Aviation Uses: For airline applications, Fluid Film® has been tested by the U.S. Air Force in accordance with Mil-C-16173-E Grade 2, and found to exceed all requirements. Delta Airlines wrote a process standard recommending Fluid Film® as a general purpose maintenance lubricant, stating that "Fluid Film® differs from other general purpose maintenance lubricants in that the lubricating capability remains for extended periods of time and is not subject to evaporation." Studies conducted by Purdue University found Fluid Film® to protect against stress corrosion cracking. When applied prior to exposure of the protected surface to an aggressive environment, Fluid Film® was most effective. Boeing's Space Systems Division wrote a specification for Fluid Film's use on the Space Shuttle after Fluid Film® passed the rigid testing standards for maintenance materials. Film® is the only product to meet the specifications for use on the Space Shuttle. Fluid Film® was also tested by Boeing's Engineering Materials and Process Laboratory and found to be twice as effective as commonly used CPC's for aluminum alloys. Sundstrand Aerospace wrote a specification for Fluid Film's use as a preservative oil for magnesium, which is now used as a standard throughout the helicopter industry. The U.S. Coast Guard wrote an engineering specification for Fluid Film with the purpose being to improve the corrosion resistance of corrosion prone areas of aircraft.