PURPOSE AND SCOPE:

This Aerospace Information Report (AIR) describes a Limited Engine Monitoring System that can be used by the flight crew or the maintenance staff, or both, to monitor the health of gas turbine engines in aircraft. This Air considers monitoring of gas path performance and mechanical parameters, and systems such as low cycle fatigue counters and engine history recorders. It also considers typical measurement system accuracies and their impact. This AIR is intended as a technical guide, It is not intended to be used as a legal document or standard. AIR 1873 supplements ARP 1587, Aircraft Gas Turbine Engine Monitoring System Guide.