Project boundary and airport data are derived from the VATSIM VAT-Spy Data Project, https://github.com/vatsimnetwork/vatspy-data-project, CC BY-SA 4.0. The project data have been filtered to the current Specialist areas. See VATSPY-LICENSE.txt for the full license. The 25 NM airport rings are illustrative and do not represent official approach boundaries. Basemap: OpenStreetMap contributors, https://www.openstreetmap.org/copyright. Map library: Leaflet, https://leafletjs.com/.