In the research, a FRAM model for the engine maintenance process was obtained and its potential variability was identified. Based on this information, possible unwanted results in the maintenance process from the occurrence of functional resonances within the model were analyzed, allowing us to present proposals to control the consequences of uncontrolled variability that were found during the research. The results demonstrate the potential of the use of FRAM in aeronautical maintenance, as the methodology facilitated the elaboration of a valuable analysis of the accomplished process within Army Aviation, with the potential to be applied in other aviation engine maintenance centers.