How is engine health monitored during operation and what parameters are tracked?

Engine Health Monitoring (EHM) tracks: Gas path parameters (EGT, fuel flow, spool speeds, pressures) for performance trends indicating deterioration or faults; Mechanical parameters (vibration, oil temperature/pressure/debris) for bearing and gear health; and Life tracking (cycles, hot time) for component replacement scheduling. Analysis methods: Trend monitoring detecting gradual changes, Event detection for sudden shifts, Gas path analysis algorithms determining component efficiency changes, and Vibration signature analysis. Modern engines transmit data in-flight (ACARS, satellite) for ground analysis. Health monitoring enables condition-based maintenance, reducing unscheduled removals by 30-50%.