Boeing shares drop after door panel blows out mid-flight

After an Alaska Airlines flight made an emergency landing Friday, shares of Boeing and its parts supplier Spirit AeroSystems have dropped amid renewed concerns about the safety of Boeing’s 737 Max aircraft.

was found in the backyard of Portland, Oregon on Sunday.

The plug door – a panel installed to replace an emergency exit in certain versions of the 737 Max 9 – tore from the plane shortly after it tookoff from Portland Airport, bound for Ontario and California.

After the incident on Friday, US regulators ordered that all Max 9 models equipped with door plugs be temporarily grounded pending inspections. The consequences of the accident could have been far more serious if the closest seats had not been occupied and the passengers still wore seatbelts.

The hole was described as “as large as a fridge” and the wind that blew out of it was powerful enough to take the shirt off the teenage boy who was sitting near it. However, the plane managed a safe landing with no injuries.

The US National Transportation Safety Board has launched an inquiry and stated that the discovery of a missing door plug which fell near the house of a teacher would be “key”.

Jennifer Homendy said that the incident was “terrifying”.

The cockpit voice recorder will not be used as evidence in the investigation because it was overwritten with only two hours’ worth of data.

Homendy said that the Alaska Airlines plane had also been subjected to three automatic cockpit alerts over cabin pressure in its first two months of service.

She said that the auto pressurisation failure light had been triggered three times: on 7 December, 4 January and 3 January. However, it is unclear whether there was a connection between these events and Friday’s near disaster.

Homendy stated that the airline decided to limit the plane’s long-range flights over water, in case of a repeat warning.

Indonesia has grounded the three Max 9 aircraft operated by Lion Air until further notice, despite their having a working exit door. Lion Air was the first to suffer a major crash that led to the 737 Max being withdrawn worldwide from service in 2019. The crash was eventually blamed on problems with the flight control software.

The shares of Boeing fell 9% at the opening of Wall Street, but recovered some losses by Monday afternoon to fall 7%. Spirit AeroSystems shares were down by 14% at the opening of Wall Street, but later eased to 8%.

Senior, another Boeing supplier, was down 3% on Monday.

Spirit produces the door parts at its Wichita plant, Kansas. However, they are fitted semi-completed according to a Reuters report. Boeing removes the plug during the next stage of production at its Renton, Washington factory, when it is fitting out the interior. Investigators will look for any defects in the assembly of both companies.

Boeing plans to host a virtual company-wide meeting on safety Tuesday, following the incident.

Dave Calhoun, the chief executive of the company, said in a Sunday message that the response was “the focus” and “must be”. He added: “When accidents such as this happen, it’s critical for us to work with transparency with our customers and regulatory bodies to understand and address causes and ensure they don’t occur again.”

Alaska Airlines cancelled 60 more flights on Monday, and warned that disruptions would continue until at least the middle of the week.

United Airlines, the largest operator of this model, grounded 79 Max 9s and cancelled 230 scheduled flights on Sunday. This represents 8% of all departures.

According to EASA, the EU safety regulator and EU aviation authority, no European airline operates the 737 Max 9 with the configuration in question.