Six flights departing or arriving at Paine Field were canceled Tuesday morning, as foggy weather and new 5G restrictions continued to wreak havoc on the airport’s operation.
All 24 commercial flights out of the small Everett airport were canceled on Monday. On Tuesday morning, the problem persisted. In the afternoon, the weather lifted and visibility improved enough to allow flights to resume.
Alaska Air, whose regional carrier Horizon Air is the only commercial airline operating out of Paine Field, warned that cancellations could continue for several days and was offering some accommodations to affected travelers.
The carrier said it has now canceled a total of 41 flights since the Federal Aviation Administration imposed 5G-related restrictions last week.
“Due to continued fog, a replacement flight from Everett may not be available for the next 2-3 days,” Alaska wrote.
Ticket-holders can reschedule their flights for later this week at no additional cost, or try to reschedule their trips to depart from Seattle-Tacoma International Airport.
The new, more powerful 5G radio signals turned on last week at cell towers around the country can potentially interfere with an instrument called an altimeter that’s used to precisely measure how high a plane is above the ground. That data is fed into other systems and a false reading could endanger the aircraft.
The FAA has imposed limitations on low-visibility flying to avoid 5G interference with cockpit instruments. That has created a problem specific to the Embraer E175 regional jets that operate out of Paine Field and to certain airports, including Paine Field and Portland International Airport.
Gaining FAA clearance depended on the model of altimeter used on each aircraft and also how close the cell towers at each airport were to the runways.
Horizon’s Q400 turboprop planes use altimeters from Collins, which were cleared everywhere. But Joe Sprague, Horizon Air’s president, said that the specific Honeywell altimeter on the E175 jet required airport-specific limitations.
The FAA therefore cleared the E175 to use only runways further away from the cell towers.
While the E175 was barred from using one runway at Sea-Tac Airport, it was cleared for the runway there that’s most typically used for low visibility conditions. That “effectively gave us good coverage for Sea-Tac,” said Sprague.
Passengers scheduled to fly out of Paine Field should check their flight status before setting out for the airport.
Staff reporter Dominic Gates contributed to this report.