A method and system for operating a gas turbine engine coupled to an aircraft propeller are described herein. The method comprises detecting a command for unfeathering the propeller, inhibiting shaft shear detection logic in response to detecting the command for unfeathering the propeller, detecting completion of the unfeathering of the propeller, and enabling the shaft shear detection logic in response to detecting the completion of the propeller unfeathering.

A pitch control system characterized by a hub with at least two blade housings on the hub that are disposed around the hub axis. The blade housings have corresponding blades that engage with them. The blades spiral along housing longitudinal axes toward and away from the hub axis about a segment of helical path to effect a change in the pitch of each blade. One or more elastic members draw the blades toward the hub axis, either directly or indirectly. There are pitch mechanisms effective to facilitate blades to spiral around housing-longitudinal axes. A blade will spiral away from the hub axis when the centrifugal force exerted on the blade exceeds the opposing elastic force in the housing-longitudinal direction (neglecting other forces). Conversely, blades spiral toward the hub axis when said centrifugal force is less than said elastic force. There is an imaginary plane orthogonal to the hub axis. Housing-longitudinal axes have angles with respect to the imaginary plane of not more than 30 degrees.

There is provided a blade angle feedback assembly for a propeller of an aircraft engine. The propeller is rotatable about an axis and has propeller blades rotatable about respective spanwise axes to adjust a blade angle thereof. The blade angle feedback assembly comprises a feedback ring having a plurality of position markers disposed thereon, at least one sensor configured to provide feedback on the blade angle of the propeller blades by detecting a relative movement between the feedback ring and the at least one sensor, and at least one shielding element provided between the feedback ring and the propeller, the at least one shielding element configured to shield the feedback ring from electromagnetism.

There is provided a blade angle feedback assembly for a propeller of an aircraft engine. The propeller is rotatable about an axis and has propeller blades rotatable about respective spanwise axes to adjust a blade angle thereof. The blade angle feedback assembly comprises a feedback ring having a plurality of position markers disposed thereon, at least one sensor configured to provide feedback on the blade angle of the propeller blades by detecting a relative movement between the feedback ring and the at least one sensor, and at least one shielding element provided between the feedback ring and the propeller, the at least one shielding element configured to shield the feedback ring from electromagnetism.

A propeller arrangement for an aircraft, and an aircraft having a propeller arrangement of said type, are specified. The propeller arrangement has a first propeller blade and a second propeller blade, and a propeller mount on which both the first propeller blade and the second propeller blade are mounted. The propeller arrangement furthermore has a drive shaft with a holding unit, and a first connecting unit. The first propeller blade is rotatable about a first axis of rotation and the second propeller blade is rotatable about a second axis of rotation. The propeller mount is pivotable about a pivot axis. The first connecting unit is coupled to the first propeller blade and to the holding unit, such that, in the event of a pivoting of the propeller mount about the pivot axis, the first propeller blade is set in rotational motion about the first axis of rotation.

A propeller arrangement for an aircraft, and an aircraft having a propeller arrangement of said type, are specified. The propeller arrangement has a first propeller blade and a second propeller blade, and a propeller mount on which both the first propeller blade and the second propeller blade are mounted. The propeller arrangement furthermore has a drive shaft with a holding unit, and a first connecting unit. The first propeller blade is rotatable about a first axis of rotation and the second propeller blade is rotatable about a second axis of rotation. The propeller mount is pivotable about a pivot axis. The first connecting unit is coupled to the first propeller blade and to the holding unit, such that, in the event of a pivoting of the propeller mount about the pivot axis, the first propeller blade is set in rotational motion about the first axis of rotation.

A method of providing torque protection and/or thrust protection for the or each propeller of a hybrid helicopter. The hybrid helicopter includes a control system connected to the blades of each propeller and a thrust control configured to generate an order for modifying a pitch of the blades, which order is transmitted to the control system, the propeller(s) being driven in rotation by a mechanical transmission system of the hybrid helicopter. The method includes a step of having the control system keep the pitch of the blades of a propeller within at least one control envelope relating to a thrust generated by the propeller or to a torque exerted in the mechanical transmission system. In this way, the pitch of the blades of each propeller is kept between a lower limit and an upper limit of the control envelope.

A blade angle feedback ring assembly for an aircraft propeller rotatable about a longitudinal axis and having an adjustable blade angle is provided. A feedback ring is coupled to the propeller to rotate therewith and to move along a longitudinal axis with adjustment of the blade angle. A plurality of rods are coupled to the feedback ring and extending along a direction substantially parallel to the longitudinal axis, the rods configured to support the feedback ring for longitudinal sliding movement along the longitudinal axis with adjustment of the blade angle. At least one shielding element is provided between the feedback ring and the propeller for shielding the feedback ring from electromagnetism.

A blade angle feedback ring assembly for an aircraft propeller rotatable about a longitudinal axis and having an adjustable blade angle is provided. A feedback ring is coupled to the propeller to rotate therewith and to move along a longitudinal axis with adjustment of the blade angle. A plurality of rods are coupled to the feedback ring and extending along a direction substantially parallel to the longitudinal axis, the rods configured to support the feedback ring for longitudinal sliding movement along the longitudinal axis with adjustment of the blade angle. At least one shielding element is provided between the feedback ring and the propeller for shielding the feedback ring from electromagnetism.

The present disclosure is directed to a method for determining an aircraft minimum low pitch setting for a propeller assembly and minimum gas generator idle speed for a gas generator, in which the propeller assembly and the gas generator together comprise a gas turbine engine. The method comprises determining, via one or more controllers, an operating condition of the aircraft based at least on a weight on wheels (WoW) signal and a throttle lever position. The WoW signal produces a first mode or a second mode different from the first mode, and the throttle lever position defines at least a takeoff position and an idle power position.