Noise cancelling is particularly effective against aircraft engine noise. It is mainly used in aircraft engine oil chip detection systems. The LM2500 is a derivative of the General Electric CF6 aircraft engine. Temperature has significant effects on the operational efficiency of an aircraft engine. This is a list of the variants of the Lycoming O-360 aircraft engine. Delco was also one of the manufacturers that produced the Liberty aircraft engine. Especially interesting is its use as an experimental aircraft engine. The aircraft engine factory Motor Sich has its base here. Hirth's joints were first used in aircraft engine crankshafts. AM-35 was a 1930s Soviet piston aircraft engine. This is a list of aircraft engine manufacturers both past and present. Lycoming continues to this day as an aircraft engine manufacturer. Rolls-Royce Deutschland is a subsidiary of British aircraft engine maker Rolls-Royce plc. In 1938, the French company ceased automobile production and concentrated on aircraft engine production. MTU Aero Engines AG is a German aircraft engine manufacturer.