Despite short-term fluctuations, the most conservative projections of long-term growth for commercial aviation indicate that, without significant technological advances, the environmental impact of aviation will begin to grow again after decades of continuous reductions. Emissions at ground-level and in the air (such as carbon dioxide, nitrogen oxides, water vapor, particulate matter, and unburned hydrocarbons), engine and airframe noise, and the creation of contrails and cirrus clouds contribute significantly to the environmental footprint of commercial aviation and to global warming and climate change.
Enabling growth with decreased environmental impact will require innovative ideas in a variety of areas. We will need a better understanding of the physics (acoustics, atmospheric chemistry, combustion, global climate impact), advanced aircraft configurations with radically improved fuel-burn and vastly reduced noise and emissions, advanced air-traffic management approaches, and alternative fuels. This will require a multidisciplinary research effort that, in addition to a number of well known approaches, can draw from creative ideas, such as flying airplanes in formation, altering significantly the overall configuration of the aircraft (such as by using blended wing bodies or truss-braced wings or by flying slower at different altitudes), and devising aircraft component technologies to reduce noise and emissions.
The Aeronautics and Astronautics Department is well situated to tackle many of these challenges. Through the combined efforts of the Aerospace Design Lab, the Aircraft Aerodynamics and Design Group, the GPS Lab, and the Unsteady Flow Physics and Aeroacoustics Laboratory, and collaborations with other departments, the Aero/Astro Department is tackling many of the key enabling technologies and ideas to make a sustainable commercial aviation system a reality.