Soot Emissions from Jet Aircraft

Description of the Tests The emission of particles from jet engine exhaust into the atmosphere is a serious environmental concern. When particles are emitted into the atmosphere they can absorb water and NOx from the jet exhaust. In the troposphere these particles can become condensation nuclei and increase the propensity for cloud formation. In the stratosphere the nuclei can become catalysts for ozone depletion. Regulating agencies are becoming more cognizant of the role of engine exhaust in the environment and are in the process of establishing regulations for military and civilian aircraft. The characterization of particles emanating from jet exhaust is considered by NASA to be of primary importance in environmental studies of the High Speed Civil Transport (HSCT). In order to assess the impact of the proposed supersonic and the operational subsonic fleets on the environment, experimental studies must be carried out to determine the impact of various emissions. McDonnell Douglas has formed a team with the Cloud and Aerosol Sciences Laboratory at the University of Missouri at Rolla to conduct such studies. We are currently making particulate measurements in the McDonnell Douglas hush houses on the GE 404 engines in order to improve our techniques for making ground level tests. This paper presents the results from these ground test measurements, contrasts these with those of flight tests and discusses their impact on proposed environmental inventories of soot