An engine system comprises a first fuel store, a second fuel store, an engine arranged to produce mechanical power by combustion or oxidation of a fuel in an engine, a fuel distribution system arranged to deliver fuel from the first and second fuel stores to the engine, the first fuel delivered at a first mass flow rate, the second fuel delivered at a second mass flow rate, the first and second mass flow rates contributing to a total mass flow rate of fuel to the engine; and a control system arranged to control the relative fractions of the total mass flow rate of fuel to the engine represented by the first mass flow rate and the second mass flow rate, based on an engine temperature.

A fuel injector system includes an outer support and an inner support, with a feed arm extending radially between the inner support and the outer support. A plurality of outlet openings extend in an axial direction from the feed arm for feeding respective injection nozzles. The outer support and feed arm define a plurality of fuel passages therethrough to convey fluid from an external source through the outer support and feed arm to the outlet openings. A heat shield extends around the feed arm from the outer support to the inner support. The heat shield is spaced apart from the feed arm with an insulative gap therebetween.

A method for determining mass differential in a hot gas path component of a gas turbine includes monitoring operational conditions of the gas turbine; determining whether changes in a gas turbine wheelspace temperature has occurred; determining whether a wheelspace temperature has changed by comparing the wheelspace temperature to at least one of a compressor inlet temperature and a compressor discharge temperature indicates a change in temperature; in response to determining the wheelspace temperature indicates a change in temperature has occurred; determining whether at least one of the following exists: a gas turbine exhaust temperature indicates a simultaneous change with the temperature change between wheelspace temperature compared to the at least one of the compressor inlet temperature and the compressor discharge temperature, and a gas turbine vibrational change. In response to at least one of the simultaneous change and the vibrational change existing, indicating a mass deviation in the hot gas path component of the gas turbine.

A method of detecting damage to a gas turbine engine, the method including observing a thermal response of the engine during a thermal transition occurring when the engine transitions between an elevated temperature and a lesser temperature; determining potential damage to the gas turbine engine based on the observed thermal response of the gas turbine engine; and generating an action in response to the determined potential damage to the gas turbine engine.

The present invention relates to a fuel metering unit for an aircraft engine, comprising: —a metering member configured to receive a position control signal and to meter the feed of fuel to the engine depending on said position control; —a cutting member configured to cut the feed of fuel to the engine; and characterized in that the fuel metering unit also has a computer for protecting and cutting the engine, said protecting and cutting computer being configured to—detect an overspeeding state of the engine speed and—in response to the detection of an overspeeding state, to transmit a cutting control signal to a cutting control member contained in the cutting member.

A method for monitoring the integrity of a set of air bleed lines from propulsion engines of an aircraft by: at the start of a use of the aircraft, sending air from an auxiliary power unit into the various lines; over a predetermined period of time, acquiring temperature measurements from temperature sensors associated with the lines; for each line, determining a gradient for rate of change in temperature with respect to time during this period of time; determining a discrepancy between the gradient for rate of change in temperature with respect to time corresponding to a line and a gradient for rate of change in temperature with respect to time corresponding to at least one other line; determining a condition indicator for the condition of the line as a function of the discrepancy determined for said line.

A method is provided of controlling a cooled cooling air system for an aeronautical gas turbine engine. The method includes: receiving data indicative of an ambient condition of the aeronautical gas turbine engine, data indicative of a deterioration parameter of the aeronautical gas turbine engine, data indicative of an operating condition of the aeronautical gas turbine engine, or a combination thereof; and modifying a cooling capacity of the cooled cooling air system in response to the received data indicative of the ambient condition of the aeronautical gas turbine engine, data indicative of the deterioration parameter of the aeronautical gas turbine engine, data indicative of an operating condition of the aeronautical gas turbine engine, or the combination thereof.

An engine control system may be configured to perform a method of controlling thermal bias in a turbomachine. An exemplary method may include determining a thermal bias-value for the turbomachine, and performing a cooling treatment based at least in part on the thermal bias-value. The thermal bias-value may include a difference between an upward temperature-value corresponding to a first one or more temperature measurements of an upward portion of the turbomachine and a downward temperature-value corresponding to a second one or more temperature measurements of a downward portion of the turbomachine. The cooling treatment may include at least one of: circulating air through at least a portion of the turbomachine, and rotating a shaft of the turbomachine with a motoring system.

A system for cooling a compartment for equipment in a nacelle having a member for drawing a cooling flow and a device for admitting the cooling flow into the compartment, having: a regulating member movably mounted with the ability to move in a first direction of movement limiting the admission when the internal pressure of the compartment is below the external pressure, and in a second direction of movement increasing the admission when the internal pressure is above the external pressure; a return member configured to keep the regulating member in a neutral open position and to damp the movement of the regulating member during modifications in the ratio of the pressures; a pressing member activated by a heat-sensitive element and configured to move the regulating number into a closed position so as to isolate the compartment in the event of fire.

Systems and methods for operating an engine are described herein. The engine is operated at low power by supplying fuel to a combustor through a first set of fuel nozzles of at least one first manifold and without supplying fuel to the combustor through a second set of fuel nozzles of at least one second manifold. An amount of fuel to at least in part fill the at least one second manifold to impede fuel coking of the second set of fuel nozzles is determined. The amount of fuel is periodically supplied to the at least one second manifold.