A control system may be used to control actuators that actuate movement of flight control surfaces of an aircraft. Each actuator is couplable to a flight control surface and includes a motion control assembly having a hydraulic motor and a drive path from the hydraulic motor to the flight control surface. Each hydraulic motor includes an extend port and a retract port. The system includes a hydraulic control module fluidly connected to the extend port and the retract port of each hydraulic motor and a controller operable to output hydraulic power from the hydraulic control module to the motion control assembly to actuate movement of the flight control surfaces. The controller is configured to identify an actuator that positionally leads the other actuators and reduce hydraulic power to the motion control assembly assigned to such actuator.

An aircraft (5) including a wing (7) having a wing tip device (1) configurable between: a flight configuration and a ground configuration in which the span of the wing (7) is reduced. The aircraft (5) further includes a lock (13) for locking the wing tip device (1) in the flight configuration, and an actuator (3) for unlocking the lock (13) and for subsequently actuating the wing tip device (1) to the ground configuration. The actuator (3) is a two-stage hydraulic actuator, including a first hydraulic actuator stage (21) arranged to unlock the lock and a second hydraulic actuator stage (23) arranged to actuate the wing tip device (1) to the ground configuration. The first and second hydraulic actuator stages (21, 23) are arranged in series such that the second actuator stage (23) is unable to receive a hydraulic input feed until the first actuator stage (21) unlocks the lock (13).

The disclosure relates to a hydraulic system for pressure supply of a hydraulic actuator, comprising a double-acting hydraulic cylinder having two pressure chambers, and a rapid traverse device integrated into a valve unit and configured to hydraulically interconnect the two pressure chambers in a rapid traverse mode and hydraulically separate the two pressure chambers in a normal traverse mode. The valve unit connects to the pressure chambers via first and second connections and comprises a third connection for applying pressure via a hydraulic pump. A displaceably mounted shift piston separates the first and second connections in normal traverse position and connects them, separated from the third connection, in rapid traverse position. The valve unit integrates a preload device having a switchable preload element configured to separate the third connection from the second connection in a locking position, thereby locking the pressure chamber connected to the second connection towards the outside.