Abstract: In one example, the disclosure is directed to a method of determining a length of a wear pin in a brake assembly. The method includes obtaining an input image of a portion of the brake assembly, such as with a camera. The input image includes the wear pin and a reference object, and the reference object has a known dimension. A processor may determine, based on the input image, an image dimension of the reference object. The processor may determine, based on the input image, an image dimension of the wear pin. The processor may further determine, based on the image dimension of the reference object, the image dimension of the wear pin, and the known dimension of the reference object, an estimated measurement of the dimension of the wear pin.

Abstract: A method for making a carbon-carbon composite brake disc by infiltrating a porous carbon preform with a resin and carbonizing the resin-infiltrated preform at a high pressure of at least about 5,000 psi to form a densified carbon-carbon composite disc brake with a final density of at least about 1.9 g/cc. The porous carbon preform includes a plurality of fabric sheets having non-woven oxidized polyacrylonitrile fibers, pitch fibers, or rayon fibers and a basis weight in the range from about 1250 to about 3000 grams per square meter. The fabric sheets are needled together. The porous carbon preform is infiltrated with resin, which includes at least one of an isotropic resin or a mesophase resin.

Abstract: In one example, the disclosure is directed to a method of determining a length of a wear pin in a brake assembly. The method includes obtaining an input image of a portion of the brake assembly, such as with a camera. The input image includes the wear pin and a reference object, and the reference object has a known dimension. A processor may determine, based on the input image, an image dimension of the reference object. The processor may determine, based on the input image, an image dimension of the wear pin. The processor may further determine, based on the image dimension of the reference object, the image dimension of the wear pin, and the known dimension of the reference object, an estimated measurement of the dimension of the wear pin.

Abstract: A system method of estimating health of aircraft brake system friction material includes sensing a temperature of the friction material, and supplying the sensed temperature to a processor-implemented thermal model that is configured to estimate friction material temperatures at one or more locations on the friction material. The estimates of friction material temperatures are supplied to a processor-implemented thermal oxidation model that is configured, based on the estimates of friction material temperatures, to estimate friction material loss due to thermal oxidation. Data representative of runway fluid exposure are supplied to a processor-implemented catalytic oxidation model that is configured, based on the runway fluid exposure, to estimate friction material loss due to catalytic oxidation. The health of the friction material is estimated based on the estimates of friction material loss from the processor-implemented thermal oxidation model and the processor-implemented catalytic oxidation model.

Abstract: In one example, a method for forming a densified carbon-carbon composite material comprises infiltrating a carbon fiber preform with a monomer mixture for a condensed polynuclear aromatic (COPNA) resin; polymerizing and crosslinking the monomer mixture within the carbon fiber preform to form a crosslinked COPNA by subsequently heating the carbon fiber preform infiltrated with the monomer mixture to a polymerization temperature of the COPNA resin; and carbonizing the crosslinked COPNA resin within the carbon fiber preform by heating the crosslinked COPNA resin to a carbonization temperature to form the densified carbon-carbon composite material, wherein the carbonization temperature is greater than the polymerization temperature.

Abstract: A system method of estimating health of aircraft brake system friction material includes sensing a temperature of the friction material, and supplying the sensed temperature to a processor-implemented thermal model that is configured to estimate friction material temperatures at one or more locations on the friction material. The estimates of friction material temperatures are supplied to a processor-implemented thermal oxidation model that is configured, based on the estimates of friction material temperatures, to estimate friction material loss due to thermal oxidation. Data representative of runway fluid exposure are supplied to a processor-implemented catalytic oxidation model that is configured, based on the runway fluid exposure, to estimate friction material loss due to catalytic oxidation. The health of the friction material is estimated based on the estimates of friction material loss from the processor-implemented thermal oxidation model and the processor-implemented catalytic oxidation model.

Abstract: A case assembly for an aircraft is provided. The assembly includes a thrust reverser actuation system (TRAS) configured to provide braking assistance to the aircraft; a variable area fan nozzle (VAFN) system configured to adjust an engine exhaust of the aircraft; and a common control group coupled to the TRAS and the VAFN system for controlling operation of the TRAS and the VAFN system.

Abstract: An electro-hydraulic servo valve (61) is provided, which includes a torque motor (63) and a position sensor (37) attached to a housing (67) of the electro-hydraulic servo valve (61). A spool valve (69) is disposed within a bore (71) of the housing (67) and is connected to the torque motor (63) such that it can move linearly within the bore (71) of the housing (67). The position sensor (37) determines the position of the spool valve (69) within the bore (71), and extends through the housing (67) such that it is connected to the spool valve (69) perpendicularly to the linear movement of the spool valve (69).