This SAE Aerospace Recommended Practice (ARP) is intended to evaluate corrosion inhibiting properties of synthetic gas turbine lubricants and gearbox oils. This ARP is a modified form of a method developed in the United Kingdom as DERD Test Method/ 1@ Method No. 18@ Issue 1 of January 1984. (Reference 2.1.) Field of Application: Primarily to evaluate corrosion inhibiting properties of aircraft engines@ gearboxes and propulsion system lubricants.