OPERATIONAL IMPACTS OF ENGINE REMOVAL AND REPLACEMENT ON KEY PERFORMANCE INDICATORS IN AL-31FP ENGINES OF THE SUKHOI SU-30MKM

Abstract

The Sukhoi Su-30MKM, a high-performance fighter jet utilized by the Royal Malaysian Air Force (RMAF), relies on two AL-31FP engines for its mission-critical operations. One of the primary threats to these engines during flight is bird strikes, which can inflict severe damage on key components such as the rotor blades, leading to engine deficiencies or, in some cases, complete failure. This study documents the systematic process of removing and installing an AL-31FP engine after a bird strike compromised its performance. The engine replacement was executed in full compliance with the Aircraft Maintenance Manual (AMM) and RMAF protocols, ensuring procedural accuracy, safety, and efficiency. The process encompassed several key phases: preparation, tool selection, damage assessment via endoscopy, and post-replacement performance testing. Three key performance indicators were monitored: lowpressure rotor speed (N1), high-pressure rotor speed (N2), and maximum vibration level (VIBmax). Post-installation performance data showed a marked improvement in key engine parameters, with N1 increasing from 76.4% to 92.5%, and N2 from 79% to 92%, both now operating within the designated tolerance limits. Additionally, VIBmax decreased significantly from 70.21 mm/sec to 30.12 mm/sec, well within the acceptable safety threshold of 50 mm/sec. This study, focused on training mode, highlights the importance of structured maintenance practices and precise parameter monitoring in restoring engine functionality and ensuring operational readiness, providing valuable insights for aviation maintenance in military contexts.