Análisis de fiabilidad de sistemas críticos en el A320/A321 y su impacto en el mantenimiento aeronáutico

This work analyses the reliability and maintenance management of critical systems in the Airbus A320/A321 aircraft family through a real-world case study. The main event corresponds to the hydraulic system (ATA 29), specifically the Y RSVR LO LVL warning, observed during line operation and managed following approved maintenance procedures. Based on anonymised maintenance records (techlogs, MOC reports, repetitive defects), the full process is reconstructed from fault detection to rectification, including the application of MEL and AMM references. Reliability indicators and operational impacts derived from MEL limitations and pre-flight checks are assessed. A complementary case from the flight control system (ATA 22, FAC 1 FAULT) is briefly discussed to highlight different failure modes and maintenance strategies within the same aircraft family. Results emphasise the importance of integrating operational data into reliability-centred and predictive maintenance programmes, consistent with EASA Part-M.