The day before a door plug popped off on an Alaska Airlines flight on January 5, the airline’s engineers and technicians were so concerned by mounting evidence of the problem that they grounded the flight the next evening for maintenance. I was hoping to receive it. , interviews and documents show.
But the airline opted to operate its Boeing 737 Max 9 planes with some restrictions on January 5, carrying passengers until the end of three flights that were scheduled to end that night. Airline maintenance facility.
The door plug exploded at an altitude of 16,000 feet, minutes after the plane embarked on its second flight, before completing its scheduled series of flights and entering maintenance checks. That day’s flight was from Portland to Ontario International Airport in California.
Although the plane landed safely and no one was seriously injured, the incident has brought new attention to Boeing’s manufacturing processes and the safety procedures followed by airlines.
The schedule for maintenance and inspection of the plane has not previously been reported. This indicates that the airline chose to keep the plane in service while it headed to a maintenance facility rather than fly it to Portland without passengers.
Alaska Airlines acknowledged the sequence of events. However, the airline said the warnings on board the plane did not meet the criteria for immediate grounding.
Donald Wright, Alaska Airlines’ vice president of maintenance and engineering, said warning signals indicating a problem with the plane’s pressurization system have been triggered twice in the past 10 days, rather than the three times the airline believes the triggers. He said the lights were on. More aggressive action.
Alaska Airlines has repeatedly maintained that electronics or other issues may have caused the warning light to turn on, and that there is no evidence it is related to the impending plug explosion.
“From my perspective as a safety official, looking at all the data, all the leading indicators, what would cause me to make a different decision,” said Max Tidwell, Alaska Airlines’ vice president of safety and security. There was no such thing.” interview.
The company’s engineers called for the plane to undergo a rigorous maintenance inspection on January 5 to determine why the warning light came on, based on the use of a “predictive tool” rather than the number of times the warning light went out. was. the airline said.
The airline placed restrictions on its aircraft following the recommendations of engineers, while keeping the planes in service. This restricted the planes from flying long routes over the ocean, such as Hawaii and remote parts of the continent, in case an emergency landing was needed.
Extensive evidence of potential problems with the plane had been accumulating for days and even weeks, according to interviews with the airline and records from the investigation into the explosion. Investigators said that in addition to the flashing lights, the door plug was gradually sliding upwards, a potentially important link in the growing body of evidence. The airline said visual inspections in the days leading up to the explosion showed no movement of the door plug.
Door plugs are panels installed at the emergency exits of aircraft, which can expand the number of passenger seats.
Four bolts that hold the door plug in place were missing before the panel was removed from the plane, according to a preliminary report released last month by the National Transportation Safety Board. The report outlines a series of events at Boeing’s Renton, Washington, factory that may have resulted in aircraft being delivered without these bolts in place.
Mark Lindquist, an attorney representing passengers on the Jan. 5 plane, said the series of accidents involving Alaska Airlines planes was troubling, and that the airline and Boeing, the manufacturer of the 737 Max 9, He added that both sides would struggle to explain what happened in court.
Lindquist said, “If the jury learned that we had actually been warned by engineers to land the plane and then put the plane into commercial rotation, they would not only be confused, they would be furious.” Deaf,” he said.
Lindquist said in a court filing that a passenger on the previous flight heard a “whistling sound” coming from near the door plug. Passengers reported the noise to flight attendants, who reported it to the pilot, the document said. Asked about the report, Alaska Airlines said it could find no record of a report of a whistle blowing from the plane.
The 737 was grounded on Dec. 31, nearly a week before the explosion, due to a problem with the passenger door. The planes returned to service on Jan. 2, but on Jan. 3, at least one plane had a pressurization warning light illuminated during the flight, records show. Alaska Airlines officials said the plane was examined by technicians and the airline determined it was safe enough to continue flying.
The next day, the same light came on again.
An Alaska Airlines spokesperson said at the time that engineers and technicians were scheduled to conduct a detailed inspection of the plane in Portland on the evening of January 5th. However, the airline chose to allow the plane to continue flying within the country with passengers on board that day.
The warning signs of a potential problem were revealed, raising questions about whether regular inspections could have factored in the various signs of trouble and prevented the incident.
Jennifer Homendy, chairwoman of the National Transportation Safety Board, told reporters last week that on 154 flights since the plane entered service in the fall, small upward movements of the door plugs have left visible marks, possibly resulting in collisions with the aircraft. He said there was a gap between them. panel and fuselage.
Alaska Airlines officials said an inspection the day before the door plug was removed showed no unusual gaps between the door plug and the aircraft.
Additional evidence includes reports of pressurized system lights and unidentified whistling sounds from previous flights.
