A linkage assembly configured for use on a rotor blade having a first section and a second section, the second section being configured to rotate about a blade fold axis between an aligned position and a rotated position relative to the first section is provided. The linkage assembly includes a bracket having a first portion rotatably coupled to the first section about the blade fold axis and a second portion mounted to the second section. A spacer assembly is positioned between the bracket and an adjacent wall of the second section. The overall thickness of the spacer assembly is adjustable to control a distance between the second section and the bracket to adjust the rotated position.

The blade support apparatus involves storing and transporting helicopter blades until the blades are needed for reassembly to the helicopter. The blade support apparatus comprises a lid, a container, a root attachment, and a plurality of attachment bars. One end of the helicopter blade is the root. The blade root is secured to the root plug. A multiplicity of supports secure the container to a transport. The height and angle of each blade in the container can be adjusted, enabling them to conform to the blade curvature which spirals from the blade root to the tip of the blade. Height adjustment to a helicopter blade is achieved by a plurality of contoured pads mounted in the container at varying points along the helicopter blade. Angle adjustment is achieved by a plurality of pivot supports mounted in the container at varying points along the helicopter blade.

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.

One embodiment is a rotor system comprising a rotor duct; at least one rotor blade, wherein the at least one rotor blade comprises an outboard end; a tip extension mechanism affixed at the outboard end of the at least one rotor blade, wherein the tip extension mechanism comprises at least one shim, the at least one rotor blade with the tip extension mechanism affixed thereto comprising an extended rotor blade; and a blade tip affixed to an outboard end of the extended rotor blade, wherein the blade tip is affixed to the extended rotor blade via at least one removable fastener.

A gas turbine engine for an aircraft, includes: an engine core having a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan assembly located upstream of the engine core; and a gearbox receiving an input from the core shaft and outputs drive to the fan assembly so as to drive the fan assembly at a lower rotational speed than the core shaft, wherein the fan assembly has fan blades mounted around a hub, the fan blades having blade tips defining an outer diameter of the fan assembly of from around 220 cm to around 400 cm, the hub having slots located around a rim of the hub, each slot receiving a root of a corresponding fan blade, wherein a ratio of a mass of the hub to a total mass of the fan blades is within the range of around 0.45 to around 0.7.

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

A method of mounting a replacement tip section to an exposed end of a rotor blade includes removing an existing tip section from the rotor blade to create the exposed end of the rotor blade, installing the rotor blade having the exposed end onto a holding fixture, assembling the replacement tip section about the exposed end of the rotor blade, positioning a bonding fixture about the replacement tip section, and curing the replacement tip section to the exposed end of the rotor blade.

A propeller includes a blade. The blade includes a blade root, a blade tip disposed away from the blade root, a blade front surface, and a blade back surface. The blade also includes a front edge connecting a first side of each of the blade front surface and the blade back surface. The blade also includes a rear edge connecting a second side of each of the blade front surface and the blade back surface. The blade further includes a first suppression member formed by a portion of the front edge adjacent to the blade tip bending toward a first direction. The first direction is a direction from the front edge to the rear edge. The first suppression member is configured to suppress a spanwise air flow.

A propeller includes a blade. The blade includes a blade root, a blade tip disposed away from the blade root, a blade front surface, and a blade back surface. The blade also includes a front edge connecting a first side of each of the blade front surface and the blade back surface. The blade also includes a rear edge connecting a second side of each of the blade front surface and the blade back surface. The blade further includes a first suppression member formed by a portion of the front edge adjacent to the blade tip bending toward a first direction. The first direction is a direction from the front edge to the rear edge. The first suppression member is configured to suppress a spanwise air flow.

The invention relates to an aircraft with a longitudinal central axis, comprising: a fuselage structure (2) which is designed to accommodate persons and/or payload; a wing structure (3) which has at least two wing halves (3.1) which are attached to the fuselage structure (2) and which have a fuselage-side main region (H) and a tip region (S); at least one forward propulsion unit (4) which is designed to generate a forward force, acting in the direction of the central axis, on the aircraft; at least four lifting propulsion units (5) which are designed to generate a lift force, acting in the direction of the central axis, on the aircraft.