FAA issues limits on flight operations to cut risks from 5G

U.S. aviation regulators say they’ve made progress reducing the risk of flight disruptions from new 5G service that’s set to start Jan. 19, but at the same time they’ve issued almost 1,500 orders limiting flight operations across the country.

The Federal Aviation Administration expects to provide information soon on what percentage of aircraft will be subject to the restrictions, the agency said in an emailed statement Wednesday night. It began releasing so-called notices to air missions, or Notams, spelling out new prohibitions on Thursday.

The FAA “has made progress to safely reduce the risk of delays and cancellations as wireless companies share more data and manufacturer altimeter testing results arrive,” the agency said in the release.

AT&T and Verizon Communications reached a compromise with U.S. officials last week, agreeing to delay their 5G service for two weeks and to limit placement of cell towers near 50 airports for at least six months. While the companies have said their new service poses no risk to aviation, the FAA and aerospace-industry groups say tests show devices that calculate altitude could become unreliable if aircraft get too close to cell towers.

Even with the last-minute agreement, the FAA has warned that the risks the new, faster phone service will interfere with aircraft equipment requires them to enact limitations until it can be assured that operations will be safe.

Starting at midnight, the FAA began publishing one of the most sweeping set of Notams in its history, a total of 1,462 orders applying to dozens of large airports as well as vast areas where 5G signals are expected.

Planes landing at Chicago’s O’Hare International, for example, would be prohibited from using certain low-visibility instrument landing procedures unless aircraft manufacturers could show their equipment was safe. O’Hare is among the 50 airports with restrictions on 5G towers, but the notice shows the FAA was concerned interference was still possible.

Many of the notices would restrict certain helicopter operations. Instrument approaches — used when visibility is low — to the Mayo Clinic’s St. Mary’s Hospital in Rochester, Minn., would be barred, for example.

The FAA said Wednesday that in at least some cases, the restrictions would be less than it had anticipated in a directive issued last month.

One type of GPS-assisted landing that it had earlier warned might no longer be permitted will be possible at certain airports, the FAA said.

After studying detailed information about where the wireless companies expect to place 5G towers, the FAA also determined that landings will be permitted without restrictions at some airports. The agency said it may have to enact limits at those airports as 5G is deployed more widely.

The broad impacts on airlines, helicopters and private jets remain unclear. If aircraft manufacturers can show that devices known as radar altimeters are shielded from the new 5G signals, they may face no restrictions, the FAA said.

Manufacturers can apply for what is known as an “alternative means of compliance” that could allow exemptions to some or all of the FAA’s restrictions. The FAA must approve each such application individually.

Companies have begun making such applications, but so far the FAA hasn’t approved any.