The F-22 program office is seeking to better characterize the impacts of clear water rinsing and handwashing in different operational conditions. The Naval Research Laboratory's testing facility in Key West, FL was chosen to test multiple, modified conditions against the same ambient environment. The effect of select environmental parameters on the atmospheric corrosion of silver and steel was assessed. The effect of clear water rinsing (consistent with current preventative maintenance strategies) was evaluated by rinsing all samples with fresh water thrice/twice a week, once a week, or naught at all. The effect of covering was tested by sheltering a set of samples underneath a canvas shelter, consistent with aircraft covering currently used. The effect of natural seawater spray was tested on select samples by spraying them either once a day or twice a day. All conditions were compared against the ambient exposure condition of Key West. The steel mass loss was compared across all conditions. The accumulation of silver compounds was assessed with galvanostatic reduction. The role each parameter plays in the corrosion process is discussed. Specifically, findings will be used to quantify the short-term impacts from accelerated outdoor testing. This effort will serve to better inform aircraft maintenance.


Aerospace assets are subjected to routine maintenance cycles to prevent, monitor, and repair corrosion damage. Currently, the maintenance cycles are determined according to its model and following its respective requirements document (eg: NA(1) 01-1A-5091 or USAF(2) Technical Order 1-1-691).2 A new paradigm of condition-based maintenance (CBM) is highly desired, as a given asset will require different prevention, monitoring, and repair maintenance cycles depending on where it is deployed. As corrosion is the degradation of a material in response to its environment, CBM takes into consideration the variability of the environment (the conditions to which an asset is exposed) when determining appropriate maintenance intervals and what should be done at each interval. Implicit in this, is the desire to alter the effective environment to more favorably alter the requirements for maintenance. Strategies include clear water rinsing (CWR), sheltering/covering assets, wash practices, and maintenance "personalization" based on unique asset and environment combinations.

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