Extended Abstract (492K)2.7
Case studies of selected Runway Visual Range (RVR) events at three major USA airports
David A. Hazen, Titan/System Resources Corporation, Billerica, MA; and T. A. Seliga, L. G. Jacobs, and P. Narvett
The USDOT Volpe Center has monitored the operational performance of new RVR systems at several major US airports for several years. In this paper, a number of RVR impaired visibility events are analyzed at three of these airports: Denver International Airport, Denver, CO (DEN); Portland International Airport, Portland, OR (PDX); and O'Hare International Airport, Chicago, IL (ORD). PDX is located adjacent to the Columbia River, not very far from the Pacific Ocean. ORD is inland, but west of and near Lake Michigan. DEN is well inland and about 1.6 km above sea level. DEN covers the most land area of the three airports and has the longest runways. PDX has six visibility sensors (VS) serving three runways; ORD has 12 VS for seven runways and DEN has 13 VSs for five runways.
The cases selected for analysis here occurred in January 1999; this month corresponded to the highest reported frequency of Category II and III events at PDX and ORD as deduced from previous studies. The results illustrate the behavior of RVR events through examination of extinction coefficients measured with the RVR sensors. Parameters of interest include: duration, spatial homogeneity and movement across the airport domains. Events were classified as fog or snow from official surface weather observations at each site. The RVR characterizations appear to be related to geographic differences among the airports as well as to other factors such as time of day and mesoscale meteorological conditions. The RVR events differed considerably from each other. For example, one snow event started almost simultaneously across an airport whereas another fog event at a different airport began at one region of the airport and then expanded to encompass the entire airport in Category III conditions for a prolonged period of time. Effects of local geography are apparent. For instance, the proximity of PDX to the Columbia River and the Pacific Ocean affects fog generation, characterized by extensive areal coverage and migration of RVR events that follow the river valley in consort with forcing meteorological conditions. Fog events at PDX are also more uniform or homogeneous compared to fog events at DEN and ORD, which tend to be more patchy or inhomogeneous. Operational impacts of different RVR events are postulated.
Session 2, Aviation Weather Case Studies/Accident Reviews
Monday, 13 May 2002, 1:15 PM-2:45 PM
Previous paper