Potential problems to aircraft related to the operation of gas turbine engines in the presence of volcanic ash clouds arose once again last spring with the eruption of the Iceland volcano “Eyjafjallajokull.” Unfortunately, to this point in time relatively little has been done to provide operational guidance for the government or the airline industry. Some action is being taken to help provide “a statement of the-state-of-theart” of what is presently known. This discussion focuses on:

-Potential engine response to such an environment
-Current ability of forecasters to predict dust cloud concentration, movement, and depth of contamination
-How air crews may be able to recognize a contaminant environment more dense than thought
-Appropriate crew action in the event the environment is inadvertently more severe than limits allow