An electronic control system (35) for a turbopropeller engine (2) having a gas turbine (20) and a propeller assembly (3) coupled to the gas turbine (20), the control system (35) implementing a propeller control unit (PEC) to control propeller operation based on a pilot input request, via generation of a driving quantity (I.sub.p) for an actuation assembly (29) designed to adjust a pitch angle () of propeller blades (10). The control unit engages a mechanical lock determining a minimum flight value for the pitch angle during a flight operating mode, and disengages the mechanical lock and controls the pitch angle below the minimum flight value, up to a minimum ground value lower than the minimum flight value, during a ground operating mode; the propeller control unit, during a transition from the ground operating mode to the flight operating mode, engages the mechanical lock, thereby causing an increase of the pitch angle towards the minimum flight value independently from the control action. In particular, the control unit anticipates the increase of the pitch angle in a time period (T) before the mechanical lock engagement due to transition from the ground operating mode to the flight operating mode.

A propeller includes a blade free to rotate. A first stop is positioned to mechanically engage one or both of a first portion of the blade and a first structure coupled to the blade when the blade is in a first position at a first end of the rotational range of motion. A second stop is positioned to mechanically engage one or both of a second portion of the blade and a second structure coupled to the blade when the blade is in a second position at a second end of the defined rotational range. The blade rotates to the first position against the first stop when the propeller is rotated in a first direction and to the second position against the second stop when the propeller is rotated in a second direction.

The invention relates to a fan module with variable-pitch blades for a turbomachine, comprising a rotor (2) carrying blades (3), a stationary housing (7), a mechanism (11, 12, 13, 14, 20) for regulating the pitch of the blades (3), which is connected to the rotor, and a control means (16, 17) mounted on the stationary housing (7) and comprising a control part (18) that can be moved in translation according to an axis (X) of rotation of the rotor (2), and a bearing (19) for load transfer between the control part (18) and said mechanism, characterised in that it also comprises a stationary track (23) supporting the elastic restoring means (26, 27) which are arranged so as to exert an axial restoring force on the control part (18) towards a determined position, preferably corresponding to the blade (3) feathering.

A propeller includes a blade free to rotate. A first stop is positioned to mechanically engage one or both of a first portion of the blade and a first structure coupled to the blade when the blade is in a first position at a first end of the rotational range of motion. A second stop is positioned to mechanically engage one or both of a second portion of the blade and a second structure coupled to the blade when the blade is in a second position at a second end of the defined rotational range. The blade rotates to the first position against the first stop when the propeller is rotated in a first direction and to the second position against the second stop when the propeller is rotated in a second direction.

Apparatus, systems, and methods are contemplated for electric powered vertical takeoff and landing (eVTOL) aircraft. Such are craft are engineered to carry safely carry at least 500 pounds (approx. 227 kg) using a few (e.g., 2-4) rotors, generally variable speed rigid (non-articulated) rotors. It is contemplated that one or more rotors generate a significant amount of lift (e.g., 70%) during rotorborne flight (e.g., vertical takeoff, hover, etc), and tilt to provide forward propulsion during wingborne flight. The rotors preferably employ individual blade control, and are battery powered. The vehicle preferably flies in an autopilot or pilotless mode and has a relatively small (e.g., less than 45 diameter) footprint.

Methods and systems for feathering a propeller are described herein. A solenoid is configured to cause a propeller to feather when the solenoid is energized. An electronic controller is connected to the solenoid through a first electrical connection for energizing the solenoid to feather the propeller. A secondary mechanism is connected to the solenoid through a second electrical connection for energizing the solenoid to feather the propeller. The second electrical connection is independent from the first electrical connection.

A pitch actuation system for a turbine engine propeller includes an actuator with movable part configured to rotate the blades of the propeller relative to the blade pitch axes. The actuator includes a transmission screw that is rotatable and movable in translation along a longitudinal axis, and a nut that engages the screw to move in translation along the longitudinal axis to adjust the pitch of the propeller blades. The actuator further includes non-rotatable decoupler for decoupling the rotation between the propeller and the nut. A blade feathering device has at least one electric drive motor and is configured to translate a member along the longitudinal axis. A blade pitch control device includes at least one electric motor configured to drive a rotor about the longitudinal axis, wherein that rotation rotates the screw and transmits translation of the member.

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 device for locking the pitch and for feathering adjustable-pitch fan blades of a turbine engine propeller, the device including an actuator having at least one movable portion designed to be coupled to pivots of the fan blades of the propeller in order to modify their pitch angle when it slides, a movable part having first mechanical device suitable for co-operating with the actuator when in a fan blade pitch-unlocking position in order to enable the actuator movable portion to slide over an extended actuator stroke; and second mechanical device suitable for co-operating with the actuator when in a fan blade pitch-locking position in order to enable the actuator movable portion to slide over an actuator stroke that is shorter than the extended actuator stroke, and an actuator.

An aircraft comprising a fuselage and propelled by a turbine engine having two coaxial and contrarotating fans, the turbine engine comprising a power turbine having two contrarotating rotors, one of which drives a fan upstream from the turbine, the other a fan downstream from the turbine, each fan comprising a ring of blades, and the assembly of the fans and the power turbine being incorporated at the rear of the fuselage, in the extension of same. The aircraft comprises, for at least one of the fans, a device for blocking the rotation of the fan and a device configured to modify the pitch of the blades of the fan in such a way as to make it operate as a flow straightener with respect to the other fan.