Cost-Effective Design and Operations of Regional Hybrid-Electric Aircraft

Abstract

The economic case for hybrid-electric aircraft is often assessed on a single design mission, with less attention to airline network constraints and battery ageing. This paper presents a feedforward framework coupling conceptual aircraft sizing with a mixed-integer linear programming (MILP) tail-routing model that embeds battery degradation directly in the fleet operatingcost objective. Hybrid-electric variants of a regional turboprop (design ranges 600 to 1400 km, hybridisation 0 to 30%) are evaluated across two European networks and three economic scenarios. Under the reference cost assumptions, hybridising the reference aircraft raises cost per available seat kilometre (CASK) by about 17%, driven by utilisation, since charging lengthens turnarounds and requires an extra aircraft to serve the same demand. Modelling battery degradation changes the charging strategy: a fixed-coefficient degradation formulation selects schedules whose audited battery cost is 75% higher than self-assessed, yet the choice between plausible ageing scenarios reprices operations by only ±2%. Range margin, nearly free conventionally, costs up to 26% of CASK at high hybridisation, and under high fuel prices the cost-minimising design decouples from the minimum-weight design by 4 to 6%. Network operations and battery ageing can be first-order inputs to regional hybrid-electric aircraft design.