This disclosure describes a collective UAV in which multiple UAVs may be coupled together to form the collective UAV. A collective UAV may be used to aerially transport virtually any size, weight or quantity of items, travel longer distances, etc. For example, rather than using one large UAV to carry a larger or heavier item, multiple smaller UAVs may couple together to form a collective UAV that is used to carry the larger or heavier item.

This disclosure describes a collective UAV in which multiple UAVs may be coupled together to form the collective UAV. A collective UAV may be used to aerially transport virtually any size, weight or quantity of items, travel longer distances, etc. For example, rather than using one large UAV to carry a larger or heavier item, multiple smaller UAVs may couple together to form a collective UAV that is used to carry the larger or heavier item.

An electronic aircraft control system and an electronic aircraft control method are provided. In some embodiments, the aircraft control system includes a motor including a rotating shaft, a lever including an axis of rotation, the lever connected to the rotating shaft, wherein the position of the lever is not maintained by a mechanical clutch during normal operations. In some embodiments, the aircraft control system includes a fail-safe system for maintaining mechanical friction of the lever in an event of a failure, a sensor identifying a position of the lever, and a transmitter transmitting the lever position to a controller, the controller adjusting an aircraft performance device based on the received lever position. In some embodiments, the motor provides a torque on the lever. In some embodiments, the fail-safe system includes shear pins configured to break when a sufficient amount of manual torque is applied to the lever.

An electronic aircraft control system and an electronic aircraft control method are provided. In some embodiments, the aircraft control system includes a motor including a rotating shaft, a lever including an axis of rotation, the lever connected to the rotating shaft, wherein the position of the lever is not maintained by a mechanical clutch during normal operations. In some embodiments, the aircraft control system includes a fail-safe system for maintaining mechanical friction of the lever in an event of a failure, a sensor identifying a position of the lever, and a transmitter transmitting the lever position to a controller, the controller adjusting an aircraft performance device based on the received lever position. In some embodiments, the motor provides a torque on the lever. In some embodiments, the fail-safe system includes shear pins configured to break when a sufficient amount of manual torque is applied to the lever.

In an asymmetric operating regime, a first engine is operating in an active mode to provide motive power to an aircraft while a second engine is operating in a standby mode and de-clutched from a gearbox of the aircraft. In response to an emergency exit request, the second engine’s speed is increased, at a maximum permissible rate, to a re-clutching speed while increasing the first engine’s power output at a maximum permissible rate. When the re-clutching speed is reached, the second engine’s power output is increased at a maximum permissible rate. In response to a normal exit request, the second engine’s speed is increased to the re-clutching speed at a rate lower than the maximum permissible rate. When the re-clutching speed is reached, the second engine’s power output is increased at a rate lower than the maximum permissible rate.

A power management system for a multi engine rotorcraft having a main rotor system with a main rotor speed. The power management system includes a first engine that provides a first power input to the main rotor system. A second engine selectively provides a second power input to the main rotor system. The second engine has at least a zero power input state and a positive power input state. A power anticipation system is configured to provide the first engine with a power adjustment signal in anticipation of a power input state change of the second engine during flight. The power adjustment signal causes the first engine to adjust the first power input to maintain the main rotor speed within a predetermined rotor speed threshold range during the power input state change of the second engine.

A power management system for a multi engine rotorcraft having a main rotor system with a main rotor speed. The power management system includes a first engine that provides a first power input to the main rotor system. A second engine selectively provides a second power input to the main rotor system. The second engine has at least a zero power input state and a positive power input state. A power anticipation system is configured to provide the first engine with a power adjustment signal in anticipation of a power input state change of the second engine during flight. The power adjustment signal causes the first engine to adjust the first power input to maintain the main rotor speed within a predetermined rotor speed threshold range during the power input state change of the second engine.

A hydraulic propulsion system is disclosed which includes an input interface configured to receive mechanical power from a power source, a pressure source comprising one or more fixed or variable displacement pumps coupled to the input interface and adaptable to convert mechanical power to hydraulic power and controlling outlet pressure of the pressure source (system pressure), one or more variable displacement motors coupled to the pressure source via a corresponding high-pressure line configured to be mechanically coupled to one or more aerodynamic rotors of an aircraft and comprising a closed loop speed control arrangement in response to a commanded rotor speed, and a controller configured to control the speed of one or more variable displacement motors by providing a control signal for controlling the system pressure.

A hydraulic propulsion system is disclosed which includes an input interface configured to receive mechanical power from a power source, a pressure source comprising one or more fixed or variable displacement pumps coupled to the input interface and adaptable to convert mechanical power to hydraulic power and controlling outlet pressure of the pressure source (system pressure), one or more variable displacement motors coupled to the pressure source via a corresponding high-pressure line configured to be mechanically coupled to one or more aerodynamic rotors of an aircraft and comprising a closed loop speed control arrangement in response to a commanded rotor speed, and a controller configured to control the speed of one or more variable displacement motors by providing a control signal for controlling the system pressure.

Methods and systems for operating an engine are provided. An engine core temperature is monitored. When the engine core temperature is below an engine thermal limit adjusted for a level of deterioration of the engine, an output power of the engine is set in accordance with a reference power based on non-thermal limits of the engine. When the engine core temperature is near or above the engine thermal limit adjusted for the level of deterioration of the engine, the output power of the engine is set to a value lower than the reference power based on non-thermal limits of the engine to reduce the engine core temperature.