Economic and Environmental Assessment of Hybrid-Electric Commuter Aircraft: A Business Case for the Spanish Seaplane Market

the Valencia–Palma de Mallorca route and compares its performance with a conventional Twin Otter–class aircraft. A Total Cost of Ownership framework is applied, combining mission-based energy modeling with detailed estimates of Direct Operating Costs (DOC), capital expenses, and battery replacement requirements. A 15-year financial analysis evaluates Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period. Results show that hybrid-electric propulsion significantly reduces fuel use and CO2 emissions but introduces higher ownership costs and additional maintenance items, yielding a DOC comparable to the conventional configuration. Despite higher revenue potential, the hybridelectric design exhibits lower NPV and IRR due to increased capital intensity. Sensitivity analyses indicate strong improvements under reduced battery costs, higher kerosene prices, or policy incentives for low-emission aircraft. Overall, hybrid-electric seaplanes demonstrate promising long-term potential, contingent on technological maturation and supportive regulatory frameworks.