This study was performed to identify the risk of contamination of avionics circuit boards from the deposition of dust due to the deployment of aircraft in Southwest Asia (SWA).  A total of seven site visits were made to USAF, Air National Guard and US Army bases over a nine month period in which maintenance personnel were interviewed and aircraft/avionics recently returning from SWA were inspected for evidence of dust contamination.  Chemical analyses of the surfaces of the avionic circuit boards were performed to determine the level of cleanliness as well as to identify the chemical ions present that could lead to accelerated corrosion and failure of the avionics of the aircraft. Results indicate that the overall probability of dust contamination is high for avionic circuit cards for aircraft deployed in SWA. This effort has shown that there is a higher probability of avionic circuit cards in open vented LRUs becoming contaminated with dust than cards located in cold wall cooled or conditioned air cooled LRUs. The probability of avionic cards in cold wall cooled or conditioned air cooled LRUs becoming contaminated is higher for rotor aircraft than for fixed wing aircraft.