Green light for green flight : NASAs contributions to environmentally responsible aviation NASAs Environmentally Responsible Aviation (ERA) project began in 2009 to explore and document the feasibility benefits and technical risks of advanced vehicle concepts and enabling technologies for reducing aviations overall impact on the environment. Its goals included reducing community noise footprints fuel burn and nitrogen oxide emissions. This book reviews the advanced aircraft design concepts construction technologies and propulsion advancements that were researched by the ERA project