Abstract: A carbon deposit inhibiting thermal barrier coating for an internal element or component in a gas turbine engine. Such coating includes a layer of thermal barrier material coated onto the surface of an engine component that will be exposed to the flow of burning engine gases. Such coating further includes a layer of carbon deposit inhibiting material coated on top of the layer of thermal barrier material.

Abstract: A coupling with a tribological system that can withstand temperatures up to 600° C. The coupling includes a shaft having an outer surface with a layer of chromium and a sleeve for receiving the shaft. The sleeve has an inner surface with a layer of silver or gold. The silver or gold layer contacts the chromium layer to form the tribological system.

Abstract: A system and method of supplying temperature-controlled air to an aircraft environmental control system during ground support operations that uses a bypass valve in a bypass line to control the amount of cooling air flowing through a heat exchanger. The heat exchanger removes heat from a flow of compressed air supplied to the air conditioning unit and supplies cooled compressed air at a desired temperature. The temperature of the cooled compressed air is controlled by selectively positioning the bypass valve, which regulates cooling air flow through the heat exchanger.

Abstract: An apparatus and system for thermally isolating a gas turbine housing from the significantly high temperatures associated with the combustion gases flowing through the housing. A floating liner is assembled within the housing with an outer baffle surrounding the floating liner and an inner baffle disposed within the floating liner. The floating liner creates a thermally isolated device to cover and protect the housing from high temperature. Openings formed in the outer baffle, floating liner and inner baffle create a single, continuous cooling passageway within the housing for collecting heat from adjacent the surfaces of the floating liner and expelling the heat into the combustion exhaust stream.

Abstract: A method and a system is provided, useable in electrical control sensors for shaft speed signal frequency change rate tests, detecting intermittent or “in-range” failures. The method estimates a short-term variance (standard deviation) of the measured signal or signal rate of change, using the equation: Var[x]=E[x2]−E2[x], where E[x2] is an estimated average of the squared measured signal or rate of change over the short term, and E2[x] is a squared estimated average of the measured signal or rate of change over the short term. The estimated variance is compared with a predefined variance limit for a predefined amount of time, and if the estimated variance exceeds the predefined variance limit for the predefined amount of time, the measured signal is deemed invalid. A latching counter is used for timing, and its time out rate is preferably proportional to the time period the measured input is true.

Abstract: A terminal assembly for rotating electrical machines, such as high speed starter-generators used for gas turbine engines in aircraft or other vehicles, is made from components that are readily assembled for ease of installation, maintenance, and repair. The terminal assembly includes a feedthrough body, an electrically conductive electrode that extends through the feedthrough body, and a hermetical seal that couples the electrode to the feedthrough body inner surface.

Abstract: The jacking plate may be used to reinforce structural assembly elements that may be required to withstand the force of the use of a jack bolt to separate assembly elements. The jacking plate may be attached intermediate one structural element and a nut plate. A bushing may be attached in a second structural element through which bushing the jack bolt is threaded to apply force against the jacking plate. The jacking plate may be constructed of a hardened metal such as stainless steel to inhibit deforming of the structural element and nut plate.

Abstract: An air turbine starter with an improved seal assembly is provided. A fluid conduit or channel allows higher pressure fluid into one side of a bearing seal. For example, the seal assembly may include a face seal, and a second seal forming a chamber therebetween and a flow passage opens into the chamber for exposing the chamber to the higher pressure.

Abstract: A method and an engine monitoring and control system is provided. The system includes a tested unit having a symbol table with addresses of monitored and controlled parameters, an external portable personal computer having a memory, a display and a graphical user interface (GUI) responsive to user commands, and a communication link between the tested unit and the personal computer. The GUI is used for creating a customized set of application-specific GUI display pages with icons and text, for displaying received parameter values, and for selecting commands and parameters from the displayed pages. The computer executes a monitoring software program including a set of computer-executable program instructions for retrieving the tested unit parameter values and controlling the tested unit performance.

Abstract: A method of casting a metal article comprising the steps of forming a mold having a mold cavity with a height, a thinwall portion and a base wall portion. The thinwall portion may be less than 0.05 inches thick and free of gating. The method comprises the steps of: positioning the mold in a preheated furnace so that the furnace substantially surrounds the mold and so that a longitudinal axis of the long thin portion of the mold cavity is in an upright orientation; heating the mold in the furnace to a temperature between 1045° C. and 1055° C.; and drawing a vacuum in the furnace. The metal is heated until it is molten and is then poured at a temperature between 1560° land 1570° C. into the mold cavity. The vacuum is then broken and the mold cavity withdrawn from the furnace. The molten metal is allowed to solidify in the mold cavity so that it will solidify with a equiaxed grain structure.

Abstract: A tortuous path quiet exhaust eductor system may be mounted to a gas turbine engine, such as commercial aircraft APU. The system includes an oil cooler, eductor primary nozzle, oil cooler air nozzle, and surge air dump nozzle. The primary nozzle, oil cooler air nozzle, and surge air dump nozzle direct exhaust flow to entrain APU compartment cooling air, oil cooling air and surge air in a direction having both radial and axial components with respect to the APU centerline axis. The exhaust flow is directed into an eductor mixing duct angled away from the centerline axis and then is turned to enter an exit duct angled toward the centerline axis so that direct line of sight acoustic paths from the tail pipe exit to the turbine exit are blocked, suppressing core noise. The tail pipe ducts may be acoustically treated, further enhancing noise suppression.

Abstract: A system and method is provided that employs schedules and gains in an electronic control unit for a gas turbine engine which are independent of fuel type used to run the engine. According to one embodiment, the method comprises the steps of determining engine requirements and calculating a desired energy flow for at least one engine, maintaining desired engine conditions according to the desired energy flow; converting the desired energy flow into expected fuel flow according to the specific fuel being utilized, calculating a fuel flow command, and communicating the fuel flow command to at least one fuel valve.

Abstract: The broken shaft detection system and method uses a detector assembly mounted downstream of a power turbine wheel of a gas turbine engine to detect rearward axial motion of the wheel and thereby a broken shaft event. The detector assembly has a plunger positioned to be axially displaced against a link connected in an electrical circuit. The link may be broken when the plunger is displaced thereby creating an open circuit that may be detected by a detection and test element. The breaking may be communicated to an overspeed circuit that controls a shut off switch that interrupts fuel flow to the engine. The link may be connected to the detection and test element by two pairs of parallels wires to facilitate monitoring of circuit function and to detect failures that are not broken shaft event failures.

Abstract: A nickel base single crystal compliant layer on a ceramic blade has the capability to sustain high stresses and high operating temperature. Layers of nickel and platinum bonded on a single crystal superalloy over a sputtered gold-chromium layer support the high stress levels at elevated temperature without extrusion of the soft platinum or nickel layer and without destruction of an NiO compliant surface. The compliant layers have survived stress and temperature conditions without failure to the ceramic blade and the system can be stressed/heated and unloaded/cooled repeatedly without damage to the ceramic blades. A single crystal nickel base superalloy (i.e., SC180) has high strength properties at elevated temperature. Thin layers of chromium followed by gold are e-beam evaporated on one side of a polished surface of the alloy. Pure nickel is electroplated over this e-beam gold-chromium layer. Platinum is either electroplated or plated electrolessly over the nickel layer.

Abstract: A built-in test system for aircraft indication switches comprises a plurality of aircraft indication switches and a first resistor adding network having input resistors individually connected to first contacts of different ones of the indication switches. The test system further includes a second resistor adding network having input resistors individually connected to second contacts of different ones of the indication switches. Output circuitry is provided for coupling outputs of the first and second resistor adding networks to an electronic control unit for the aircraft.

Abstract: A thermal barrier coating for nickel based superalloy articles such as turbine engine vanes and blades that are exposed to high temperature gas is disclosed. The coating includes a columnar grained ceramic layer applied to a platinum modified Ni3Al gamma prime phase bond coat having a high purity alumina scale. The preferred composition of the bond coat is 5 to 16% by weight of aluminum, 5 to 25% by weight of platinum with the balance, at least 50% by weight, nickel. A method for making the bond coat is also disclosed.

Abstract: A gas turbine engine having a housing and an axially extending shaft journaled to the housing by two axially spaced apart bearings. The bearings are located along the shaft so as to define an overhung shaft portion. A rotating component such as a turbine wheel or compressor wheel is mounted on the overhung shaft portion and is concentric about the centerline (50) of the engine. An annular shroud (40) that is part of the housing is disposed about the rotating component, the annular shroud (40) being concentric about a centerline (60) radially offset from the engine (50).

Abstract: For regulating engine exhaust and for environmental reasons, aircraft users are restricted from expelling engine fluids from engines onto airport ramps. All such fluid must be collected and subsequently burned or properly disposed of. The present invention installs witness drain valves in the drain lines between seal cavities and environmental collector tank. The witness drain valves have a small reservoir that will retain a known volume of fluid. As fluid passes from a leaking seal to the collector tank, a small sample is captured in the witness drain valve. Once the witness drain valve reservoir is full, the leaking fluid then flows on to a collector tank, which is also provided. During regular engine maintenance, technicians push on a spring loaded drain valve located on the witness drain valve reservoir. If fluid is detected, the seal is beginning to leak, and corrective maintenance may be scheduled while the leak rate is still within operational limits.

Abstract: A low stress seal seals boundaries between rotor sections of a turbofan engine. The low stress seal includes rounded feet on the ends of legs, which rounded feet cooperate with rounded interior corners within a seal groove. The elimination of sharp interior corners reduces stress and prevents the fatigue failures.

Abstract: A face seal assembly with internal weep drain is disclosed for use in a turbo-machine, such as a gas turbine engine, for deterring passage of fluids, such as oil and the like, across an interface dividing the turbo-machine into two distinct regions, the interface being defined between one surface of a seal element and a second surface mounted on a rotating shaft. The face seal assembly includes a housing having a first fixed member including a drain opening, a second member supported for axial motion relative to the first member, and a biasing element positioned between the first and second members for urging the second member toward the interface. The second member supports the seal element and defines with the first member a channel through which the fluids that migrate past the interface are directed into the housing and out through the drain opening.