Risk study needed before FAA ditches direction finders

April 2, 2008

Risk study needed before FAA ditches direction finders

By AOPA ePublishing staff

GPS, ADS-B, and advanced radar services have improved aviation safety, but the FAA should ensure that they are adequate substitutes for tried-and-true direction finders (DF).

That’s the message AOPA sent the FAA in formal comments filed March 28 in response to the agency’s plan to decommission the remaining 22 DF sites in Alaska.

In its comments, AOPA asked the FAA to conduct a safety risk study before making a final decision about the fate of DF in Alaska. The agency conducted a similar study before it decommissioned other U.S. DF sites in 2007. But because of Alaska’s rugged terrain, challenging weather, and enormous size, DF may still serve an important safety function, AOPA warned.

“Pilots flying at low altitudes have limited radar coverage and new ADS-B technology is still several years from full implementation,” explained Melissa Rudinger, AOPA vice president of regulatory affairs. “We need a study to determine whether these newer technologies can provide an equivalent level of service and safety without DF in the mix.”

DF is used to help lost pilots get back on course by homing in on the aircraft’s radio transmissions and providing a bearing to the aircraft’s radio. One station can pinpoint the pilot’s position by having the aircraft make turns and assessing the bearing change. If two DF stations are in range, the bearings can be plotted on a chart.

April 2, 2008