Abstract: Components, such as bearings, of gas turbine engines especially for aircraft are lubricated by a lubricant supply system including a main lubricant circulating circuit and an auxiliary lubricant circulating circuit for assuring a sufficient lubricant supply to the lubricating chamber or chambers under all operating conditions including those causing extremely rapid and locally differing displacements of the lubricant fluid in its supply tank. The main lubricant circulating circuit with its pumps, lubricating chamber or chambers, cooler, air separator and accumulator is operatively connected to the component being lubricated and is effective during normal and critical flight conditions. The auxiliary circulatory circuit with its lubricant supply tank and its pump is operatively connected to the main circulatory circuit for supplying lubricant into the main circuit.