American Institute of Aeronautics and Astronautics
Overcoming the Adoption Barrier to Electric Flight
Nicholas K. Borer1, Craig L. Nickol2, Frank P. Jones3, Richard J. Yasky4, Kurt Woodham5, Jared S. Fell6, Brandon L. Litherland7
NASA Langley Research Center, Hampton, Virginia 23681
Patricia L. Loyselle8, Andrew J. Provenza9, Lee W. Kohlman10 NASA Glenn Research Center, Cleveland, Ohio, 44135
Aamod G. Samuel11 NASA Armstrong Flight Research Center, Edwards, California 93523
Electrically-powered aircraft may enable dramatic increases in efficiency and reliability, reduced emissions, and reduced noise as compared to today’s combustion-powered aircraft. This paper describes a novel flight demonstration concept that will enable the benefits of electric propulsion, while keeping the convenience and utility of common fuels available at today’s airports. A critical gap in airborne electric propulsion research is addressed by accommodating adoption at the integrated aircraft-airport systems level, using a confluence of innovative but proven concepts and technologies in power generation and electricity storage that need to reside only on the airframe. Technical discriminators of this demonstrator include (1) a novel, high-efficiency power system that utilizes advanced solid oxide fuel cells originally developed for ultra-long-endurance aircraft, coupled with (2) a high-efficiency, high-power electric propulsion system selected from mature products to reduce technical risk, assembled into (3) a modern, high-performance demonstration platform to provide useful and compelling data, both for the targeted early adopters and the eventual commercial market. The proposed demonstrator concepts all meet or exceed the program goal of a 50% reduction in mission fuel cost compared to the unmodified aircraft.
I. Introduction The use of electric motors for aircraft propulsion is a topic of increasing interest in the aviation community,
largely due to the significant increase in efficiency of these motors vs. traditional internal combustion engines (ICEs). For light aircraft, these motors are more compact, lighter, quieter, and far more reliable than the reciprocating combustion engines that are currently used for primary propulsion . For larger aircraft, the relatively scale-invariant nature of efficiency vs. power level (and engine size) tends to enable more distributed propulsion architectures than seen with typical thermodynamic cycles used for propulsion [2, 3]. Distributed electric propulsion architectures can yield a net benefit in total efficiency due to synergistic airframe-propulsive coupling .
Ongoing electric aircraft development, research, and eventual production projects are focusing on the low- power, low-range, limited utility platforms dedicated to the flight training market, as seen in the Airbus E-Fan  and the Pipistrel Alpha Electro . These are seen as stepping-stone platforms by their parent companies for
1 Aerospace Engineer, Aeronautics Systems Analysis Branch, MS 442, AIAA Senior Member. 2 Senior Aerospace Engineer, Aeronautics Systems Analysis Branch, MS 442, AIAA Senior Member. 3 Associate Director, Research Services Directorate, MS 255A. 4 Chief Pilot, Operations & Engineering Branch, MS 255A. 5 Computer Research Engineer, Safety Critical Avionics Branch, MS 130. 6 Mechanical Design Engineer, Aeronautics Systems Engineering Branch, MS 238. 7 Pathways Student, Aeronautics Systems Analysis Branch, MS 442. 8 Electrical Engineer, Photovoltaic and Electrochemical Systems Branch, MS 309-1. 9 Aerospace Research Engineer, Multiscale and Multiphysics Modeling Branch, MS 49-8. 10 Research Aerospace Engineer, Rotating and Drive Systems Branch, MS 49-8. 11 Aerospace Engineer, MS 4840D, AIAA Member.
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54th AIAA Aerospace Sciences Meeting 4-8 January 2016, San Diego, California, USA