Training programs for combat aviators have historically centered around in-flight training. Simulation for the most part has not been able to replicate the dynamic environment encountered during wartime operations. Mission Essential Competencies (MECs) are focused on complex mission-level skills in relation to an operational environment. MECs are broad in nature, but they are not abstract knowledge or general skills. They are demonstrated in the context of an actual or high-fidelity simulated mission, under wartime conditions. Training programs are tied to the conditions under which the performance tasks are finally conducted and evaluated. For combat aviation, the true condition of performance is the combat environment, but for obvious reasons, the US Air Force does not train in actual combat conditions. The MEC process is a unique approach to work analysis in that the knowledge and skills required to do a job are specified at the level of actual mission performance.