A sealing apparatus for an axial flow turbomachine is disclosed. An example axial flow turbomachine includes band segments bordering a flow path, a first spline seal disposed at a first angle within a first slot of the band segments, a second spline seal disposed at second angle within a second slot of the band segments, a Z-seal disposed across a gap between the first slot and the second, the Z-seal positioned at least partially within the first slot and the second slot. The Z-seal includes a first segment disposed at the first angle at least partially within the first slot, the first segment to contact the first spline seal, a second segment disposed at the second angle at least partially within the second slot, a portion of the second segment in connection with a portion of the first segment, the second segment to contact the second spline seal.

A turbine engine that includes an engine core, an inner cowl, an outer cowl and an accessory gearbox. The engine core includes at least a compressor section, a combustion section, and a turbine section in axial flow arrangement. The accessory gearbox is operably coupled to the engine core and includes a first portion and a second portion.

A turbine engine that includes an engine core, an inner cowl, an outer cowl and an accessory gearbox. The engine core includes at least a compressor section, a combustion section, and a turbine section in axial flow arrangement. The accessory gearbox is operably coupled to the engine core and includes a first portion and a second portion.

A gas turbine engine including: a high pressure turbine, a low pressure turbine, a high pressure compressor coupled to the high pressure turbine by a high pressure shaft, a propulsor and a low pressure compressor coupled to the low pressure turbine via a low pressure shaft and a reduction gearbox; wherein the high pressure compressor defines an average stage pressure ratio at cruise conditions of between 1.25 and 1.35 and consists of 10 or 11 stages; and the high pressure compressor and low pressure compressor together define a core overall pressure ratio at cruise conditions of between 40:1 and 60:1.

A gas turbine engine including: a high pressure turbine, a low pressure turbine, a high pressure compressor coupled to the high pressure turbine by a high pressure shaft, a propulsor and a low pressure compressor coupled to the low pressure turbine via a low pressure shaft and a reduction gearbox; wherein the high pressure compressor defines an average stage pressure ratio at cruise conditions of between 1.25 and 1.35 and consists of 10 or 11 stages; and the high pressure compressor and low pressure compressor together define a core overall pressure ratio at cruise conditions of between 40:1 and 60:1.

A method of controlling a gas turbine engine including receiving an instantaneous thrust demand for current operation of the engine, determining the inlet flow rate and/or the pressure ratio within the compressor of the engine and determining whether the inlet flow rate and/or the pressure ratio match the working line for the compressor. The angle of one or more vane of the compressor is adjusted according to a closed control loop if the inlet flow rate and/or pressure ratio lie outside said desired range in order to adjust the inlet inflow rate and/or pressure ratio to meet the working line. The fuel flow to the engine combustor is adjusted concurrently in order to meet the thrust demand.

A gas turbine engine which includes an outer casing; a central longitudinal hollow shaft with a forward air inlet; a three stage rotating superconducting electric bypass fan with front and rear fan blades and a diffuser blade interposed between said front and rear fan blades wherein the diffuser blade rotates in an opposite direction to the front and rear fan blades; a multiple stage superconducting axial compressor positioned aft of the three stage rotating superconducting electric bypass fan; a multiple stage superconducting electric turbine core positioned aft of the multiple stage variable speed superconducting axial compressor, whereby the electric power from the multiple stage superconducting electric turbine core powers the three stage superconducting electric bypass fan and the multiple stage superconducting axial compressor.

A gas turbine engine which includes an outer casing; a central longitudinal hollow shaft with a forward air inlet; a three stage rotating superconducting electric bypass fan with front and rear fan blades and a diffuser blade interposed between said front and rear fan blades wherein the diffuser blade rotates in an opposite direction to the front and rear fan blades; a multiple stage superconducting axial compressor positioned aft of the three stage rotating superconducting electric bypass fan; a multiple stage superconducting electric turbine core positioned aft of the multiple stage variable speed superconducting axial compressor, whereby the electric power from the multiple stage superconducting electric turbine core powers the three stage superconducting electric bypass fan and the multiple stage superconducting axial compressor.

Methods and systems of starting a gas turbine engine are provided. During startup, a fuel pressure associated with a primary fuel supply of the gas turbine engine is monitored. A low-pressure event for the primary fuel supply is detected when the fuel pressure falls below a predetermined threshold. Responsive to detecting the low pressure event, an electric backup boost pump is activated by an engine controller to provide fuel to the gas turbine engine.

Methods and systems of starting a gas turbine engine are provided. During startup, a fuel pressure associated with a primary fuel supply of the gas turbine engine is monitored. A low-pressure event for the primary fuel supply is detected when the fuel pressure falls below a predetermined threshold. Responsive to detecting the low pressure event, an electric backup boost pump is activated by an engine controller to provide fuel to the gas turbine engine.