Method of operating a lubrication system for a turbine engine

A turbine engine for an aircraft, the turbine engine comprising:

• a fan having a fan shaft, the fan generating compressed air during a normal operation of the turbine engine;
• a hydraulic system including one or more hydraulic fluid reservoirs for storing a hydraulic fluid, one or more hydraulic lines in fluid communication with the one or more hydraulic fluid reservoirs, and one or more hydraulic control systems, the hydraulic system being configured to provide the hydraulic fluid from the one or more hydraulic fluid reservoirs to the one or more hydraulic control systems to actuate one or more components in the turbine engine;
• a fuel system containing a fuel, the fuel system being configured to provide a flow of the fuel;
• and
• a lubrication system configured to provide a lubricant to one or more rotating components within the turbine engine, the lubrication system comprising:
• one or more tanks to store the lubricant;
• a primary lubrication system that supplies lubricant to the one or more rotating components from the one or more tanks during the normal operation of the turbine engine;
• and
• an auxiliary lubrication system comprising an auxiliary pump and a clutch, and the auxiliary pump being drivingly coupled to the fan shaft when the clutch is in an engaged state,
• wherein the clutch is in the engaged state when at least one of a detected fuel pressure of the fuel in the fuel system is less than a fuel pressure threshold or a detected hydraulic pressure of the hydraulic fluid in the hydraulic system is less than a hydraulic pressure threshold.