Method of operating a lubrication system for a turbine engine

A method of operating a lubrication system for a turbine engine having a fan and one or more rotating components, the lubrication system including a primary lubrication system and an auxiliary lubrication system, the method comprising:

• supplying lubricant to the one or more rotating components from the primary lubrication system during a normal operation of the turbine engine;
• determining whether at least one of a fuel pressure in the turbine engine is less than a fuel pressure threshold or a hydraulic pressure in the turbine engine is less than a hydraulic pressure threshold;
• and
• activating the auxiliary lubrication system to supply the lubricant to the one or more rotating components from the auxiliary lubrication system when the at least one of the fuel pressure in the turbine engine is less than the fuel pressure threshold or the hydraulic pressure in the turbine engine is less than the hydraulic pressure threshold.