New System Will Cut Delays at Colorado Ski Airports

 - September 24, 2009, 11:42 AM

Corporate operators heading for Colorado’s Craig, Steamboat Springs, Hayden and Rifle Airports this winter shouldn’t worry about diverting to Denver and having their passengers complete the trip by car. That’s because the Colorado DOT has purchased and installed a $5.7 million Sensis multilateration system to track aircraft accurately well below the mountain-affected line of sight of distant FAA secondary surveillance radars (SSR). Under the SSR environment, this meant a “one out, one in” approach sequence, with lengthy “procedural” in-trail separations and a daily average of 75 delays during winter. Five miles in-trail separation is now expected with the new system. Multilateration uses groups of unmanned stations–in this case, eight around Rifle and 12 around Hayden–that triangulate aircraft transponder replies to radar-like interrogations from one station in each group. Airport controllers then track all aircraft with accuracy comparable to that of radar and the future ADS-B-Out, but without the latter’s cost. Colorado’s DOT anticipates future multilateration installations covering Alamosa, Aspen, Cortez, Durango, Gunnison, Montrose and Telluride, with all stations operated and maintained by the FAA.