A turbofan engine includes a propulsor section that has a propulsor shaft in driving engagement with a propulsor. An epicyclic gear system has a gear mesh lateral stiffness and a gear mesh transverse stiffness. A gear system input defines a gear system input lateral stiffness and a gear system input transverse stiffness. The gear system input lateral stiffness is less than 5% of the gear mesh lateral stiffness. A first turbine section rotates at a first speed, and a second turbine rotates at a second speed that is faster than the first speed. A first performance quantity is defined as the product of the first speed squared and the first area of the first turbine, a second performance quantity is defined as the product of the second speed squared and the second area of the second turbine, and a performance quantity ratio is between 0.5 and 1.5.

A turbofan engine includes a propulsor section that has a propulsor shaft in driving engagement with a propulsor. An epicyclic gear system has a gear mesh lateral stiffness and a gear mesh transverse stiffness. A gear system input defines a gear system input lateral stiffness and a gear system input transverse stiffness. The gear system input lateral stiffness is less than 5% of the gear mesh lateral stiffness. A first turbine section rotates at a first speed, and a second turbine rotates at a second speed that is faster than the first speed. A first performance quantity is defined as the product of the first speed squared and the first area of the first turbine, a second performance quantity is defined as the product of the second speed squared and the second area of the second turbine, and a performance quantity ratio is between 0.5 and 1.5.

A gas turbine engine includes a fan section that includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. A high spool includes a high pressure turbine that drives a high pressure compressor. The high pressure compressor includes a pressure ratio of greater than 6.5 and less than 11.5. A ratio of a product of a pressure ratio of the fan with a pressure ratio of the low pressure compressor pressure to the pressure ratio of the high pressure compressor is greater than 0.35 and less than 0.90. An exhaust gas exit temperature is greater than 900 degrees Fahrenheit and less than 1000 degrees Fahrenheit at maximum take-off.

A gas turbine engine includes a fan section that includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor includes a greater number of stages than the low pressure turbine. A high spool includes a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine stage high pressure compressor and includes a pressure ratio per stage of greater than or equal to 1.20 and less than or equal to 1.33.

A gas turbine engine includes a fan drive turbine driving a low pressure compressor, and driving a gear reduction to in turn drive a fan rotor at a speed slower than the fan drive turbine. The turbine section further includes a high pressure turbine driving the high pressure compressor. The fan drive turbine and low pressure compressor are connected by a shaft and the fan drive turbine, the shaft and the low pressure compressor define a low pressure spool. The gas turbine engine is rated to provide an amount of thrust at maximum takeoff, and a low spool thrust ratio defined as a ratio of a torque on the low pressure spool at maximum takeoff in ft-lbs and the maximum takeoff thrust being defined in lbf, with the low spool torque ratio being greater than or equal to 0.70 ft-lb/lbf, and less than or equal to 1.2 ft-lb/lbf.

A gear reduction drives a fan rotor at a speed slower than a fan drive turbine. The turbine section further includes a high pressure turbine driving a high pressure compressor. The fan drive turbine and low pressure compressor are connected by a shaft and the low pressure turbine. The shaft and the low pressure compressor define a low pressure spool, the low pressure spool has a torque at maximum takeoff defined in ft-lbs and also having a low pressure spool power defined in horsepower and at maximum takeoff, and a ratio of the low pressure spool torque to the low pressure spool power being defined, with the low pressure spool power being defined in horsepower, and the ratio of the low pressure spool torque to the low pressure spool power being greater than or equal to 0.6 ft-lb/hp and less than or equal to 1.2 ft-lb/hp.

A gas turbine engine for an aircraft comprises an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor, wherein a compressor exit temperature is defined as an average temperature of airflow at the exit from the compressor; and a fan located upstream of the engine core, the fan comprising a plurality of fan blades extending from a hub, each fan blade having a leading edge and a trailing edge, wherein a fan rotor entry temperature is defined as an average temperature of airflow across the leading edge of each fan blade at cruise conditions and a fan tip rotor exit temperature is defined as an average temperature of airflow across a radially outer portion of each fan blade at the trailing edge at cruise conditions. A core to fan tip temperature rise ratio is in the range from 2.845 to 3.8.

A dual-flow turbojet engine having a central shaft surrounded by a high-pressure body which rotate about the same longitudinal axis while being independent in rotation, and including a fan driven by the central pressure shaft; a high-pressure compressor and a high-pressure turbine mounted on the high-pressure body; an inter-turbine casing; a low-pressure turbine mounted on a low-pressure rotor surrounding the central shaft; an exhaust casing on which an output cone is mounted; a reduction gear with which the low-pressure rotor drives the central pressure shaft; two bearings mounted on the exhaust casing and respectively receiving the central shaft and the low-pressure rotor; a bearing mounted on the inter-turbine casing and receiving the low-pressure rotor.

A gas turbine engine has a compression system blade ratio defined as the ratio of the height of a fan blade to the height of the most downstream compressor blade in the range of from 45 to 95. This results in an optimum balance between installation benefits, operability, maintenance requirements and engine efficiency when the gas turbine engine is installed on an aircraft.

A planetary gearbox includes a planet carrier, with a planetary gear rotatably disposed on the planet carrier, and a gear that meshes with the planetary gear, as well as a gas turbine engine having such a planetary gearbox. The planet carrier has an oil supply installation including a supply line for oil to an opening. The oil is directed out of the opening in the direction of the planetary gear and/or the gear. The oil supply installation in relation to a primary rotating direction of the planetary gear and/or the gear in front of the opening includes a shielding region which protrudes from an external side of the oil supply installation and which by way of the external side of the oil supply installation on a side that faces the primary rotating direction of the planetary gear and/or the gear, delimits an oil collection groove.