Loose bolts on the plane are a concern – may indicate system failure

The door plug came loose, leaving a large hole in the cabin at an altitude of thousands of meters. Now the industry hopes that it is not a system error – but loose bolts on other levels have turned on warning lights.

– It leans towards some kind of quality control problem, says aviation expert Kathleen Bangs.

The rectangular piece looks relatively undamaged, despite falling 5,000 meters and ending up in a teacher’s garden outside Portland, in the US state of Oregon.

– It is remarkable that they found the door, if it had ended up in a lake or river, this investigation would have taken much longer, says Kathleen Bangs, American aviation safety expert and pilot.

– The fact that the hole has a clean cut surface leads one to believe that it was clearly not a bomb, and it is probably not a matter of structural weaknesses, such as metal corrosion, either, she continues.

Landed safely

The Alaska Airlines plane had just taken off from the Portland airport when the panel dislodged, causing cabin pressure to drop and objects to be sucked out of the hole. The plane had then reached 5,000 meters, but had not yet reached cruising altitude, which is usually at least twice that.

– I was a little surprised that several rows of chairs bent, that headrests and people’s mobile phones flew out of their hands. I’m amazed at the power of the decompression at that altitude, says Bangs.

The pilot was able to quickly turn the aircraft around and land safely back in Portland, and no one was injured.

No real door

Kathleen Bangs explains that it is not an airplane door, but a plugging of a door frame, created for an emergency exit that is not needed when you have less than 200 passengers.

– This type of door has been used before, and there have been no problems. It is not a radical new design, says Bangs.

It was probably something in the door plug itself, or the surrounding frame, that failed, she thinks. The accident investigation agency NTSB will closely examine the parts.

The failure may have been due to damage during transport of the aircraft part, a vehicle at the airport backing into it, or a subcontractor accessing it while working on something on the plane.

– It’s almost what you hope for, that it received a very rare injury, she says.

New problems

The door plug is fixed with four bolts in the door frame. United and Alaska airlines, which own the lion’s share of the plug-door model in question, have also found loose bolts on other planes of the same model during post-accident inspections.

– It looks like we have some kind of quality control error, says Bangs.

For Boeing, the accident is another credibility blow, after the two fatal accidents with other Max planes in 2018-2019. With those accidents fresh in their minds, there are many who question safety, according to her.

– But in the end, Boeing is too big to fail. It’s not just an aircraft manufacturer, they have a space program and are a defense supplier. But it’s clear that they obviously need to steer the boat correctly, says Kathleen Bangs.