FAA urges airlines to replace altimeters that can’t filter out 5G signals

Enlarge (credit: Getty Images | BackyardProduction)

The Federal Aviation Administration is reportedly urging airlines to retrofit or replace altimeters that receive transmissions from outside their allotted frequencies. The FAA is meeting Wednesday "with telecom and airline industry officials on a push to retrofit and ultimately replace some airplane radio altimeters that could face interference from C-Band 5G wireless service," Reuters reported Tuesday.

The Reuters report continued:

The FAA wants to use the meeting to establish "an achievable timeframe to retrofit/replace radar altimeters in the US fleet," according to a previously unreported letter from the FAA's top aviation safety official Chris Rocheleau reviewed by Reuters. It also asked aviation representatives "to offer options and commit to actions necessary to meet these objectives."

Some altimeters used by airplanes to measure altitude apparently cannot filter out transmissions from C-Band frequencies assigned to wireless carriers for 5G. Altimeters are supposed to use frequencies from 4.2 GHz to 4.4 GHz, while wireless carriers' C-Band licenses are for 3.7 to 3.98 GHz.