Alaska Airlines had placed restrictions on a Boeing 737 Max 9 aircraft following three pressurization warnings in the days before the plane was involved in a mid-air door-covering blowout on Friday, investigators say.
The jet had been prevented from making long-haul flights over water, according to Jennifer Homendy of the U.S. National Transportation Safety Board. Homendy said the decision was made following the warnings so that if the plane had a pressurization problem it could land at any nearby airport.
[ Alaska Airlines flight: Plane's door found ]
Homendy said pilots reported pressurization warning lights on three previous flights made by the specific Alaska Airlines 737 Max 9 involved in the incident, according to BBC News.
The plane that left Portland, Oregon, had 177 passengers and crew onboard when a part of the fuselage blew out, leaving a gaping hole in the plane and causing oxygen masks to drop from the ceiling.
The force of the depressurization caused a child to have his shirt sucked from his body, according to the boy’s mother.
One passenger, Diego Murillo, said the gap left by the missing component was “as wide as a refrigerator.” According to the NTSB, the missing section of the plane was found in the backyard of a Portland teacher.
The plane was able to return to Portland and land safely.
It is not clear whether there is a link between the warning lights and whatever caused the blowout, but “An additional maintenance look” was requested but “not completed” before the plane took off on Friday, Homendy said.
The incident prompted Alaska Airlines to ground all of its Boeing 737 Max 9 planes. The plane involved in the incident was new and delivered to Alaska Airlines in October.
The Federal Aviation Administration ordered the grounding of some Boeing Max 9 planes operated by U.S. airlines or flown into the country by foreign carriers until they are inspected, according to the AP. The emergency order affects about 171 planes worldwide.
The flight that left Portland on Friday reached 16,000 feet before it began its emergency descent, according to flight tracking data.