Abstract: A turbofan engine including a fan section including a plurality of fan blades rotatable about an axis, a compressor including a plurality of compressor blades, a turbine including a plurality of turbine blades and a geared architecture driven by the turbine for driving the fan section at a speed and direction different than the turbine is disclosed. A rub strip proximate at least one of the compressor blades, the turbine blades and the fan blades slows rotation when engaged. The rub strip generates a torque opposing rotation when in an engaged condition that is between 2 and 6 times a torque encountered in a non-engaged condition.

Abstract: A fan case for a gas turbine engine includes a fan case surrounding a fan with fan blades. A liner is disposed between the fan case and the fan and is spaced a radial distance from the fan case. A torque stop is arranged between the fan case and the liner. A method for reducing fan case liner loads is also disclosed.

Abstract: A fan shaft includes a first end, a second end, and an axis, the fan shaft and configured to be coupled to a gear assembly of a gas turbine engine at the first end and to a fan more proximal to the second end than the first end such that in response to being coupled, the fan shaft can transfer torque from the gear assembly to the fan. At least one axial portion of the fan shaft satisfies the relationship 0.55 ? T * C J * ? ? 0.95 , where T represents peak torque during fan blade off, C represents a distance from a centerline of the gas turbine engine to an outer fiber of the fan shaft, J represents a polar moment of inertia of the fan shaft, and ? represents yield stress in shear of the fan shaft.

Abstract: A fan shaft includes a first end, a second end, and an axis, the fan shaft and configured to be coupled to a gear assembly of a gas turbine engine at the first end and to a fan more proximal to the second end than the first end such that in response to being coupled, the fan shaft can transfer torque from the gear assembly to the fan. At least one axial portion of the fan shaft satisfies the relationship 0.55 ? T * C J * ? ? 0.95 , where T represents peak torque during fan blade off, C represents a distance from a centerline of the gas turbine engine to an outer fiber of the fan shaft, J represents a polar moment of inertia of the fan shaft, and ? represents yield stress in shear of the fan shaft.

Abstract: A turbofan engine including a fan section including a plurality of fan blades rotatable about an axis, a compressor including a plurality of compressor blades, a turbine including a plurality of turbine blades and a geared architecture driven by the turbine for driving the fan section at a speed and direction different than the turbine is disclosed. A rub strip proximate at least one of the compressor blades, the turbine blades and the fan blades slows rotation when engaged. The rub strip generates a torque opposing rotation when in an engaged condition that is between 2 and 6 times a torque encountered in a non-engaged condition.

Abstract: A fan case for a gas turbine engine includes a fan case surrounding a fan with fan blades. A liner is disposed between the fan case and the fan and is spaced a radial distance from the fan case. A torque stop is arranged between the fan case and the liner. A method for reducing fan case liner loads is also disclosed.