A turbofan engine has a fan drivingly engaged by a shaft for rotation about a rotation axis and having: fan blades circumferentially distributed about the rotation axis and drivingly engaged by the shaft; an ice-accruing feature located on a surface of the fan exposed to an air flow flowing between the fan blades, the ice-accruing feature having a shape providing a non-axisymmetric ice accumulation on the fan to create a rotational imbalance; a balancing feature secured to the fan or to the shaft to counteract the ice-accruing feature such that the fan is rotationally balanced when the fan is free of ice, the balancing feature being located such as to be outside the air flow; an aircraft controller; and a sensor operatively connected to the fan and operable to send a signal to the aircraft controller, the signal indicative of the rotational imbalance caused by the ice-accruing feature.

A turbofan engine has a fan drivingly engaged by a shaft for rotation about a rotation axis and having: fan blades circumferentially distributed about the rotation axis and drivingly engaged by the shaft; an ice-accruing feature located on a surface of the fan exposed to an air flow flowing between the fan blades, the ice-accruing feature having a shape providing a non-axisymmetric ice accumulation on the fan to create a rotational imbalance; a balancing feature secured to the fan or to the shaft to counteract the ice-accruing feature such that the fan is rotationally balanced when the fan is free of ice, the balancing feature being located such as to be outside the air flow; an aircraft controller; and a sensor operatively connected to the fan and operable to send a signal to the aircraft controller, the signal indicative of the rotational imbalance caused by the ice-accruing feature.

A journal support pin to support intermediate gears for use in gas turbine engine comprises a titanium body, and an outer surface outside of the titanium body having a surface hardness that is harder than the body. A gas turbine engine and a method of forming a journal support pin to support intermediate gears for use in gas turbine engine are also disclosed.

A journal support pin to support intermediate gears for use in gas turbine engine comprises a titanium body, and an outer surface outside of the titanium body having a surface hardness that is harder than the body. A gas turbine engine and a method of forming a journal support pin to support intermediate gears for use in gas turbine engine are also disclosed.

A turbine engine includes integrated electric machines in the compressor section and the turbine section to supplement power produced from fuel with electric power. The example compressor section includes a compressor electric motor that is coupled to a compressor generator. The example turbine section includes a turbine electric motor that is coupled to the geared architecture to supplement power driving the fan section. A turbine generator provides electric power to the turbine electric motor.

A turbine engine includes integrated electric machines in the compressor section and the turbine section to supplement power produced from fuel with electric power. The example compressor section includes a compressor electric motor that is coupled to a compressor generator. The example turbine section includes a turbine electric motor that is coupled to the geared architecture to supplement power driving the fan section. A turbine generator provides electric power to the turbine electric motor.

A gas turbine engine includes a fan rotor driven by a fan drive turbine about an axis through a gear reduction. An inner core engine has an inner core engine housing surrounding a compressor section, including a low pressure compressor. A rigid connection between a fan case and the inner core engine includes A-frames rigidly connected at a connection point to the fan case. Fan exit guide vanes rigidly connect to the fan case, and to the inner core engine. A fan intermediate case is positioned forward of a first rotor stage in the low pressure compressor. A rigid structure is connected to the inner core engine and to the fan exit guide vanes. The rigid structure defines a structure moment stiffness. The fan intermediate case defines an intermediate case moment stiffness. A ratio of the structure moment stiffness to the intermediate case moment stiffness is between 5 and 15.

A rotating airfoil assembly including a rotation axis and a plurality of rotating airfoils configured to rotate about the rotation axis. Each rotating airfoil of the rotating airfoils includes a leading edge, a trailing edge, a suction surface between the leading edge and the trailing edge, and a pressure surface between the leading edge and the trailing edge. The suction surface and the pressure surface are positioned on opposite sides of the rotating airfoil such that, when airflows over the suction surface and the pressure surface of the rotating airfoil as the rotating airfoil rotates about the rotation axis, the rotating airfoil generates lift. At least one opening is located on one of the suction surface or the pressure surface. The at least one opening is configured to eject air or to draw air into the opening.

A rotating airfoil assembly including a rotation axis and a plurality of rotating airfoils configured to rotate about the rotation axis. Each rotating airfoil of the rotating airfoils includes a leading edge, a trailing edge, a suction surface between the leading edge and the trailing edge, and a pressure surface between the leading edge and the trailing edge. The suction surface and the pressure surface are positioned on opposite sides of the rotating airfoil such that, when airflows over the suction surface and the pressure surface of the rotating airfoil as the rotating airfoil rotates about the rotation axis, the rotating airfoil generates lift. At least one opening is located on one of the suction surface or the pressure surface. The at least one opening is configured to eject air or to draw air into the opening.

A gear reduction reduces a speed of a fan rotor relative to a speed of a fan drive turbine. A fan case surrounds the fan rotor. A core engine has a compressor section and includes a low pressure compressor. The fan rotor delivers air into a bypass duct defined between the fan case and the core engine. A rigid connection between the fan case and the core engine includes a plurality of aft connecting members rigidly connected to the fan case, and to the core engine. A plurality of fan exit guide vanes are rigidly connected to the fan case, with the fan exit guide vanes including structural fan exit guide vanes which are rigidly connected to the core engine, and non-structural fan exit guide vanes, and the non-structural fan exit guide vanes being provided with an acoustic feature to reduce noise.