FAA issues safety alert regarding new 5G band

U.S. regulators are warning aviators that a new band of 5G mobile phone service might interfere with key safety devices on aircraft.

The Federal Aviation Administration this week issued a Special Airworthiness Information Bulletin warning that “action might be required to address potential interference with sensitive aircraft electronics.”

The 5G spectrum abuts radio signals used by so-called radar altimeters, which measure how close an aircraft is to the ground.

While FAA took pains to say it is working with the Federal Communications Commission and other agencies to allow the new technology to safely coexist with aviation, the safety alert creates an unusual situation in which one agency raises concerns while another has granted its approval. It also illustrates growing frustration within the aviation industry.

Canada recently imposed restrictions on locating new 5G cell towers near the runways of large airports.

Australia, France and other nations have taken steps to limit the chances of aircraft interference.

Radar altimeters are used on planes and helicopters for multiple critical safety functions, including landing when visibility is low, anti-collision warnings and systems that warn pilots when they inadvertently get too low.

Some commercial helicopter flights can’t operate without a working radar altimeter.

The FAA bulletin said pilots should remind passengers to place any 5G device into airplane mode or switch them off during flight, and to notify the agency of any signs of interference.

The new 5G spectrum, called C-Band, can become operational on Dec. 5. The FCC awarded wireless network providers access to the radio bands in a February auction.