The US Air Force is developing a multifaceted approach to assessing knowledge and measuring mission effectiveness and performance in military training and rehearsal environments. This paper will present recent results from a field study using new knowledge assessment technology - the Air Superiority Knowledge Assessment System (ASKAS). ASKAS is a system that has been developed to enable measurement of a pilot's mastery of Mission Essential Competencies (MECs^SM). The pilots watch a series of mission oriented combat engagements which are actual air combat scenarios recorded from simulators, including audio communication between the pilots and the controller. After approximately two minutes of playback, the engagement stops, and the pilot is asked a series of questions. The questions are presented first, followed by the responses, allowing response times to be measured. The questions assess the pilot's knowledge about the events of the preceding vignette, specifically addressing the MECs^SM that are necessary for a successful mission. This process is repeated until the end of the engagement. The paper will present recent results, which include both percent correct and reaction time as a measure of the pilot's situational knowledge and mastery of the MECs^SM. Individual scores are compared to other pilot scores with different amounts of experience; more experienced pilots should have higher scores. We will discuss operational implementation challenges with ASKAS, the assessment protocol developed for field use, and possible future uses for this tool. For example, if a pilot takes the test before and after training events such as Distributed Mission Operations (DMO), training effectiveness can be measured, and will be indicated by higher scores after training. This knowledge assessment system could also be used to pinpoint a pilot's knowledge gaps and outline areas that may need more attention in training.