According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

Disclosed is an autopilot system for a helicopter, the helicopter having: a cyclic and a collective that are physically coupled to helicopter actuators that control cyclic and collective pitch of main rotor blades of the helicopter and anti-torque pedals that are physically coupled to helicopter actuators that control the pitch of tail rotor blades of the helicopter; and at least one servomechanism configured to amplify force applied by the pilot to the cyclic, collective and/or anti-torque pedals; wherein the autopilot system comprises an autopilot actuator configured to: in an autopilot mode, control direction or orientation of the helicopter by applying force to a control link that is physically coupled to one of the helicopter actuators; and in a manual mode, provide stability or control augmentation by applying a force on one of the cyclic, the collective or one or both of the anti-torque pedals to influence the pilot's inputs to urge the helicopter away from a particular flight condition dependent on monitored aircraft parameters.

Disclosed is an autopilot system for a helicopter, the helicopter having: a cyclic and a collective that are physically coupled to helicopter actuators that control cyclic and collective pitch of main rotor blades of the helicopter and anti-torque pedals that are physically coupled to helicopter actuators that control the pitch of tail rotor blades of the helicopter; and at least one servomechanism configured to amplify force applied by the pilot to the cyclic, collective and/or anti-torque pedals; wherein the autopilot system comprises an autopilot actuator configured to: in an autopilot mode, control direction or orientation of the helicopter by applying force to a control link that is physically coupled to one of the helicopter actuators; and in a manual mode, provide stability or control augmentation by applying a force on one of the cyclic, the collective or one or both of the anti-torque pedals to influence the pilot's inputs to urge the helicopter away from a particular flight condition dependent on monitored aircraft parameters.

Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Disclosed are systems, methods, and apparatus for actively adjusting the shape of a propeller blade of an aerial vehicle during operation of the aerial vehicle. For example, the propeller blade may have one or more joints that adjust to alter the shape of the propeller blade. The altered shape of the propeller blade causes the propeller to generate different frequencies of sound as it rotates. By altering multiple propeller blades of the aerial vehicle, the different sounds generated by the different propeller blades may effectively cancel or reduce the total sound generated by the aerial vehicle, and/or alter the total frequency generated.

Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Disclosed are systems, methods, and apparatus for actively adjusting the shape of a propeller blade of an aerial vehicle during operation of the aerial vehicle. For example, the propeller blade may have one or more joints that adjust to alter the shape of the propeller blade. The altered shape of the propeller blade causes the propeller to generate different frequencies of sound as it rotates. By altering multiple propeller blades of the aerial vehicle, the different sounds generated by the different propeller blades may effectively cancel or reduce the total sound generated by the aerial vehicle, and/or alter the total frequency generated.

A system for controlling an electromechanical actuator for setting a collective offset for a helicopter on a blade-specific basis, wherein the system comprises at least one actuator, the length and position of which can be adjusted electromechanically within a mechanically limited range, a power electronics that is configured to adjust the actuator by means of a servomotor in two directions, specifically toward a positive collective offset or toward a negative collective offset, and a first microelectronics system that is configured to control the power electronics such that positive and negative collective offsets can be set. The system also includes a second microelectronics system, which is configured to override the actuation of the first microelectronics system in order to act on the adjustment of the actuator, and by a first control line, which is configured to activate or deactivate the second microelectronics system through an external electrical signal.

A system for controlling an electromechanical actuator for setting a collective offset for a helicopter on a blade-specific basis, wherein the system comprises at least one actuator, the length and position of which can be adjusted electromechanically within a mechanically limited range, a power electronics that is configured to adjust the actuator by means of a servomotor in two directions, specifically toward a positive collective offset or toward a negative collective offset, and a first microelectronics system that is configured to control the power electronics such that positive and negative collective offsets can be set. The system also includes a second microelectronics system, which is configured to override the actuation of the first microelectronics system in order to act on the adjustment of the actuator, and by a first control line, which is configured to activate or deactivate the second microelectronics system through an external electrical signal.

A rotor for a hover-capable aircraft is described that comprises: a hub rotatable about a first axis and at least two blades hinged to the hub; each blade comprises a main portion hinged to the hub and a tip portion, which is arranged radially outermost with respect to first axis with respect to the corresponding main portion; the tip portion of each blade is movable with respect to the corresponding main portion of that blade; the tip portion of each blade is selectively movable with respect to the corresponding main portion of that blade between a first position, in which it defines a dihedral or anhedral angle with respect to the corresponding main portion; and a second position, in which it defines a positive or negative sweep angle with respect to the corresponding main portion.

A rotor for a hover-capable aircraft is described that comprises: a hub rotatable about a first axis and at least two blades hinged to the hub; each blade comprises a main portion hinged to the hub and a tip portion, which is arranged radially outermost with respect to first axis with respect to the corresponding main portion; the tip portion of each blade is movable with respect to the corresponding main portion of that blade; the tip portion of each blade is selectively movable with respect to the corresponding main portion of that blade between a first position, in which it defines a dihedral or anhedral angle with respect to the corresponding main portion; and a second position, in which it defines a positive or negative sweep angle with respect to the corresponding main portion.