Abstract: A gas turbine engine includes a casing including a plurality of interconnected casing segments defining an outer surface of the casing. One of the casing segments is a gearbox segment enclosing a gearbox and having a gearbox flange extending radially outwardly from the outer surface of the casing. The engine includes a bearing housing enclosing at least one bearing and having an annular body with an inner segment disposed within the casing. The annular body having an extension segment extending radially outwardly from the inner segment to a bearing housing flange disposed radially-outwardly of the outer surface of the casing. The bearing housing flange is engageable with the gearbox flange to removably mount the gearbox segment to the bearing housing.

Abstract: A method of manufacturing a compressor stator having: a first stator blade with a first leading edge and a first trailing edge; a second stator blade disposed a circumferential distance from the first stator blade, the second stator blade having a second leading edge disposed an axial distance from the first leading edge and a second trailing edge disposed an axial distance from the first trailing edge; the method comprising: using additive manufacturing to deposit and fuse together progressive layers of metal material commencing at a substrate to form the first stator blade, the second stator blade, at least one intermediate support structure disposed between the first stator blade and the second stator blade, and at least one primary support structure disposed between the substrate and at least one of: the first stator blade; and the second stator blade; and removing the primary support structure and the intermediate support structure.

Abstract: A gas turbine engine includes a casing including a plurality of interconnected casing segments defining an outer surface of the casing. One of the casing segments is a gearbox segment enclosing a gearbox and having a gearbox flange extending radially outwardly from the outer surface of the casing. The engine includes a bearing housing enclosing at least one bearing and having an annular body with an inner segment disposed within the casing. The annular body having an extension segment extending radially outwardly from the inner segment to a bearing housing flange disposed radially-outwardly of the outer surface of the casing. The bearing housing flange is engageable with the gearbox flange to removably mount the gearbox segment to the bearing housing.

Abstract: A method of manufacturing a compressor stator having: a first stator blade with a first leading edge and a first trailing edge; a second stator blade disposed a circumferential distance from the first stator blade, the second stator blade having a second leading edge disposed an axial distance from the first leading edge and a second trailing edge disposed an axial distance from the first trailing edge; the method comprising: using additive manufacturing to deposit and fuse together progressive layers of metal material commencing at a substrate to form the first stator blade, the second stator blade, at least one intermediate support structure disposed between the first stator blade and the second stator blade, and at least one primary support structure disposed between the substrate and at least one of: the first stator blade; and the second stator blade; and removing the primary support structure and the intermediate support structure.

Abstract: A sleeve is provided for supplying lubricant to an inter-shaft bearing mounted between co-axially mounted inner and outer shafts of a gas turbine engine. The sleeve has a sleeve annular outer surface and a sleeve annular inner surface. At least one lubricant supply connecting member extends from the sleeve outer surface for connection to a lubricant supply. At least one sleeve channel fluidly links the sleeve annular inner surface to the lubricant supply connecting member.

Abstract: A multi-spool gas turbine engine comprises a low pressure (LP) spool and a high pressure (HP) spool. The LP spool has an LP shaft for transferring a torque from an LP turbine to an LP compressor. The HP spool has an HP shaft for transferring a torque from an HP turbine to an HP compressor. The LP shaft is coaxially mounted inside the HP shaft. An inter-shaft bearing is mounted radially between the LP shaft and the HP shaft. The inter-shaft bearing is disposed axially between the HP compressor and the LP compressor.

Abstract: A sleeve is provided for supplying lubricant to an inter-shaft bearing mounted between co-axially mounted inner and outer shafts of a gas turbine engine. The sleeve has a sleeve annular outer surface and a sleeve annular inner surface. At least one lubricant supply connecting member extends from the sleeve outer surface for connection to a lubricant supply. At least one sleeve channel fluidly links the sleeve annular inner surface to the lubricant supply connecting member.

Abstract: Systems and methods for changing a speed ratio between a compressor boost stage (12) and at least one power turbine (16) of a gas turbine engine (10) are described. Such a system may comprise a coupling device (20) configured to selectively transmit energy from the at least one power turbine (16) to the boost stage (12) according to at least a first speed ratio and a second speed ratio. The system may also comprise an auxiliary power device (22, 26) configured to cause a rotational speed of the boost stage (12) to change from a first speed corresponding substantially to the first speed ratio to a second speed corresponding substantially to the second speed ratio when the boost stage (12) is decoupled from the at least one power turbine (16).

Abstract: Systems and methods for changing a speed ratio between a compressor boost stage (12) and at least one power turbine (16) of a gas turbine engine (10) are described. Such a system may comprise a coupling device (20) configured to selectively transmit energy from the at least one power turbine (16) to the boost stage (12) according to at least a first speed ratio and a second speed ratio. The system may also comprise an auxiliary power device (22, 26) configured to cause a rotational speed of the boost stage (12) to change from a first speed corresponding substantially to the first speed ratio to a second speed corresponding substantially to the second speed ratio when the boost stage (12) is decoupled from the at least one power turbine (16).

Abstract: Systems and methods for driving an oil cooling fan (36) of a gas turbine engine (10) during different modes of operation of the gas turbine engine (10) are described. A system may include a coupling device (40) configured to: transmit motive power from a power turbine shaft (22) of the gas turbine engine (10) to the oil cooling fan (36) during a first mode of operation where the power turbine shaft (22) is turning, and to decouple the oil cooling fan (36) from the power turbine shaft (22) during a second mode of operation where the power turbine shaft (22) is prevented from turning. An alternate source (42) of motive power may be configured to drive the oil cooling fan (36) during the second mode of operation.

Abstract: A method and apparatus for heating fuel in an aircraft gas turbine engine, for example to provide fuel anti-icing to the fuel, comprises directing a fuel flow through a heat exchanger associated with a generator power conditioning unit as a sole means for providing anti-icing heating to fuel supplied for engine combustion. The method and apparatus permits the heat exchanger to heat the fuel sufficiently so that other dedicated heating means may be unnecessary.

Abstract: Methods and apparatus are provided for processing messages for access to information stored in an open directory. A Lightweight Directory Access Protocol (LDAP) LDAP Validation Proxy (LVP) is used to intercept LDAP request messages intended for the directory, validates the LDAP requests according to a schema description and optionally provides side-effects. The schema validation and LDAP message processing is modularized according to object classes representing the data stored in the directory and according to services provided. The schema is enforced by validating LDAP messages. This modularization provides a controlled message processing granularity and enables multi-threaded concurrent processing of multiple LDAP messages. The LVP has the capability of generating LDAP requests in processing LDAP messages. The LVP also intercepts and processes LDAP responses issued by a directory and intended for clients.