An Air Force C-17 flew a variety of landing profiles at Edwards Air Force Base as part of a NASA noise mitigation study conducted Sept. 10, 2005.

NASA, the United States Air Force and Northrop Grumman Corp. partnered for the test flights. NASA researchers from Ames Research Center, Moffett Field, Calif., and Dryden Flight Research Center, Edwards, Calif., led the collaborative effort. The C-17 flight experiment was sponsored by the NASA Aeronautics Research Mission Directorate's Vehicle Systems Program (VSP).

Seventeen microphones, covering approximately 15 square miles, were positioned on the dry lakebed to record the noise footprint of the Air Force Flight Test Center's C-17 Globemaster III as it attempted various landing approaches. In addition to conventional straight-in landing profiles, a new type of simultaneous and non-interfering (SNI) landing profile was flown. This new approach is similar to a descending spiral over the landing site.

Research participants, using laptops connected to GPS receivers and equipped with third-generation sound cards, collected data from the flights to validate a modeling tool for predicting SNI approach noise footprints. The flights also tested the hypothesis that employing this landing approach could help keep aircraft noise within the airport land use zone.