Problems at PDX

Got this release this around 11 pm Saturday night from Oregon’s Portland International Airport. I’m not sure what they mean: “the removal of a key navigational aid…?”  Is it out for service? Stolen?

PDX Arrivals Currently Being Diverted

Due to a combination of weather conditions and the removal of a key navigational aid used to assist pilots in low visibility, between 20-30 flights destined for Portland are being diverted to other airports. Some passengers are returning to Portland via bus this evening.

Due to anomalies in the runway navigational aid, flights were diverted in the best interest of safety. The FAA will inspect the system tomorrow morning and with the go ahead, runways will resume normal operations. All passengers and those expecting to greet arrivals are encouraged to check their flight status before leaving for the airport.