The readiness of military defense radar is absolute in effort to maintain Indonesia air sovereignty from potential threats that may enter and endanger the security of citizens and residents throughout Indonesia territory. Currently, the radar health condition monitoring system has not been integrated in a whole system integrated manner between the subsystems each other, it causes a relatively long time to identify critical failures that may arise in the related subsystems. Prognostics and health management (PHM) takes the current state of the system as a starting point, combined with structural characteristics, parameters, environmental conditions, and historical data of objects, to monitor the equipment working status with various knowledge, algorithms, and models based on advances in sensor acquisition technology. PHM on MASTER-T radar maintenance is proposed using the method of failure mode effect and criticality analysis (FMECA) which aims to predict critical failures, thus preventing fatal damage that can result in system breakdown. Predictive maintenance is added to conventional maintenance, thereby minimizing idle time when repairs must be made with the radar system inactive. The application of this method obtains a risk priority number (RPN) which is used as a reference in determining critical components that must be repaired immediately.