Juneau and Palm Springs might seem worlds apart but they're both a lot easier to get to thanks to a GPS-based instrument landing system developed by Alaska Airlines and approved by the FAA. The Required Navigation Performance (RNP) system uses on-board transmitters and GPS signals to allow pilots much lower minimums when landing at airports with narrow approaches surrounded by mountains. The system was first put into use at several Alaska airports with their notoriously poor weather. But clear, dry, CAVU Palm Springs? Apparently not always. Earlier this month, low valley cloud accompanying a rainstorm (!) at Palm Springs caused Alaska to cancel, delay or divert 24 flights. Other airlines were similarly affected, including Calgary-based WestJet's maiden run to Palm Springs. The winter-weary Canadians ended up at LAX instead. When the weather is down at ILS-less Palm Springs, the new system allows Alaska flights to operate to 250 feet and three-quarters of a mile.