Wildland firefighting is an inherently dangerous activity, and aviation-related accidents in particular comprise a large share of firefighter fatalities. Due to limited understanding of operational factors that lead to aviation accidents, it is unclear how local decisionmakers, responsible for requesting aviation support, can mitigate the risk of an aviation accident once resources are requested. This research expands the knowledge base regarding the quantification and analysis of aerial firefighting exposure by developing methods to evaluate expected aviation accident rates at the incident level using a metric called the aviation exposure index (AEI). Our analysis is based on coupling historical aviation accident rates (10-year average) with observed aviation resource use. As an example of the applicability of the approach, we present results according to aircraft type, unique incident, and incident jurisdiction for large wildfires that occurred during the 2012 US fire season. Ideally, the AEI could be automatically calculated and incorporated into incident decision support systems to help guide fire managers as they balance the complicated tradeoffs between attaining wildfire management objectives and reducing the exposure of individuals engaged in aerial firefighting activities.