The breakdown or failure of crew resource management (CRM) has been cited as a causal factor in a large number of civilian and military aviation accidents. However, a recent review of the literature has revealed that many of the CRM concepts currently being trained are unrelated and/or unclear, making it difficult to determine the effectiveness of existing CRM training programs. The U.S. Navy/Marine Corps are no different. In an effort to determine the critical skills that should be taught, we examined U.S. Navy/Marine Corps Class A aviation accident data between 1990 and 2000 for CRM failures. In this study, 275 U.S. Naval aviation CRM failures were examined to identify those critical to safety in U.S. Naval aviation. Of the six CRM failures identified, the failure to conduct an adequate brief and the lack of communication accounted for over 50% of the failures examined, suggesting the importance of these areas when training CRM.