A system and method for providing feedback for an aircraft-bladed rotor about a longitudinal axis and having an adjustable blade pitch angle. At least one position marker is provided at the rotor, extends along an axial direction, from a first end to a second end, and has varying magnetic permeability from the first end to the second end. At least one sensor is coupled to the rotor and configured for producing, as the rotor rotates about the longitudinal axis, at least one sensor signal in response to detecting passage of the at least one position marker. A control unit is communicatively coupled to the at least one sensor and configured to generate a feedback signal indicative of the blade pitch angle in response to the at least one sensor signal received from the at least one sensor.

A method of forming a rotor blade, including forming at least one of a partial upper skin, a partial lower skin, and a partial support network using an additive manufacturing process; and forming a first receptacle in at least a one of the partial upper skin, the partial lower skin, and the partial support network using the additive manufacturing process. The first receptacle is configured to receive of at least one of an electronic component and a mechanical component. In some embodiments, there is a method of manufacturing a rotor blade that includes forming a first locating receptacle in at least one of the upper skin, the lower skin, and the support network using the additive manufacturing process; and positioning at least one of the upper skin, the lower skin, and the support network in a desired position on a fixture based, in part, on the first locating receptacle.

There is provided a blade angle feedback system for an aircraft-bladed rotor rotatable about a longitudinal axis and having an adjustable blade pitch angle. A feedback device is coupled to rotate with the rotor and to move along the axis with adjustment of the blade pitch angle. The feedback device comprises a body having position marker(s) embedded therein, the body made of a first material having a first magnetic permeability and the position marker(s) comprising a second material having a second magnetic permeability greater than the first. Sensor(s) are positioned adjacent the feedback device and configured for producing, as the feedback device rotates about the axis, sensor signal(s) in response to detecting passage of the position marker(s). A control unit is communicatively coupled to the sensor(s) and configured to generate a feedback signal indicative of the blade pitch angle in response to the sensor signal(s) received from the sensor(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 multi-material tip extension affixed at the tip end of the at least one rotor blade, wherein the multi-material tip extension comprises an inboard portion fabricated from a first material and an outboard portion fabricated from a second material, wherein the second material is different than the first material.

Aspects of the present disclosure provide coatings and methods for depositing coatings onto surfaces. In one aspect, a method for forming a coating includes applying a composition to a surface of a component, the composition including a first polymer, a second polymer that is a fluoropolymer, an isocyanate, and a curative. The method includes curing the mixture at a first temperature of about 50° C. or greater and increasing the first temperature to a second temperature of about 80° C. or greater. The method includes obtaining a coating disposed on the surface of the component, the coating having a thickness of from about 10 mils to about 50 mils and a void density of less than 5 voids of size 0.5 mm or greater per cm.sup.2.

A preceramic resin formulation comprising a polycarbosilane preceramic polymer, an organically modified silicon dioxide preceramic polymer, and, optionally, at least one filler. The preceramic resin formulation is formulated to exhibit a viscosity of from about 1,000 cP at about 25° C. to about 5,000 cP at a temperature of about 25° C. The at least one filler comprises first particles having an average mean diameter of less than about 1.0 μm and second particles having an average mean diameter of from about 1.5 μm to about 5 μm. Impregnated fibers comprising the preceramic resin formulation are also disclosed, as is a composite material comprising a reaction product of the polycarbosilane preceramic polymer, organically modified silicon dioxide preceramic polymer, and the at least one filler. Methods of forming a ceramic matrix composite are also disclosed.

A feedback device for use in a gas turbine engine, and methods and systems for controlling a pitch for an aircraft-bladed rotor, are provided. The feedback device is composed of a circular disk and a plurality of position markers. The circular disk is coupled to rotate with a rotor of the gas turbine engine, to move along a longitudinal axis of the rotor, and has first and second opposing faces defining a root surface that extends between and circumscribes the first and second faces. The plurality of position markers extend radially from the root surface, are circumferentially spaced around the circular disk, and extending along the longitudinal axis from a first end portion to a second end portion. At least part of the first end portion and/or of the second end portion comprises a material having higher magnetic permeability than that of a remainder of the position markers.

The present invention includes an apparatus for protecting an aerodynamic surface from erosion including a screen capable of being applied to a leading edge of the aerodynamic surface; and an erosion protection coating applied to the screen before or after the screen is applied to the leading edge, wherein the erosion protection coating protects the aerodynamic surface from erosion.

There is provided a blade angle feedback system for an aircraft-bladed rotor rotatable about a longitudinal axis and having an adjustable blade pitch angle. A feedback device is coupled to rotate with the rotor and to move along the axis with adjustment of the blade pitch angle. The feedback device comprises a body having position marker(s) embedded therein, the body made of a first material having a first magnetic permeability and the position marker(s) comprising a second material having a second magnetic permeability greater than the first. Sensor(s) are positioned adjacent the feedback device and configured for producing, as the feedback device rotates about the axis, sensor signal(s) in response to detecting passage of the position marker(s). A control unit is communicatively coupled to the sensor(s) and configured to generate a feedback signal indicative of the blade pitch angle in response to the sensor signal(s) received from the sensor(s).

A feedback device for use in a gas turbine engine, and methods and systems for controlling a pitch for an aircraft-bladed rotor, are provided. The feedback device is composed of a circular disk and a plurality of position markers. The circular disk is coupled to rotate with a rotor of the gas turbine engine, to move along a longitudinal axis of the rotor, and has first and second opposing faces defining a root surface that extends between and circumscribes the first and second faces. The plurality of position markers extend radially from the root surface and are circumferentially spaced around the circular disk. The position markers have a top surface elevated with respect to the root surface and opposing first and second side surfaces. The side surfaces of the position markers have a curved concave profile extending toward the root surface.