Abstract: The present disclosure relates generally to a method for determining a failure of a flow divider within a fuel system, the method being performed by a controller and comprising the steps of: delivering a fuel command, calculating an expected fill time, wherein the expected fill time is indicative of the time required to fill a known fuel manifold volume, determining whether the actual fill time is greater than or equal to an expected fill time; and determining whether an actual fuel pressure value is less than or equal to an expect fuel pressure value based at least in part on at least one environmental signal.

Abstract: The present disclosure relates generally to system and method for detecting fuel shutoff valve failures in a system including multiple fuel shutoff valves connected in series. By commanding different fuel shutoff valves to close and detecting changes in the system operating conditions, the system and method may determine if any of the fuel shutoff valves are not working properly.

Abstract: The present disclosure relates generally to system and method for detecting fuel shutoff valve failures in a system including multiple fuel shutoff valves connected in series. By commanding different fuel shutoff valves to close and detecting changes in the system operating conditions, the system and method may determine if any of the fuel shutoff valves are not working properly.

Abstract: The present disclosure relates generally to a method for determining a failure of a flow divider within a fuel system, the method being performed by a controller and comprising the steps of: delivering a fuel command, calculating an expected fill time, wherein the expected fill time is indicative of the time required to fill a known fuel manifold volume, determining whether the actual fill time is greater than or equal to an expected fill time; and determining whether an actual fuel pressure value is less than or equal to an expect fuel pressure value based at least in part on at least one environmental signal.

Abstract: A liquid replenishment system includes a reservoir, a first temperature sensor positioned in the reservoir at a full level, a second temperature sensor positioned in the reservoir at an add level, and a controller. The controller is connected to both the first and second sensors. The controller receives temperature signals from the first and second temperature sensors at first and second times. The controller sends an add liquid signal if temperature sensed by the first temperature sensor is substantially different at the first and second times and if temperature sensed by the second temperature sensor is substantially different at the first and second times. The controller sends a full signal if temperature sensed by the first temperature sensor is substantially the same at the first and second times and if temperature sensed by the second temperature sensor is substantially the same at the first and second times.

Abstract: A liquid replenishment system includes a reservoir, a first temperature sensor positioned in the reservoir at a full level, a second temperature sensor positioned in the reservoir at an add level, and a controller. The controller is connected to both the first and second sensors. The controller receives temperature signals from the first and second temperature sensors at first and second times. The controller sends an add liquid signal if temperature sensed by the first temperature sensor is substantially different at the first and second times and if temperature sensed by the second temperature sensor is substantially different at the first and second times. The controller sends a full signal if temperature sensed by the first temperature sensor is substantially the same at the first and second times and if temperature sensed by the second temperature sensor is substantially the same at the first and second times.

Abstract: A method of indicating low oil level of lubrication oil for a gas turbine engine automatically eliminates false low oil readings due to temperature-induced lubrication oil shrinkage and operation-induced changes in lubrication oil level.

Abstract: A method of indicating low oil level of lubrication oil for a gas turbine engine automatically eliminates false low oil readings due to temperature-induced lubrication oil shrinkage and operation-induced changes in lubrication oil level.

Abstract: A method of determining lubrication oil consumption in a gas turbine engine that has an engine operating cycle interval comprising a starting phase, a running phase and a shutdown phase, comprises the steps of: measuring lubrication oil level upon initialization of the starting phase of each engine operating cycle interval; comparing the starting phase measured lubrication oil level during the starting phase with a starting phase baseline lubrication measurement; recording the starting phase lubrication oil level measurement; determining average engine lubrication oil consumption rate during the complete engine operating cycle interval by dividing the difference between the starting phase lubrication oil measurement and the baseline lubrication oil measurement; and repeating these steps for each subsequent engine operating cycle interval; wherein the starting phase baseline lubrication oil level measurement is initially a predetermined lubrication oil level and then the previous starting phase lubrication oil

Abstract: An event-driven starter controller regulates the speed of a gas turbine engine based on detected events. The event-driven starter controller is used to supply motive force to the gas turbine engine prior such that the gas turbine engine is able to ignite (i.e., achieve light-off). In particular, in response to engine speed reaching a defined threshold, the event-driven starter controller causes the speed of the starter motor to ramp or increase through a defined range of speeds suitable for engine light-off (i.e, light-off window). Upon reaching an upper threshold of the light-off window, the event-driven starter controller causes the speed of the starter motor to decrease through the range of speeds suitable for engine light-off. If at any time during the light-off window the event-driven starter controller detects a successful light-off condition, the event-driven starter controller causes the speed of the gas turbine engine to increase toward a second threshold.

Abstract: An Auxiliary Power System includes an APU controller and an aircraft load controller which include an APU load capacity algorithm which provides an uncomplicated and robust method of APU load control. The APU load capacity algorithm defines three load zones: a continuous APU load capacity zone (zone A); a time controlled zone (zone B); and a fault zone (zone C). Each zone is related to altitude to the service ceiling of the APU to provides consistent APU load capacity that addresses APU performance variation and deterioration effects to an end of the APU useful life.

Abstract: An active thrust management system varies pressure responsive to changes in rotor assembly thrust to maintain a desired position. The system includes a bearing supporting rotation of a rotor assembly within a pressurizing chamber. The rotor assembly is supported on a cushion of air generated between the bearing and the rotor assembly. Pressure within a cavity adjacent the rotor assembly opposes a thrust force to maintain a desired position of the rotor assembly. Modulating airflow into the pressurizing chamber adjacent the rotor assembly compensates for changes in the thrust generated by the rotor assembly to maintain the desired rotor assembly position.

Abstract: A dual channel ignition circuit (Channel A and a Channel B). In a start sequence in which a successful ignition event occurs, an exciter controller first energizes only a primary ignition channel (Channel A). Once the exciter controller recognizes a success light-off, the alternate channel (Channel B) will also then be excited as the gas turbine engine is accelerated to a self-sustaining speed. The exciter controller will then switch the primary alternative designation of the channels for the next start attempt. In a start sequence in which an unsuccessful ignition event occurs, the exciter controller sets a fail-to-start on the primary ignition channel on a failure to start A/B counter such that a failed ignition channel is diagnosed without dedicated electronic diagnostic circuits while still attempting to excite both circuits to enhance the dependability of a successful engine light-off.

Abstract: A method of determining lubrication oil consumption in a gas turbine engine that has an engine operating cycle interval comprising a starting phase, a running phase and a shutdown phase, comprises the steps of: measuring lubrication oil level upon initialisation of the starting phase of each engine operating cycle interval; comparing the starting phase measured lubrication oil level during the starting phase with a starting phase baseline lubrication measurement; recording the starting phase lubrication oil level measurement; determining average engine lubrication oil consumption rate during the complete engine operating cycle interval by dividing the difference between the starting phase lubrication oil measurement and the baseline lubrication oil measurement; and repeating these steps for each subsequent engine operating cycle interval; wherein the starting phase baseline lubrication oil level measurement is initially a predetermined lubrication oil level and then the previous starting phase lubrication oil

Abstract: An event-driven starter controller regulates the speed of a gas turbine engine based on detected events. The event-driven starter controller is used to supply motive force to the gas turbine engine, prior such that the gas turbine engine is able to ignite (i.e., achieve light-off). In particular, in response to engine speed reaching a defined threshold, the event-driven starter controller causes the speed of the starter motor to ramp or increase through a defined range of speeds suitable for engine light-off (i.e, light-off window). Upon reaching an upper threshold of the light-off window, the event-driven starter controller causes the speed of the starter motor to decrease through the range of speeds suitable for engine light-off. If at any time during the light-off window the event-driven starter controller detects a successful light-off condition, the event-driven starter controller causes the speed of the gas turbine engine to increase toward a second threshold.

Abstract: An exciter circuit for a gas turbine engine delivers a first single high-energy spark followed by subsequent sparks of relatively lower energy to ensures start reliability by specifically clearing ice build-up at the ignition plugs.

Abstract: An APU system provides an APU which drives a permanent magnet generator, an APU controller and a fuel controller. The APU controller controls the APU speed through communication with the fuel controller to maintain the generator voltage output within specified limits in response to an engine speed set point signal, a voltage set point signal and a voltage output signal.