A method for monitoring a starting sequence of a turbomachine including a compressor provided with a rotor, a starter capable of rotating the rotor and a combustion chamber, the method including determining a bracketing of a time zone during which the ignition instant takes place, the bracketing being defined by, on the one hand, a lower limit corresponding to an event necessarily taking place before the ignition instant and an upper limit corresponding to an event necessarily taking place after the ignition instant; and determining between the lower limit and the upper limit, a break point in the variation with time of the measurement signal, this break point corresponding to an ignition instant of the air-fuel mixture in the combustion chamber.

In accordance with at least one aspect of this disclosure, there is provided a fuel system for a gas turbine engine of an aircraft, including a main inlet feed conduit fluidly connected to a primary manifold feed conduit and a secondary manifold feed conduit. A primary manifold fluidly connects the primary manifold feed conduit to a plurality of primary fuel injectors, and a secondary manifold fluidly connects the secondary manifold feed conduit to a plurality of secondary fuel injectors.

An air starter for starting a turbine engine that includes a housing, a turbine member, a drive shaft, and at least one bearing assembly. The housing can define an interior where the turbine couples to the drive shaft that is rotatably supported by the least one bearing assembly. A lubricant passageway can provide lubrication to the at least one bearing assembly.

Methods and systems for starting an aircraft gas turbine engine are described. The method comprises, in a first phase of a startup upon receipt of a start request, modifying a first set of engine control parameters to cause light-up; in a second phase of the startup, modifying a second set of engine control parameters to set conditions for light-around; and in a third phase of the startup, modifying a third set of engine control parameters to propagate a flame around a combustor of the gas turbine engine.

A method of controlling a gas turbine engine. The gas turbine engine has a compressor, a combustor, and a motor configured to drive the compressor. The method has in a first idle mode, controlling combustor fuel flow to maintain compressor rotational speed at or above a predetermined value; and in a second idle mode, controlling the combustor and the motor to drive the compressor to maintain the compressor rotational speed at or above a second predetermined value, lower than the first predetermined value.

A fuel injector includes a fuel nozzle configured to issue a spray of fuel from a fuel outlet in a downstream direction along an injection axis. The fuel nozzle defines a main flow passage therethrough. An injection fuel line is in fluid communication with the fuel nozzle to supply fuel to the fuel nozzle. A torch ignitor has a flame outlet opening into the main flow passage of the fuel nozzle for issuing flame into the main flow passage.

According to an aspect, a bowed rotor sensor system for a gas turbine engine is provided. The bowed rotor sensor system includes a bowed rotor sensor operable to transmit a sensing field in an observation region and receive a signal indicative of a gap between an air seal and a blade tip within the gas turbine engine. The bowed rotor sensor system also includes a controller operable to monitor a plurality of gap data from the bowed rotor sensor indicative of the gap between the air seal and the blade tip of a plurality of blades passing through the observation region and determine a bowed rotor status of the gas turbine engine based on the gap data.

According to an aspect, a system for a gas turbine engine includes a reduction gear train operable to drive rotation of a starter gear train that interfaces to an accessory gearbox of the gas turbine engine. The reduction gear train includes a starter interface gear that engages the starter gear train and a core-turning clutch operably connected to the starter interface gear. The reduction gear train also includes a geared rotary actuator including a primary planetary gear system, where the geared rotary actuator is operably connected to the core-turning clutch. The reduction gear train further includes a secondary planetary gear system operably connected to the primary planetary gear system and a core-turning input. The system also includes a mounting pad with an interface to couple a core-turning motor to the core-turning input of the reduction gear train.

A motoring system for a gas turbine engine having: a reduction gear train having an input and output; a motor operably connected to the input; a clutch operably connected to the output, the clutch in operation engages and disengages the reduction gear train; and a pinned mechanical fuse operably connecting the output to the clutch, the pinned mechanical fuse having at least one shear pin. The pinned mechanical fuse having: an outer sleeve having a first section, second section, inner chamber, outer wall, and at least one through hole connecting the inner chamber to the outer wall within the first section; and an inner sleeve having a first portion, second portion, outer surface, and at least one blind hole located in the outer surface within the second portion. The second portion being located within the inner chamber and operably connected to the outer sleeve through at least one shear pin.

According to an aspect, a system for a gas turbine engine includes a reduction gear train operable to drive rotation of a starter gear train that interfaces to an accessory gearbox of the gas turbine engine. The reduction gear train includes a starter interface gear that engages the starter gear train, a core-turning clutch operably connected to the starter interface gear, and a plurality of stacked planetary gear systems operably connected to the core-turning clutch and a core-turning input. The system also includes a mounting pad including an interface to couple a core-turning motor to the core-turning input of the reduction gear train.