United Airlines and Alaska Airlines have said that they had found loose parts on some of their Boeing 737 Max 9 jets after a fuselage panel blew out during an Alaska flight Friday, adding to growing safety concerns about the Max 9.
The disclosures followed reports that Alaska Airlines had been warned three times before the Friday flight about problems with cabin pressure on the plane. Those warnings were significant enough that the airline had decided the plane, a Max 9, could no longer be used on flights to Hawaii.
United said Monday that it had found loose bolts in the panels, known as door plugs in the industry, after starting to take out seats and sidewall liners for inspections this weekend. The plugs are placed where an emergency exit door would be if a jet had more seats. Alaska Airlines said later in the day that technicians preparing Max 9 jets for inspections after the mid-air emergency had discovered “loose hardware” in some cases.
A door plug suddenly flew off the Alaska Airlines plane Friday as cabin pressure dropped about 10 minutes after take-off from Portland, Oregon, subjecting passengers to howling wind and forcing pilots to quickly return to the airport. The door plug, phones, toys and other personal items all streamed out of the hole in the side of the plane and fell across the city.
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Airlines have cancelled hundreds of flights as they prepare to inspect nearly 200 aircraft that will be grounded until regulators and company officials decide they are safe. Alaska Airlines used 65 Max 9 planes, about 20 per cent of its fleet, and United used 79, more than any other airline and about 8 per cent of its fleet, said Cirium, an aviation data provider. Some passengers’ travel plans could be disrupted for days.
The Federal Aviation Administration sent instructions to the airlines early Monday on how to carry out the inspections. United said late in the day that it was still waiting on additional approval from the FAA before it could begin inspections. Alaska said it was waiting on guidance from both Boeing and the FAA to begin. But technicians from both airlines have nevertheless begun preliminary inspection work, they said.
Officials led by the National Transportation Safety Board are focusing on, among other things, the installation and inspection of the plug.
“I think investigators are going to be focused on the manufacturing process of this particular aeroplane,” said Jeff Guzzetti, a former investigator for the NTSB and the FAA “How was this door plug installed or who installed it?”
The door was initially installed by Spirit AeroSystems, which makes the body for the 737 Max and other aircraft. Investigators said they were looking into whether work had been carried out on or near the door since the plane entered service in November.
Jennifer Homendy, chair of the NTSB, said investigators had a great deal of work to do, including inspecting the plug, which was recovered from a backyard near Portland. The board will also examine a plug that remained intact on the other side of the plane, interview flight crews and passengers, review maintenance records and repair logs, and conduct laboratory analyses of parts from the plane.
Investigators may also look into whether the installation of wireless internet equipment on the plane by a contractor, AAR, between November 27th and December 7th played any part in the pressurisation problems, which emerged after that work was complete. In a statement, AAR said Monday that it “did not perform any work on or near any midcabin exit door plug of that specific aircraft”.
While no serious injuries were reported, the crash could have been far more catastrophic, especially if the plane had been at a higher altitude, experts said. Ms Homendy said Sunday night that the passengers had included three babies and four unaccompanied children between the ages of 5 and 17.
Ms Homendy said in a brief interview Monday that her team was reviewing the plane’s flight data recorder to try to determine if the pressurisation warning light could be linked to the door plug. The plane has several backup systems in case one of the pressurisation systems fails.
“There may have been something wrong with either the light or that one other unit, but there’s redundancies in the system,” Ms Homendy said.
In a statement, the FAA said the required inspections would concentrate on the plugs, door components and fasteners.
“Our teams have been working diligently – with thorough FAA review – to provide comprehensive, technical instructions to operators for the required inspections,” Stan Deal, chief executive of Boeing’s commercial plane unit, and Mike Delaney, the chief aerospace safety officer, said in a message to employees of that unit Monday.
Federal authorities investigating the incident are also looking into what set off pressurisation warnings on the damaged plane during three recent flights. Alaska Airlines workers reset the system, and the plane was put back into service, though the airline restricted it from being used on flights to destinations such as Hawaii, Ms Homendy said. She said that it was not yet clear if the warnings were related to the crash on Friday.
In a statement, Alaska said it could not answer many outstanding questions about the plane and what had led to the blowout without approval from the safety board. The airline said it had asked the NTSB to share more information and would do so if allowed. In such investigations, parties are typically restricted in what they can share publicly.
Boeing chief executive Dave Calhoun planned to host a company-wide safety meeting Tuesday to discuss the company’s response to the episode and reaffirm its commitment to safety. Boeing is still working to secure approval of the smaller Max 7 and larger Max 10.
Boeing shares closed down about 8 per cent on Monday, and shares of Spirit AeroSystems closed down 11 per cent. – This article originally appeared in The New York Times.
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