Abstract: A method of extracting work from a convertible gas turbine engine having a core flowpath and a bypass flowpath. The method comprises operating the convertible gas turbine engine at a first volumetric flow rate through the core flowpath and a second volumetric flow rate through the bypass flowpath to produce a first work output of the convertible gas turbine engine; extracting the first work output via an unshrouded fan and a shaft at a first fan to shaft extraction ratio; altering the second volumetric flowrate through the bypass flowpath while maintaining the first work output; and extracting the first work output via an unshrouded fan and a shaft at a second fan to shaft extraction ratio.

Abstract: A system for starting a turbine engine. The system may comprise a gearbox, a first starter, and a second starter. The gearbox may have a gearbox input shaft. The gearbox may be coupled to the turbine engine. The gearbox input shaft may be rotatively coupled to a spool of the turbine engine. The first starter may be coupled to the gearbox input shaft. The second starter may have a second-starter output shaft. The second-starter output shaft may be coaxial with the gearbox input shaft. The second starter may be coupled to the gearbox input shaft through the first starter.

Abstract: A system for starting a turbine engine is provided. The system may comprise a gearbox, an electric starter, and an air turbine starter. The gearbox may have a gearbox input shaft. The gearbox may be coupled to the turbine engine. The gearbox input shaft may be coupled to a spool of the turbine engine. The electric starter may have an electric-starter shaft. The electric-starter shaft may be coupled to the gearbox input shaft. The air turbine starter may have an air-turbine-starter shaft. The air-turbine-starter shaft may be coupled to the gearbox input shaft. The electric-starter shaft and the air-turbine-starter shaft may be radially displaced, circumferentially displaced, or both radially and circumferentially displaced, with respective to an axis of the turbine engine, from one another. The electric starter may be a starter-generator connected alternatively between an auxiliary power source and an auxiliary load.

Abstract: A system for starting a turbine engine is provided. The system may comprise an gearbox, and electric starter, and an air turbine starter. The gearbox may have a gearbox input shaft. The gearbox input shaft may be coupled to a turbine engine. The gearbox input shaft may be rotationally coupled to a spool of the turbine engine. The electric starter may be coupled to the gearbox input shaft. The air turbine starter may be coupled to the gearbox input shaft. The electric starter and the air turbine starter may be separated by the gearbox. The electric starter may be a starter-generator connected alternatively between an auxiliary power source and an auxiliary load.

Abstract: A system for starting a turbine engine is provided. The system may comprise a gearbox, a first starter, and a second starter. The gearbox may have an gearbox input shaft. The gearbox input shaft may be rotationally coupled to a spool of the turbine engine. The first starter may have a first-starter shaft. The second starter may have a second-starter shaft. The second-starter shaft may be coaxial with the first-starter shaft. The first starter and the second starter may each be coupled to the gearbox input shaft independently of one another.

Abstract: A system for starting a turbine engine is provided. The system may comprise a gearbox, a first starter, and a second starter. The gearbox may have an gearbox input shaft. The gearbox input shaft may be rotationally coupled to a spool of the turbine engine. The first starter may have a first-starter shaft. The second starter may have a second-starter shaft. The second-starter shaft may be coaxial with the first-starter shaft. The first starter and the second starter may each be coupled to the gearbox input shaft independently of one another.

Abstract: A system for starting a turbine engine. The system may comprise a gearbox, a first starter, and a second starter. The gearbox may have a gearbox input shaft. The gearbox may be coupled to the turbine engine. The gearbox input shaft may be rotatively coupled to a spool of the turbine engine. The first starter may be coupled to the gearbox input shaft. The second starter may have a second-starter output shaft. The second-starter output shaft may be coaxial with the gearbox input shaft. The second starter may be coupled to the gearbox input shaft through the first starter.

Abstract: A system for starting a turbine engine is provided. The system may comprise an gearbox, and electric starter, and an air turbine starter. The gearbox may have a gearbox input shaft. The gearbox input shaft may be coupled to a turbine engine. The gearbox input shaft may be rotationally coupled to a spool of the turbine engine. The electric starter may be coupled to the gearbox input shaft. The air turbine starter may be coupled to the gearbox input shaft. The electric starter and the air turbine starter may be separated by the gearbox. The electric starter may be a starter-generator connected alternatively between an auxiliary power source and an auxiliary load.

Abstract: A system for starting a turbine engine is provided. The system may comprise a gearbox, an electric starter, and an air turbine starter. The gearbox may have a gearbox input shaft. The gearbox may be coupled to the turbine engine. The gearbox input shaft may be coupled to a spool of the turbine engine. The electric starter may have an electric-starter shaft. The electric-starter shaft may be coupled to the gearbox input shaft. The air turbine starter may have an air-turbine-starter shaft. The air-turbine-starter shaft may be coupled to the gearbox input shaft. The electric-starter shaft and the air-turbine-starter shaft may be radially displaced, circumferentially displaced, or both radially and circumferentially displaced, with respective to an axis of the turbine engine, from one another. The electric starter may be a starter-generator connected alternatively between an auxiliary power source and an auxiliary load.

Abstract: A method of extracting work from a convertible gas turbine engine having a core flowpath and a bypass flowpath. The method comprises operating the convertible gas turbine engine at a first volumetric flow rate through the core flowpath and a second volumetric flow rate through the bypass flowpath to produce a first work output of the convertible gas turbine engine; extracting the first work output via an unshrouded fan and a shaft at a first fan to shaft extraction ratio; altering the second volumetric flowrate through the bypass flowpath while maintaining the first work output; and extracting the first work output via an unshrouded fan and a shaft at a second fan to shaft extraction ratio.

Abstract: A method of extracting work from a convertible gas turbine engine having a core flowpath and a bypass flowpath. The method comprises operating the convertible gas turbine engine at a first volumetric flow rate through the core flowpath and a second volumetric flow rate through the bypass flowpath to produce a first work output of the convertible gas turbine engine; extracting the first work output via an unshrouded fan and a shaft at a first fan to shaft extraction ratio; altering the second volumetric flowrate through the bypass flowpath while maintaining the first work output; and extracting the first work output via an unshrouded fan and a shaft at a second fan to shaft extraction ratio.

Abstract: A method of extracting work from a convertible gas turbine engine having a core flowpath and a bypass flowpath. The method comprises operating the convertible gas turbine engine at a first volumetric flow rate through the core flowpath and a second volumetric flow rate through the bypass flowpath to produce a first work output of the convertible gas turbine engine; extracting the first work output via an unshrouded fan and a shaft at a first fan to shaft extraction ratio; altering the second volumetric flowrate through the bypass flowpath while maintaining the first work output; and extracting the first work output via an unshrouded fan and a shaft at a second fan to shaft extraction ratio.