Redundant control system for an air to air refuelling system

A redundant control system for keeping hose tension during a contact operation in a hose and drogue refuelling system, the redundant control system comprising:

• two motors configured independently to actuate a hose drum unit for keeping a hose in tension during a contact operation when one of the two motors is actuated;
• two control units, each of the two control units comprising two computing devices configured to control actuation of any one of the two motors;
• actuating means configured to actuate one of the two motors based at least on an operation of the computing devices, on a status of the two motors, or both;
• and,
• a communication network connecting the computing devices to each other and the computing devices to the actuating means,
• wherein for each of the two control units one computing device is configured as a control computing device for controlling an actuation of one motor, and the other computing device is configured as a monitor computing device for monitoring a motor actuation control performed by the control computing device, and
• wherein for the contact operation in the hose and drogue refuelling system, the redundant control system is configured to actuate one motor being controlled by one of the two control units and in an event of a failure in the redundant control system, the redundant control system is reconfigured to actuate a fault-free motor controlled by a fault-free control unit or a combination of control units.