A method and system compares combinations of vehicle or aircraft state variables against known combinations of potentially dangerous states. Alarms and error messages are selectively generated based on such comparisons. In one embodiment, pairs of aircraft state variables are selected and compared to known undesirable pairs of state combinations that indicate an error or a condition that a crew should monitor closely. The combinations and error messages are provided by the database. The comparisons are conducted on a periodic basis monitoring real time states of the parameters collected from various sensors and commands. Experts considering a matrix that provides an exhaustive pairwise comparison of potentially important state variables initially identify undesirable state combinations. Error messages and identification of potential alarms are generated based on both knowledge of actual accidents, and on use of expert knowledge to predict potentially dangerous states.