Advances in aircraft hydraulic systems: Trends and future perspectives.

Hydraulic systems have long been essential components of aircraft operations, providing the power density, reliability, and precision required for flight-critical functions, such as flight control surfaces, landing gear, steering, braking, and thrust reversers. Although hydraulic systems remain essential in aviation, their design and integration are rapidly evolving in response to the requirements of efficiency, sustainability, and safety. Traditional methods such as FHA, FMEA, and ETA are limited, necessitating the use of tools that can analyze
systems that evolve over time. Aerospace systems are constantly evolving into digital, autonomous, and dynamic systems. Therefore, Markov analysis was proposed, which is used when failure sequences matter (order-dependent behavior), recovery, reconfiguration, or latent states exist, and simple fault trees are insufficient. To validate the Markov analysis, a Monte Carlo simulation of the reliability of the aircraft EHA was performed.