The Department of Defense will conduct a series of radar data collection flights over the National Capital Region (NCR) from June 21-23 in coordination and cooperation with the Federal Aviation Administration (FAA).
The following aircraft will be involved in low altitude flights: a Dassault Falcon 20 jet; a BD-5J turbojet; a DeHavilland DH6 twin engine turboprop airplane; and an Inventus radio controlled aircraft.
The purpose of these flights is to allow ground-based sensors in and around the NCR to exercise their ability to obtain/detect radar signatures from aerial vehicles of varied sizes and operating characteristics.
Citizens throughout the region may hear aircraft noise during daytime hours and observe these aircraft as they fly routes within the NCR. The impact of these flights will be relatively minor to commercial aircraft, and all flights will be conducted in accordance with FAA standards.
http://defenselink.mil/advisories/2006/pa20060620-13304.html