RELIABILITY MODELING OF HYBRID ELECTRIC AIRCRAFT PROPULSION SYSTEMS UNDER PARTIAL POWER LOSS CONDITIONS

Abstract

The aviation industry's transition toward hybrid electric propulsion systems represents a significant shift in aircraft design philosophy, introducing new reliability challenges that differ fundamentally from traditional turbine-based systems. This research develops comprehensive reliability models specifically addressing partial power loss scenarios in hybrid electric aircraft propulsion architectures. Unlike conventional all-or-nothing failure modes, hybrid systems can experience degraded states where portions of the propulsion network remain operational while others fail. Understanding these partial failure conditions is critical for ensuring aviation safety standards while enabling efficient hybrid designs. Our modeling framework incorporates component-level failure rates, system architecture redundancies, and degraded operational modes to predict overall propulsion reliability under various failure scenarios. The research examines series, parallel, and series-parallel hybrid configurations, analyzing how architectural choices impact fault tolerance and continued operation capabilities. Through Monte Carlo simulation and fault tree analysis, we quantify reliability metrics including mean time between failures, probability of catastrophic power loss, and expected degraded operation durations. Results demonstrate that thoughtfully designed hybrid architectures can achieve reliability levels exceeding traditional propulsion while providing graceful degradation capabilities. This work provides aerospace engineers with quantitative tools for reliability-informed design of next-generation hybrid electric aircraft, contributing to both safety assurance and certification processes.