By Mary Grady, Contributing editor
The FAA has asked for comments on its plan to take the last Direction Finders in U.S. airspace offline. Twenty-nine DFs remain operational in Alaska, along with their associated approaches, but the FAA says nobody has used them since 2008. GPS and ADS-B have reduced the need for DF steers, the FAA says, and Flight Service Stations have other tools available to assist lost or disoriented pilots, such as VOR, ADF, and GPS. "DF equipment is beyond its useful lifecycle," the FAA says. If you disagree, or have any opinion on the matter, the FAA is ready to hear your comments until Sept. 10.
DF sites outside Alaska were shut down in 2007, and AOPA said it doesn't oppose the plan to shut down the remaining facilities. However, AOPA asked the FAA to apply whatever money it saves to expand ADS-B coverage in Alaska. DF is used to help lost pilots get back on course even if they have no navigation gear other than a radio. The system detects the aircraft's radio transmissions and provides a bearing to the aircraft, AOPA said. One station can pinpoint the aircraft's position by having the pilot make turns, then assessing the bearing change. If two DF stations are in range, the bearings can be plotted on a chart. The complete FAA notice, with information about how to submit comments, is posted online.