Airborne tactical decision making is degraded as a result of sophisticated threat capabilities, high data rates and uncertainties, and the necessity for timely response. Under investigation at the Naval Air Development Center is the concept of a plan recognition model to assist the tactical decision maker in interpreting and predicting the activities of enemy platforms.* On-going work in the field of plan recognition was surveyed, knowledge acquisition conducted, and a prototype plan recognition model has emerged. The model is a hierarchical, blackboard based adaptation of a more general architecture of cognition. The model attempts to overcome some of the perceived shortfalls of other approaches relative to the complexities of the tactical situation. Extensions to accommodate uncertain events and elusive goals in multi-hypothesis situations are the focus of current activities.