SEATTLE, WASHINGTONOn Monday, Alaska Airlines' regional subsidiary Horizon Air suspended all flights in and out of the Paine Field to avoid 5G interference, as fog shrouded the airport.

Because the 5G transmissions could interfere with aircraft altimeters, some types of planes are not allowed yet to conduct instrument approach procedures (IAP) for airports near 5G antennas and towers.

Alaska's Horizon Air is currently the only airline operating commercial flights out of Paine Field with the carrier's Embraer E175 regional jets.

FAA imposed limitations for some airports near 5G stations such as Paine Field and Portland International Airport to prevent interference with airplanes' avionic systems.

A dozen of inbound flights and a dozen of outbound flights of Horizon Air were canceled on Monday at Paine Field due to the 5G interference risk since pilots were completely dependent on cockpit instruments data during landing due to the low-visibility conditions around the airport.

The American mobile service providers Verizon and AT&T activated their 5G services last week across the country, which could interfere with aircraft's altimeters that are used to precisely measure the flight level above the ground.

The U.S. Federal Aviation Administration works on an airplane-by-airplane and airport-by-airport analysis to determine aircraft types that will be allowed to fly in low visibility conditions in a 5G environment. The agency has so far cleared all Boeing and Airbus types for conducting Instrument Approach Procedures (IAP) at most airports around the country.

The Embraer E175 jets were excluded entirely from low-visibility flying at both Paine Field and Portland International.

The restrictions involve not just Horizon Air, but carriers like SkyWest that operate local regional flights with 76-seat E175 jets.