This SAE Aerospace Information Report (AIR) discusses the sources of Copper in aviation jet fuels@ the impact of Copper on thermal stability of jet fuels and the resultant impact on turbine engine performance@ and potential methods for measurement and reduction of the catalytic activity of Copper contamination in jet fuels. This document is an information report and does not provide recommendations or stipulate limits for Copper concentrations in jet fuels. Purpose While Copper alloy containment vessels and plumbing are the exception in shore-based jet fuel storage and transport@ they can be found in naval applications where Copper alloys@ such as Admiralty Brass@ are used. Dissolved Copper in jet fuels is known to stimulate the thermo-oxidative degradation of the hydrocarbon species in jet fuels. Thus@ the removal of Copper from jet fuel is critical to maintaining fuel properties and fuel system performance in turbine engines. The purpose of this document is to summarize available information on Copper contamination in jet fuels@ the impact of Copper on jet fuel thermal stability@ methods for measurement of Copper in jet fuels@ and potential methods for reduction of the catalytic activity of Copper contamination in jet fuels. The information in this AIR is not intended as a specification for Copper concentration in jet fuels or recommendation/acknowledgement for the use of Copper in aircraft/engine fuel systems.