizer (2) around a hinge line (5). The balance weight (6) is ahead of and adjacent to the most frontal portion (7) of the leading edge (3) of the control surface (1) are is inside the trailing edge of the stabilizer (2). This arrangement allows to have an anti-flutter balance weight without any impact in aerodynamic drag.

Airframe localized keel structures are disclosed. An example aircraft includes an airframe, a first engine mounted on a first side of the airframe, a second engine mounted on a second side of the airframe, and an airframe keel positioned on at least one of a lower portion of the airframe or an upper portion of the airframe between the first engine and the second engine, the airframe keel to prevent an object from exiting the first engine and impacting the second engine.

Airframe localized keel structures are disclosed. An example aircraft includes an airframe, a first engine mounted on a first side of the airframe, a second engine mounted on a second side of the airframe, and an airframe keel positioned on at least one of a lower portion of the airframe or an upper portion of the airframe between the first engine and the second engine, the airframe keel to prevent an object from exiting the first engine and impacting the second engine.

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.

Provided is a supersonic aircraft including: a shield that shields an engine exhaust flow discharged from a jet engine accommodated in an engine nacelle mounted on a fuselage of the aircraft to thereby reduce sonic booms due to the engine exhaust flow; and an exhaust nozzle that is provided in an exhaust port of the engine nacelle and that generates a sound source for high-frequency components at a position at which the shield is capable of shielding the high-frequency components of the engine exhaust flow, to thereby reduce jet noise having the high-frequency components, and promotes mixing of the engine exhaust flow that generates low-frequency noise components with an external air flow to thereby reduce jet noise having the low-frequency components.