Aggressive Emissions Targets Drive Aeronautical Research

Airline industry’s commitment to reverse emissions growth depends on successful research outcomes

Printed headline: Key Developments

Tough environmental targets are driving research into future commercial airliners on both sides of the Atlantic, but if new aircraft configurations are required to meet the aggressive goals, they could take decades to develop and deploy. Airlines, through the International Air Transport Assn., have committed to improve fuel efficiency 1.5% a year through this decade; to achieve carbon-neutral growth from 2020; and to halve carbon emissions by 2050 relative to 2005 levels. Those targets are anchored in assumptions that European and U.S. research programs will deliver promised reductions in fuel burn and emissions as well as airport noise. In Europe, the seven-year, €1.6-billion ($2.3-billion) Clean Sky joint-technology initiative is aiming for 30% reductions in carbon dioxide and nitrogen oxide emissions by 2020. In the U.S., NASA’s five-year, $320-million Environmentally Responsible Aviation (ERA) program is focused on large airliners entering development around 2020, and is aiming for reductions of 40% in fuel burn, 75% in landing and takeoff NOx and 42dB. in noise relative to Stage 4. NASA believes the blended wing-body configuration has the greatest potential to reduce emissions.Credit: ROYAL AERONAUTICAL SOCIETY/KAKTUS DIGITAL Two Clean Sky projects most closely aligned with airline needs are the €393-million Smart Fixed Wing Aircraft (SFWA) and €117-million Green Regional Aircraft (GRA) integrated technology demonstrations. Led by Airbus and Saab, SFWA aims to fly a smart wing with passive and active laminar flow and load control and to demonstrate propulsion/empennage integration with open-rotor engines. Led by Alenia Aeronautica and EADS CASA, GRA is aiming for a 40% reduction in regional-aircraft CO2 and NOx emissions by 2020 through reductions in weight, drag and fuel burn. Technologies to be demonstrated include advanced lightweight structures with embedded damage sensors, all-electric systems, and low-noise high-lift devices and landing gear. Launched at the end of 2009, the ERA program brings together NASA’s ongoing work on laminar flow, open-rotor and ultra-high-bypass engines, low-NOx combustors and advanced configurations. So far, the hybrid or blended wing-body (BWB) aircraft has been the main focus, but under ERA NASA will also look at other configurations with the potential to meet environmental targets. While Europe intends to fly several large-scale demonstrators under Clean Sky, NASA’s plans are limited to ground tests, although additional flights of the X-48 subscale unmanned BWB demonstrator could be conducted to evaluate noise-shielding benefits. If additional funding is secured, the agency would like to fly a large-scale X-plane demonstrator combining the aerodynamic, structural and propulsion technologies being matured under the ERA program.