The return to service of the 171 Boeing 737 Max 9s that were grounded after a fairing was lost from the fuselage of an Alaska Airlines plane will take longer than expected and result in hundreds of flights being canceled each day. The Federal Aviation Administration says this model of aircraft “will remain grounded until we determine its safety.” It is currently not clear why US authorities decided to spend more time on inspections – initially estimated at 4 to 8 hours per plane – but based on the findings, investigators and experts have not yet fully understood the causes of the separation.
The panel search
The fact that the plate blown away by Alaska Airlines Boeing, which was used on the 737 Max 9 to “plug” the hole in the fuselage where an emergency door is installed if desired, doesn't help either. Police appealed to the public to help search and limit the area west of the outskirts of Portland. The plane took off from the city of Oregon and then had to return after 19 minutes to bring the passengers (171) and crew members (6) to safety after the hole in the cabin.
The accident
The sudden loss of pressure also resulted in the loss of some parts of seat 26A, the seat directly behind the detached fairing. The lack of a seated passenger at that moment, the relatively low altitude (around 5,000 meters) and the fact that the people on board were still wearing seatbelts a few minutes after take-off prevented the worst from happening. However, according to insiders, the accident will increase attention on Boeing, especially in view of the certification process of three other aircraft: the 737 Max 7, the 737 Max 10 and the huge 777X.
Flights canceled
The grounding of the Max 9 has already led to dozens of flight cancellations planned by airlines – especially American ones – with this aircraft variant. According to FlightAware data – updated at 9pm Italy time on Sunday, January 7 – United Airlines canceled 246 flights (9% of all scheduled flights), most due to the grounding of the 737 Max 9. Alaska canceled another 163, 21% than expected (also in this case mainly due to the plane stopping). But cancellations are also recorded at Copa Airlines (55) and Aeroméxico (52). European, Asian and Middle Eastern airlines do not appear to be involved at this time. Max Kingsley-Jones from Cirium Ascend Consultancy analyzes the aircraft's technical specifications and explains that the inspections should concern Aeroméxico, Alaska Airlines, Turkish Airlines and United Airlines.
Who makes the hull?
Technically, the 737 Max's fuselage is manufactured by a company outside Boeing – Kansas-based Spirit AeroSystems – which split from the American aerospace giant in 2005. Spirit then takes care of installing the plate itself, which fills the resulting crack. This part is present in all Max 9 fuselages because in certain configurations – such as those required on low-cost aircraft with more seats on board – it is used to install the exit door immediately after the wings and just before the tailgate. On aircraft with fewer than 189 seats – such as those of Alaska Airlines – these doors are “blocked” with the panel.
The investigations
“We will examine the aircraft's pressure system, we will examine the door and the hinges,” Jennifer Homendy, president of the NTSB (the body that investigates transportation accidents in the United States), said at a press conference. And then she asked, “Based on previous crashes with the Boeing Max, do we suspect there is a general design problem with this aircraft?” At the moment, no. But that “right now” and the FAA’s wording, which many see as bizarre, raise several questions among experts.
Alaska's new catch
All airlines that have this special marking must therefore check the board and ensure that there are no special signs. But before we fly again, we need the green light from the FAA. The US Federal Aviation Administration notice also explains why Alaska Airlines is once again grounding all Max 9 aircraft: further maintenance may be required to ensure that an in-flight explosion does not occur again. In fact, on Saturday, the day after the accident, the company had returned 18 of its 65 Max 9s to service following an inspection.