Vortex Advisory System Safety Analysis : Volume III, Summary of Laser Data Collection and Analysis

PDFTech ReportDOT-TSC-FAA-79-20-3FAA-RD-78-68-3AirplanesAirport runwaysDoppler effectLaser velocimetersMeasurementStatistical analysisVorticesWakesUnited StatesUnited States. Federal Aviation AdministrationHallock, James N.John A. Volpe National Transportation Systems Center, (U.S.)Federal Aviation AdministrationAGR-SAFETY AND SECURITY-SAFETY AND SECURITYNTL-AVIATION-AVIATIONNTL-AVIATION-Airports and FacilitiesNTL-AVIATION-Air Traffic ControlNTL-AVIATION-Aviation Safety/AirworthinessNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic FlowNTL-OPERATIONS AND TRAFFIC CONTROLS-OPERATIONS AND TRAFFIC CONTROLSVolpe National Transportation Systems Center, Technical Reference CenterA Laser-Doppler velocimeter (LDV) was used to monitor the wake vortices shed by 5300 landing aircraft at a point 10,000 feet from the runway threshold. The data were collected to verify the analysis in Volume I of the safety of decreasing interarrival separations to three nautical miles between the outer marker and the runway threshold. Such reduced spacings would only be used when the Vortex Advisory System (VAS) indicated that wake vortices would not pose a threat to a following aircraft. The data show that vortex behavior, during times identified by the VAS, is commensurate with the goal of using uniform three-nautical-mile separations from the outer marker to touchdown regardless of leader or follower aircraft type