A tip gap control system for a ducted aircraft includes a flight control computer including an inner duct surface control module configured to generate an inner duct surface actuator command and a proprotor system in data communication with the flight control computer. The proprotor system includes a duct having active inner duct surfaces movable into various positions including a retracted position and an extended position. The proprotor system also includes proprotor blades surrounded by the duct and one or more actuators coupled to the active inner duct surfaces. The one or more actuators move the active inner duct surfaces between the various positions based on the inner duct surface actuator command, thereby controlling a tip gap between the proprotor blades and the duct.

A propeller having a means for creating fluid flow in a non-axial direction and redirecting it in an axial direction.

A propeller having a means for creating fluid flow in a non-axial direction and redirecting it in an axial direction.

A rotating system comprising two or more blades 3 mounted on a hub installed on a rotatable propeller shaft 1, each blade provided with a respective sensor 4 arranged to detect response of the respective blade to harmonic excitation; and the system further comprising means configured to compare the response of the respective blade to that of the other blade(s).

A rotating system comprising two or more blades 3 mounted on a hub installed on a rotatable propeller shaft 1, each blade provided with a respective sensor 4 arranged to detect response of the respective blade to harmonic excitation; and the system further comprising means configured to compare the response of the respective blade to that of the other blade(s).

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.

An airfoil that includes an airfoil body having a root and a tip, and convex and concave sides that extend between a leading edge and a trailing edge. The airfoil also includes at least a first cladding element that is attached to the airfoil body. The first cladding element includes a first portion and a second portion. The second portion is configured to separate from the first portion when the first cladding element encounters a force of at least a predetermined amount.

A propeller system including a propeller including a central attachment member and a plurality of blade apparatuses, each including a blade body attached to the central attachment member and a magnetic coupling member attached to a radially outward end of the blade body. The propeller system further comprises a propeller frame configured to at least partially circumscribe the magnetic coupling member of each blade apparatus and a plurality of electromagnets positioned on the propeller frame and operable to generate magnetic fields to suspend the magnetic coupling members, laterally translate the magnetic coupling members, rotate the magnetic coupling members along the radial axis of the propeller system, thereby rotating the blade bodies.

A leading edge structure for an aerodynamic surface of an aircraft with an outer wall part curved in a streamlined manner around an interior compartment and having an inner surface pointing toward the interior compartment and an outer surface provided for contact with the external surrounding flow. The outer wall part has a first outer wall section extending from a leading edge point in an incident flow direction in a convexly curved manner in the direction of a first side. The outer wall part has a second outer wall section which extends from the leading edge point in the incident flow direction in a convexly curved in the direction of a second side. An inner wall part is arranged in the interior compartment opposite the inner surface of the outer wall part and extends from the first outer wall section to the second outer wall section.

A proprotor system for a ducted aircraft includes a duct and proprotor blades surrounded by the duct. Each proprotor blade is rotatable about a respective pitch change axis. The proprotor blades are configured to change collective pitch about the pitch change axes. The proprotor blades are extendable along the pitch change axes into various positions including a retracted position and an extended position. The proprotor blades change between the retracted position and the extended position based on the collective pitch of the proprotor blades, thereby controlling a tip gap between the proprotor blades and the duct.