Associate Editor, AIAA Journal of Propulsion and Power, 1996-99
AIAA Associate Fellow, Chair of Turbine Engine Committee 1996-98, AIAA Air-Breathing Propulsion Technical Committee 1995-1999
Member ASME Turbomachinery Committee
Member American Society of Engineering Education
Lead Author, United Nations Environment Programme, Intergovernmental Panel on Climate Change, Special Report on Aviation and the Global Atmosphere, 1999
Defense Sciences Study Group, Class of 2000-2001
Joint Strike Fighter Independent Technical Review Team for Air Quality and Noise, 2000
NRC Committee on Aeronautics Research and Technology for Environmental Compatibility, 2000-2001
NASA Aircraft Engine Emissions Characterization and Inventory Committee, 2001-2003
NASA Quiet aircraft Technology Technical Working Group, 2001-2003
Duke University Mechanical Engineering Undergraduate Advisory Board, 2001-present
Defense Science Board Task Force on B-52 Re-Engining, 2002
Member of U.S. Delegation to ICAO Committee on Aviation and Environment/6 (as an advisor), 2004
FAA National Particulate Roadmap, Impacts Team lead, 2004-present
Director of Partnership for AiR Transportation Noise and Emissions Reduction (PARTNER), an FAA/NASA/Transport Canada-sponsored Center of Excellence, 2004-present
Director, Congressional Study on Long-Term Environmental Improvements, 2004-2005
NRC Committee to Assess the Integrated Plan for a Next Generation Air Transportation System (JPDO), 2004-2005
National Academy of Engineering, Steering Committee for the Technology for a Quieter America Study, Chair of Cost-Benefit Analysis Subcommittee, 2006-present
Transportation Research Board/National Academy of Sciences, Study on Transportation and Greenhouse Gas Reduction, Committee member, 2007-present