A pitch control system configured to vary a pitch angle of at least one of a plurality of propeller blades of a propeller system is provided including a switch movable between a neutral position and a plurality of non-neutral positions. Movement of the switch to a first non-neutral position generates a command to move the propeller blades in a first direction. Movement of the switch to a second non-neutral position generates a command to move the propeller blades in a second direction. Movement of the switch to a third non-neutral position generates a command to move the propeller blades to a zero thrust position.

A pitch control system configured to vary a pitch angle of at least one of a plurality of propeller blades of a propeller system is provided including a switch movable between a neutral position and a plurality of non-neutral positions. Movement of the switch to a first non-neutral position generates a command to move the propeller blades in a first direction. Movement of the switch to a second non-neutral position generates a command to move the propeller blades in a second direction. Movement of the switch to a third non-neutral position generates a command to move the propeller blades to a zero thrust position.

Methods and systems for slowing down an aircraft having a propeller. The method comprises operating the propeller at a reference speed with the propeller blades in a first position, applying a load to the propeller to slow down a rotational speed of the propeller when the propeller is in a windmilling state or just before the propeller enters the windmilling state, adjusting the propeller blades to a second position in response to the load being applied, to increase the rotational speed of the propeller back towards the reference speed, and operating the propeller at the reference speed with the propeller blades in the second position.

A control system for controlling at least one propeller of a compound rotorcraft, the control system generating a control order for collectively controlling a pitch of the blades of at least one propeller. According to the disclosure, the control system comprises: a first piloting control for generating a first control setpoint; a second piloting control for at least generating a second control setpoint different from first control setpoint; and a control unit configured to generate control order depending on the first control setpoint and second control setpoint, the control unit implementing a control law generating the control order as a function of first control setpoint and the second control setpoint.

Vertical takeoff and landing vehicles (VTOLs) of the type used for the point-to-point delivery and transport of payloads (e.g., packages, equipment, etc.) and personnel, are significantly stabilized at least during takeoff and landing with present aspects significantly ameliorating or significantly eliminating destabilizing effects, including ground effect, during VTOL takeoff and/or landing.

A pitch control system configured to vary a pitch angle of a plurality of propeller blades of a propeller system is provided including a motor having a motor shaft configured to rotate about an axis. A rotary switch having a tab protruding generally outwardly is coupled to the motor shaft and is configured to move between a first position and a second position. The pitch control system also includes a position sensor configured to monitor the position of the rotary switch. The position of the rotary switch is proportional to the pitch angle of the plurality of propeller blades.

A pitch control system configured to vary a pitch angle of a plurality of propeller blades of a propeller system is provided including a motor having a motor shaft configured to rotate about an axis. A rotary switch having a tab protruding generally outwardly is coupled to the motor shaft and is configured to move between a first position and a second position. The pitch control system also includes a position sensor configured to monitor the position of the rotary switch. The position of the rotary switch is proportional to the pitch angle of the plurality of propeller blades.

A lubrication system for a device located between an internal shaft and an external shaft of an aircraft turbine, that are free to rotate, concentric and arranged at least partially one around the other, is provided. The lubrication system includes an annular element provided with an external groove and being mounted integral with the external shaft, the external groove being supplied with lubricant from a fixed part of the turbine; and a grooved element mounted integral with the internal shaft, the grooved element having a relief which directs a lubricant in contact with its external surface along a longitudinal direction when the internal shaft is rotating. The external groove is in fluid communication with an external surface of the grooved element through at least two conduits arranged through the external shaft.

The lengths and/or chords and/or pitches of wind turbine or propeller blades are individually established, so that a first blade can have a length/chord/pitch that is different at a given time to the length/chord/pitch of a second blade to optimize performance and/or to equalize stresses on the system.

The lengths and/or chords and/or pitches of wind turbine or propeller blades are individually established, so that a first blade can have a length/chord/pitch that is different at a given time to the length/chord/pitch of a second blade to optimize performance and/or to equalize stresses on the system.