The requirement of Unmanned Aerial Aircrafts (UAVs) is attracting R&D institutions to search for efficient alternative energy resources and energy conversion systems. Fuel cell exhibits high second law efficiency and has the capability of converting electrochemically several fuels. Hydrogen is a promising fuel for aircrafts due to exhibit the highest specific energy and carbon free. This fuel is not available in its pure form and industries utilize diverse technologies to extract from other energy resources such as biomass. However, the feasibility of the fuel depends on both efficient extraction and usage in energy conversion systems. Consequently, the entire power chain of converting biomass into mechanical work should be analyzed [1]. This study presents the results of a "Well-to-Wing" efficiency analysis (WTW) of liquid hydrogen produced through biomass gasification for aviation. The power chain comprises 3 subsystems: a biomass gasification plant, a hydrogen liquefaction unit, and a Solid Oxide Fuel Cell/Gas Turbine (SOFC/GT) system. Results reveal that the SOFC/GT system provides considerable higher exergy efficiency when compared to the competing propulsion systems whereas the conventional hydrogen liquefaction process induces significant exergy destruction, generating inefficiency in the entire power chain. Hence, conclusions also provide suggestions for increasing the overall efficiency. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.