Boeing Max 9 aircraft was banned from long flights over water

The Alaska Airlines plane that lost part of its fuselage in mid-air on Friday was not used on long flights over water because a pressure warning light went off during three recent flights, the National Transportation Safety Board said Sunday.

Jennifer Homendy, chairman of the board, said it is too early to say whether the issue played a role in Friday’s incident, which led to the grounding of 171 Boeing 737 Max 9 planes in the United States. “It is certainly a concern and it is one we want to look into,” Ms. Homendy said at a news conference in Portland, Oregon.

She said Alaska Airlines maintenance personnel had been assigned to determine why the warning light had repeatedly gone off, but that the work was not done before the flight on Friday. Instead, Ms. Homendy said, workers reset the system and the plane was put back into service, although the airline limited its use on flights to destinations such as Hawaii.

She said the security council was trying to get more information about what happened on the three flights when the lights went out, all of which had taken place since December 7.

The Friday incident on Alaska Airlines Flight 1282, bound for Ontario, California, occurred at an altitude of 16,000 feet and forced the pilots to return to Portland International Airport shortly after takeoff. None of the 171 passengers and six crew on board were seriously injured, but they were exposed to the howling wind from the hole in the fuselage as the pilots made the emergency landing.

Authorities have focused their attention on a plug in the center cabin door, part of the fuselage piece that was torn from the plane. Ms. Homendy said Sunday that investigators recovered the door plug from the backyard of a home in Portland. Door plugs are used to fill emergency exits that are not needed because the aircraft is configured with less than the maximum possible number of seats.

Ms Homendy also said there was no information on the voice recorder in the plane’s cockpit because the device starts recording again after two hours, erasing the previous data, and it was not retrieved in time. Ms Homendy said the safety board, which has pushed for the period to be extended from two hours to 25 hours, has conducted 10 investigations since 2018 where the cockpit voice recorder was similarly overwritten.

“Cockpit voice recorders are not just useful for the NTSB to use in investigations or for the FAA to use in investigations,” she said. “They are critical in helping us accurately determine what was going on.”

Ms Homendy said the force of the decompression during the Friday incident blew open the cockpit door, causing one of the pilots to lose a headset. Headrests were detached from the seats, backrests disappeared and clothing was scattered throughout the plane.

Sunday was the board’s first full day of investigation into the episode, which has drawn new attention to the Max plane and its troubled history. The Max was grounded worldwide after two Max 8 jets crashed within months in 2018 and 2019, killing hundreds of people.

On Saturday, the Federal Aviation Administration announced mandatory inspections for 171 Max 9 aircraft used by U.S. airlines. Alaska Airlines, which owns 65 of these aircraft, canceled 170 flights on Sunday because of the order. United Airlines, which has 79 Max 9s, more than any other airline, said it canceled about 270 flights this weekend.