"Initial test flights are planned for the week of June 27, with up to 14 science flights starting as early as July 1. The P-3B, a four-engine turboprop, will carry nine instruments. The two-engine UC-12 will carry two instruments. Sampling will focus on an area extending from Beltsville, Md., to the northeastern corner of Maryland in a pattern that follows major roadway traffic corridors. The flight path passes over six ground measurement sites operated by the Maryland Department of the Environment."
NASA overflights postponed, Baltimore Sun
"NASA's plans to send low-flying aircraft over the Baltimore-Washington area to measure air pollution levels have been postponed to allow more time to increase public awareness of the flights."