Abstract: An aircraft is provided. The aircraft includes a pressurized volume and an air conditioning system. The air conditioning system operates in a first mode when the aircraft is performing high altitude operations and a second mode when the aircraft is performing low altitude operations. The first mode includes when a first medium, a second medium, and a third medium are mixed by the air conditioning system to produce a chamber ready medium. The second mode comprises when only the first medium and the second medium are mixed by the air conditioning system to produce the chamber ready medium. The air conditioning system provides the chamber ready medium to the pressurized volume.

Abstract: A mechanical decoupler (15) at the inlet to a turbomachine is positioned on the outside of an intake casing, where radiating arms (27) meet an external casing (13) so as to partially unload a low-pressure shaft when a significant out-of-balance appears. Because it is positioned a long way from the bearing, the decoupler (15) can be designed with a greater degree of freedom at a location where there is more space available and where layout constraints are less of an issue. More specifically, it is housed in a cavity (30) of the external casing (13) which opens onto the flow path (5).

Abstract: The present invention relates to a pneumatically, high pressure gas powered emergency release coupling control and monitoring system (S) comprising a powered emergency released coupling (1) arranged in a fluid-supply line (32) for conveying hazardous fluids, said powered emergency released coupling (1) comprising a couple of coupling members (10, 11) provided with mating faces (10A, 11A) for sealing engagement of the coupling members (10, 11) and formation of a pressurizable chamber (12) between said coupling members (10, 11), said system (S) comprising an actuation line (7) connected at its one end to the pressurizable chamber (12) and at its other end to a source (C) of high pressure gaseous media (GH), preferably high pressure nitrogen gas, an first actuating device (4A, 4B) arranged in the actuation line (7), wherein said system (S) provides a gaseous media at a pilot pressure level to said pressurizable chamber (12) and to said actuation line (7) in a position downstream the first actuation device (4A, 4

Abstract: A turbine is operably connected to drive a compressor, and to drive a fan through a gear drive. A number of intermediate gears connecting an output shaft of the turbine to a fan drive shaft for the fan. An oil channel collects oil thrown outwardly of the gear drive. A bearing support mounts bearings supporting the fan drive shaft. The oil channel and the bearing support each include mating faces that are bolted together by a plurality of bolts. The bolts extend through oil channel holes in the mating face of the oil channel. The oil channel holes have one dimension which closely receives the bolts and another dimension which is larger than an outer diameter of the extending portion of the bolts, such that the bolts may adjust radially within the oil channel holes.

Abstract: The present invention relates to a pneumatically, high pressure gas powered emergency release coupling control and monitoring system (S) comprising a powered emergency released coupling (1) arranged in a fluid-supply line (32) for conveying hazardous fluids, said powered emergency released coupling (1) comprising a couple of coupling members (10, 11) provided with mating faces (10A, 11A) for sealing engagement of the coupling members (10, 11) and formation of a pressurizable chamber (12) between said coupling members (10, 11), said system (S) comprising an actuation line (7) connected at its one end to the pressurizable chamber (12) and at its other end to a source (C) of high pressure gaseous media (GH), preferably high pressure nitrogen gas, an first actuating device (4A, 4B) arranged in the actuation line (7), wherein said system (S) provides a gaseous media at a pilot pressure level to said pressurizable chamber (12) and to said actuation line (7) in a position downstream the first actuation device (4A, 4

Abstract: A gas turbine guide vane segment has a first guide vane part with an aerofoil and a first platform section and a second guide vane part with a second platform section. The first guide vane part and the second guide vane part are separately manufactured parts joined together such that the second platform section defines a leading edge of the gas turbine guide vane segment and such that the first platform section and the second platform section form an aligned common platform surface of the gas turbine guide vane segment. The first platform section includes slots in the first platform section for guiding cooling fluid along a surface of the first platform section for film cooling of the surface, the slots being provided at an upstream bend of the first platform section and the slots are provided on a side of the first platform section facing the working fluid.

Abstract: A method of preventing standing waves in an installed gas turbine having a fan, having a fan speed, and a compressor, having a compressor speed, includes correcting the fan and compressor speeds for temperature and monitoring the corrected speeds to prevent them from converging, or becoming the same value. In addition, a computer implemented monitoring and adjusting program may monitor a position of an aircraft on an Acoustic Critical Turbo System Frequency (ACTSF) plot and make adjustments to avoid intercepting a surge line by changing the speed of the plane, one or both of the fan or compressor speeds or by changing altitude. An aircraft may form a standing wave when crossing or operating on a surge line of an ACTSF plot and this condition should be avoided which may require high data rate monitoring and control logic.

Abstract: Air Turbine Starters (ATSs) having oil feed shutoff valves are provided, as are gas turbine engines including ATSs. In one embodiment, the ATS includes an ATS housing assembly containing a sump chamber, an oil inlet, and a valve cavity. A rejected oil return passage is further formed in the ATS housing assembly and fluidly coupled to the valve cavity. An oil feed shutoff valve is positioned in the valve cavity and contains a valve element movable between open and closed positions. In the open position, the valve element permits oil flow from the oil inlet, through the valve cavity, and into the sump chamber. In the closed position, valve element blocks oil flow from the oil inlet into the sump chamber, while redirecting the oil flow into rejected oil return passage to reduce the loss of engine oil through the ATS in the event of an ATS housing breach.

Abstract: A valve is provided. The valve includes a housing including an interior and a side wall at least partially delimiting the interior, a valve element within the interior of the housing and configured to be selectively operable between an open position and a closed position. The valve element includes an interior and a side wall at least partially delimiting the interior of the valve element. The valve also includes a series of pressure relief devices within the side walls of the housing and the valve element. The series of pressure relief devices include at least one check valve and are configured to provide flow communication from the interior of the housing to exterior of the housing upon actuation of the at least one check valve.

Abstract: Systems and methods for controlling the startup of a gas turbine are described. A gas discharge component may be configured to discharge gas from a compressor component associated with the gas turbine. A fuel control component may be configured to control a fuel flow provided to a combustor component associated with the gas turbine. A drive component may be configured to supply a rotational force to a shaft associated with the gas turbine. At least one control device may be configured to (i) direct the gas discharge component to discharge gas from the compressor component, (ii) direct the fuel control component to adjust the fuel flow, and (iii) direct the drive component to rotate the shaft.

Abstract: A system, which may be a propulsion system or a vehicle having a propulsion system, for example, an air-vehicle, a land vehicle or a marine vehicle, includes a gas turbine engine operative to drive a propulsor. The propulsor may be, for example, a fan/turbofan, a propeller, a turbine, or any rotor system for propelling an aircraft; a system for providing tractive effort for a land vehicle, such as one or more transmissions and wheel/track systems; and/or may be one or more marine propulsive devices, such as shrouded or unshrouded propellers, hydrojets and/or jet-pumps for surface vessels and/or submarines. The system also includes an auxiliary power unit. The auxiliary power unit is coupled to the gas turbine engine, and is operative to supply rotational power to the propulsor and to the impart motion to the vehicle using the propulsor, without starting the gas turbine engine.

Abstract: A variable heat/power ratio cogeneration system is provided that is capable of suppressing NOx emissions to a minimum while ensuring stability of combustion of a gas turbine combustor even when the ratio of gasification gas to normal fuel (e.g., natural gas or light fuel oil) to be used is changed or the composition of the gasification gas fuel is changed. The system includes a first steam system injecting extra steam upstream of the flame zone; a second steam system branched from the first system and injecting extra steam downstream of the flame zone; first and second steam flow rate control valves controlling steam injected by first and steam systems, respectively; and a controller that controls first and second control valves based on (1) flow rates of the gasification gas and normal fuel and (2) demanded steam.

Abstract: A system and method for startup control of a gas turbine is disclosed. The system and method includes defining a target startup time for the startup of the gas turbine and determining a remaining time to achieve the target startup time. The system and method includes monitoring at least one parameter associated with the startup and determining a first operating point for the parameter. The system and method adjusts the first operating point for the parameter to a second operating point based at least in part on the remaining time for the startup. The system and method controls an effector based on the second operating point for the parameter.

Abstract: A starter motor has a housing. The housing receives the starter motor and a plurality of locations to receive lubricant. The lubricant supply system shares a lubricant source with a main gas turbine engine to be started by the starter motor. The lubricant supply system has a shutoff valve. The shutoff valve is opened when starter motor is being driven to start a main gas turbine engine. The shutoff valve is generally closed once the main gas turbine engine is started.

Abstract: A system including a fuel-supply system including, an auxiliary-fuel-gas compressor configured to compress a fuel for use by a gas-turbine system, an expander configured to generate power by expanding an oxidant from the gas-turbine system, and a motor/generator configured to function in a motor mode and in a generator mode, wherein the motor/generator drives fuel compression with the auxiliary fuel-gas compressor in the motor mode, and the motor/generator generates power in the generator mode as the expander uses oxidant from the gas-turbine system to drive the motor/generator

Abstract: Method for conditioning a power supply for starting a jet engine having an electrical starting system with an auxiliary power unit in parallel with a DC power supply.

Abstract: A method is provided for connecting at least one further steam generator to a first steam generator in a power plant. The power plant includes at least two steam generators and a steam turbine, in which a fluid used to drive the steam turbine is conveyed in a fluid circuit having a plurality of steam systems. The steam systems are assigned individual steam generators and are able to be separated from one another by shut-off valves. The fluid of at least the first steam generator is connected to the steam turbine. The method involves opening the shut-off valve of at least one first steam system of the at least one further steam generator before the steam of the at least one further steam generator has reached approximately the same steam parameters as the steam of the first steam generator, so that steam can flow into the further steam generator.

Abstract: An assembly for driving accessories of a gas turbine is provided. The assembly includes: a gearbox having a front side face and a rear side face opposite the front face and having mounted therein a first gear train made up of three toothed wheels meshing with one another, and a second gear train made up of four toothed wheels meshing with one another; a power transmission shaft that is coupled in rotation with the first and second gear trains by a toothed wheel pair, and that emerges from the front side face of the gearbox; and nine distinct gas turbine accessories mounted against the side faces of the gearbox, and each including a respective drive shaft that is coupled in rotation with one of the toothed wheels of the two gear trains.

Abstract: The invention provides a device and a method for starting at least one turbine engine (1) fitted to a helicopter. A starter (6) is fed with electrical energy from an electricity network (8) including at least one battery (9) and/or an electrical energy generator member. Discharge members (10) suitable for providing the starter (6) with a short-term boost of electrical energy in the form of a high-power pulse are incorporated in the network (8). The current pulse is delivered at a determined instant T starting from when the starter (6) is itself started, and/or from a determined threshold S for the speed and/or the variation in the speed with which the compressor (2) of the turbine engine (1) is driven, and/or from detecting D the ignition stage of the turbine engine (1), and/or from a manual control.

Abstract: A bearing chamber venting system for an aircraft engine includes at least one bearing chamber air-sealed by sealing air via bearing chamber seals, a vent line connected to the bearing chamber, via which an oil/air mixture present in the bearing chamber is vented out, and an oil separator connected to the vent line. An oil return line is connected to the oil separator via which oil separated from the mixture is discharged. An air outlet line is connected to the oil separator, via which cleaned air is passed to the environment. An air ejector is arranged in the air outlet line to eject gas supplied to the air ejector into the air outlet line at a speed which is greater than the speed of the air flowing in the air outlet line and passed to the environment out of the oil separator.

Abstract: A valve skirt is connected to a shaft. The shaft extends in a rearward direction away from the skirt and has rack teeth at a location spaced away from the skirt. A tab is positioned between the skirt and the rack teeth, and has at least one flat surface. A rack support supports the rack for axial movement, and the rack support has a support ear that has a flat surface engaging the flat surface on the rack to prevent relative rotation of the rack when driven by a pinion gear. An air starter valve, a gas turbine engine and a method are also disclosed.

Abstract: A fire enclosure for an auxiliary power unit having a hot zone formed by a gas turbine comprises an annular fire enclosure body, an axial expansion joint and a radial expansion joint. The annular fire enclosure body is configured to encapsulate the hot zone. The fire enclosure includes a first end and a second end. The axial expansion joint is connected to the first end. The radial expansion joint is connected to the second end.

Abstract: This Mobile Driven Hydraulic Power Unit (HPU) provides a source of clean, pressurized hydraulic fluid for performing required aircraft maintenance. The unit sits on a heavy duty towable frame designed for off-road terrain. Electric start engine, fully instrumented operation panel for both the engine and hydraulic system. A gasoline engine or diesel engine may be used to power the HPU.

Abstract: A liquid fuel assist ignition system for providing a fuel/air mixture to a gas turbine in its start-up phase includes a high pressure tank, a vacuum pump connected to the high pressure tank, a liquid fuel inlet connected to the high pressure tank, an air inlet connected to the high pressure tank, and an outlet of the high pressure tank connected to a burner of the gas turbine.

Abstract: An engine system for starting a gas turbine engine includes a starter coupled to the gas turbine engine and configured to provide torque to the gas turbine engine; and a controller coupled to the starter and configured to evaluate an engine system parameter and to select from a plurality of start modes for starting the gas turbine engine based on the engine system parameter.

Abstract: A multi-engine system 10 for use on an aircraft 14 is disclosed. The system 10 may comprise a first aircraft engine 16A and a second aircraft engine 16B configured to drive at least one device 12 of the aircraft 14. A starter 20 may be coupled to one of the first and second aircraft engines 16A, 16B to assist starting of the one of the first and second aircraft engines 16A, 16B. An energy source 24 may be configured to deliver energy to the starter 20 at a rapid rate during rapid starting of the one of the first and the second aircraft engines 16A, 16B, the rapid rate being higher than a regular rate used during regular starting of the one of the first and the second aircraft engines 16A, 16B. The energy source 24 may comprise at least one supercapacitor.

Abstract: A control apparatus for angling guide vanes of a torque converter is provided and includes a modeling unit configured to receive current condition data, to determine a current input power supplied by a starting motor from the current condition data and to output a result of the determination as a control signal and a controller, which is coupled to the modeling unit and thereby receptive of the control signal. The controller is configured to execute a comparison of the current input power with a rating of the starting motor and to angle the guide vanes of the torque converter at an angle in accordance with a result of the comparison.

Abstract: An air starter for turbomachine, including a forward casing, an aft casing, an annular exhaust flow path opening up between an aft end of the forward casing and a forward end of the aft casing, and a cylindrical outlet mesh of the exhaust flow path is disclosed. The forward and aft ends of the outlet mesh include devices for axially retaining the forward casing and the aft casing respectively to the mesh. At least one of the devices for axially retaining one of the casings to the mesh enables a relative rotation of the mesh and this casing.

Abstract: An integrated oxy-combustion power generation process is provided. This process includes providing an air separation unit for producing at least an oxygen-enriched stream, providing a carbon dioxide recycle stream, which is combined with the oxygen-enriched stream thereby producing a synthetic air stream, providing a gas turbine comprising a gas inlet , a combustor, and a gas outlet, wherein the synthetic air stream is introduced into the gas inlet, providing a fuel stream to the combustor, thereby producing a power output, and a hot exhaust gas stream, which exits the gas outlet, introducing the exhaust gas stream, along with a boiler feed water stream, into a heat recovery steam generator, thereby producing a steam stream and a cooled exhaust gas stream, and separating the cooled exhaust gas stream into an enriched carbon dioxide product stream and the carbon dioxide recycle stream.

Abstract: A gas turbine starting architecture is used to start a gas turbine engine having at least a first spool. The architecture includes an electric power distribution bus, a motor, a compressor, a pneumatic distribution circuit, an air turbine starter, and a first tower shaft. The motor converts electric power provided by the electric power distribution bus to mechanical power. In turn, the mechanical power provided by the motor is converted to pneumatic power by the compressor for provision to a pneumatic distribution circuit. The air turbine starter converts pneumatic power from the pneumatic distribution circuit to mechanical power is provided via the first tower shaft to the at least one spool on the gas turbine engine.

Abstract: The system and method of the present invention provides stepping speed control of a gas turbine engine to reliably light-off a gas turbine engine. During starting, the speed of the gas turbine engine is incremented by stepped amounts through the light-off window from a minimum speed value to a maximum speed value, with the speed of the gas turbine dwelling at each stepped value for a period of time before incrementing the speed of the engine to the next stepped level. If the gas turbine engine is stepped through the entire light-off window without success, the controller decreases the speed of the gas turbine engine to the minimum value and begins the process again. The process continues until successful light-off is initiated or until the light-off window is traversed a certain number of times, after which the start process is aborted.

Abstract: A marine vessel control apparatus is arranged to start and stop engines that are respectively provided in multiple propulsion devices. The marine vessel control apparatus includes multiple individual start/stop switches arranged to correspond to the respective multiple propulsion devices and arranged to be operated by an operator to individually start and stop the engines in the respective multiple propulsion devices, an all-device start/stop switch arranged to be operated by the operator to collectively start and stop the engines in the multiple propulsion devices, an operating state acquiring unit arranged to acquire operating states of the engines in the respective multiple propulsion devices, and a control unit. The control unit includes multiple input ports corresponding to the respective multiple individual start/stop switches. Each of the input ports is connected with the corresponding individual start/stop switch. All of the input ports are connected commonly with the all-device start/stop switch.

Abstract: An example method of fuel delivery to a turbomachine includes reaching a light-off speed of a turbomachine and delivering fuel to a combustor of the turbomachine at a first rate. The method also increases the rate of the delivery. The combustor achieves light-off at a fuel flow rate on or in-between the first rate and a second rate that is greater than the first rate. An example turbomachine fuel delivery assembly includes a fuel delivery component and a controller configured to adjust the fuel pump to increase a rate of fuel delivery from a fuel supply to a combustor of a turbomachine.

Abstract: A consumption amount of high-calorific gas such as coke oven gas (COG) during operation of a gas turbine is reduced, halt of the gas turbine due to clogging of a pilot system, a malfunction of a compressor which compresses high-calorific gas is prevented, and reliability of the gas turbine is improved. When operation of the gas turbine (11) starts, with use of both a first fuel supply system (31) which supplies a high-calorific fuel for a first nozzle constituting a combustor (17), and a second fuel supply system (32) which supplies a low-calorific fuel for a second nozzle constituting the combustor (17), the high-calorific fuel and the low-calorific fuel are supplied to the combustor (17), and at a time when the gas turbine (11) reaches output power which enables continuous operation with only the low-calorific fuel, supply of the high-calorific fuel to the combustor (17) is shut off, and only the low-calorific fuel is supplied to the combustor (17).

Abstract: An aeronautical engine including a fuel pumping device including a high pressure fuel pump including an inlet connected to a low pressure fuel conduit and an outlet connected to a main circuit for feeding high pressure fuel, an electric device starting the engine, and a device cooling the electric starting device connected to the pumping device to ensure cooling by circulation of fuel. The cooling device is supplied with fuel by a pump that includes an inlet connected to the pumping device, upstream from the high pressure pump, and that is driven by an electric motor independently of the high pressure pump.

Abstract: In a cooling system used in cooling of a heater housing box, the present invention presents an apparatus for stabilizing power supply of heater housing box cooling apparatus capable of changing over a plurality of taps provided in the winding of a power transformer before the output voltage exceeds an allowable voltage range when turning on alternating-current power supply. For this purpose, first resistor 1 for elevating slowly the output voltage of the power transformer when turning on the alternating-current power supply is provided at the secondary side of the power transformer, direct-current voltage V1 rectified and smoothed from the output voltage is delayed by the charging time of a first capacitor, and an electronic controller for operating a tap changeover relay for automatically changing over the plurality of taps provided in the power transformer is started before the output voltage exceeds the allowable voltage range.

Abstract: A gas turbine plant associated with a solar thermal electric generation system has a heat receiver which receives heat from the sun, a gas turbine having a compressor and a turbine which operates with an operating fluid compressed by the compressor and heated by the heat receiver, a temperature sensor which detects heat from the sun, an auxiliary driving device which is driven based on the temperature of the heat detected by the temperature sensor, and which starts the gas turbine, and a generator which converts kinetic energy generated as a result of the rotation of the turbine into electric energy.

Abstract: A gas turbine engine incorporating a starter mounted on the gear box is disclosed. The gas turbine engine includes an AGB gear housing mechanically connected with an engine shaft for driving auxiliary machines and an air starter mounted on the housing, the starter and housing enclosures being in communication such that the lubricating oil of the starter should be distributed from the AGB housing. The oil enclosure of the starter is pressurized by a source of air, being independent from the AGB housing. Advantageously, the pressurization air is taken from a pressurization enclosure of an engine bearing.

Abstract: A start system for an engine package with a high spool includes a power source which generates air. A nozzle system in fluid communication with the power source, the nozzle system operable to direct air toward the high spool to spin-up the high spool.

Abstract: The invention provides a device and a method for starting at least one turbine engine (1) fitted to a helicopter. A starter (6) is fed with electrical energy from an electricity network (8) including at least one battery (9) and/or an electrical energy generator member. Discharge members (10) suitable for providing the starter (6) with a short-term boost of electrical energy in the form of a high-power pulse are incorporated in the network (8). The current pulse is delivered at a determined instant T starting from when the starter (6) is itself started, and/or from a determined threshold S for the speed and/or the variation in the speed with which the compressor (2) of the turbine engine (1) is driven, and/or from detecting D the ignition stage of the turbine engine (1), and/or from a manual control.

Abstract: The present application provides for a gas turbine engine system for turbine deceleration during shutdown procedures. The gas turbine engine system may include a rotor extending through a turbine, a generator engaged with the rotor, and a starting system in communication with the rotor. The starting system may reverse the operation of the generator so as to apply torque to the rotor during the shutdown procedures.

Abstract: Several improvements to an aircraft turbine engine and Auxiliary Power Unit (APU) are disclosed, as well as methods of using these improvements in routine and emergency aircraft operations. The improvements comprise the addition of cockpit-controllable clutches that can be used to independently disconnect the engine's integrated drive generator (IDG), engine driven pump (EDP), fuel pump, and oil pump from the engine gearbox. These engine components may then be connected to air turbines by the use of additional clutches and then powered by the turbines. Similar arrangements are provided for the APU components. Cranking pads, attached to various engine and APU components, are disclosed to provide a means for externally powering the components for testing purposes and to assist with engine and APU start.

Abstract: Air starter for turbomachine, comprising a forward casing (12), an aft casing (14), an annular exhaust flow path (32) opening up between an aft end of the forward casing and a forward end of the aft casing, and a cylindrical outlet mesh (44) of the exhaust flow path (32) the forward and aft ends of which comprise means (48, 52) of axially retaining the forward casing (12) and the aft casing (14) respectively to the mesh (44), wherein at least said means (52) of axially retaining one (14) of the casings to the mesh (44) enable a relative rotation of the mesh (44) and this casing (14).

Abstract: In an embodiment, a method includes determining a first heating value of a low BTU fuel, determining a target fuel quality level based on a state of a turbine system, controlling a second heating value of a high BTU fuel, and injecting the high BTU fuel into the low BTU fuel to achieve the target fuel quality level.

Abstract: A gas turbine engine is provided that includes a gearbox operable to selectively couple a relatively high pressure spool shaft to a relatively low pressure spool shaft. In one form the gearbox includes a cone clutch that engages a male member of the cone clutch to a female member of the cone clutch during an engine start of the gas turbine engine. A relatively high pressure of a working fluid can be used to bring the male member and the female member together. A spring can also be used to urge the male member and the female member apart when the working fluid is at a relatively low pressure.

Abstract: Starter arrangement for high power rotating equipment strings with multiple compressors driven by a single turbine or motor includes multiple variable fluid drive torque converters (CSTCs) to start the compressors in a pressurized start. The string can use a single CSTC for each compressor or a single CSTC for more than one compressor with at least two CSTCs for a given string. The starting procedure is sequential. After the turbine or motor is started and brought up to speed, successive CSTCs are operated from zero to lock-up speed sequentially to start each compressor or group of compressors in turn. In order to cool the working fluid of the CSTCs, a single heat exchanger is provided and the working fluid of each CSTC in turn is circulated through the heat exchanger as they are sequentially started.

Abstract: In order to start a turbine engine (10), high-pressure fluid is directed onto a turbine (34a) to cause rotation of the turbine and thereby start the turbine engine. In a disclosed embodiment, the high-pressure fluid is provided through a fluid outlet (120) in a vane (36a) positioned adjacent the turbine (34a). The high-pressure fluid is provided by an air source, which may be another turbine engine, especially where the turbine engine to be started is a tip turbine engine that is not the primary propulsion source.

Abstract: A turbine starter/generator machine for a turbine, said turbine comprising: at least one fan blade; at least one turbine enclosure; said starter/generator machine comprising: at least one rotor having rotor elements; at least one stator having stator elements; wherein said stator elements are mounted on said at least one air duct and said rotor elements are mounted on said at least one fan blade; whereby said stator elements magnetically interact with said rotor elements.

Abstract: An engine starting apparatus and method may allow for two methods of engine start where only one engine gearbox accessory pad exists off the aircraft engine. A gearbox lubricating apparatus may also be provided to lubricate the gearbox at altitude without added complexity. Two engine starting inputs (for example, one input for ground start and one input for in-flight engine start) are provided while avoiding complex gearbox designs. Clutches may also be used to prevent the starter gearbox from continuous operation (rotation) after the engine has started. Apparatus and methods are also provided for improving the air-fuel combustion of the hot-gas turbine start input (for in-flight engine start) to minimize the build-up of solid carbon (soot) in and around the combustor and turbine nozzle flow passages.

Abstract: A method of operating a power generation system is provided. The system includes a first gas turbine engine that uses at least one of a primary fuel and a secondary fuel, and at least one second gas turbine engine that operates using at least one of a primary and secondary fuel. The method includes supplying primary fuel to at least one of the first and second engines from a common fuel source coupled to the first and second engines, and selectively operating the first engine between a first operational position and a second operational position. The first engine using only secondary fuel in the first operational position and operates using only primary fuel in the second operational position. The method includes supplying the second engine with primary fuel from the common fuel source without flaring the primary fuel.