Defect deurbeslag Alaska infographic
Graphic shows door plug and location of failed fittings


Deurbeslag sleutel tot veiligheidsonderzoek

By Duncan Mil

January 9, 2024 - U.S. regulators have grounded all Boeing 737 MAX 9s after United Airlines and Alaska Airlines discovered loose bolts on door plugs following an emergency landing by an Alaska jet.

The U.S. Federal Aviation Administration grounded 171 Max 9 planes on Saturday after a panel in the fuselage of an Alaska Airlines Max 9 blew off just minutes after taking off from Portland, Oregon, on Friday.

The event has raised serious concerns over the possibility of broader safety issues affecting the popular variation of Boeing’s 737 airliner.

A National Transportation Safety Board (NTSB) investigator said late Monday (January 8) that an initial examination of the recovered door plug and the hole left in the airframe when the part blew out showed that two guide roller tracks, one on each side near the top of the door plug were fractured.

In a media briefing, NTSB engineer Clint Crookshanks said that the fractures did not cause the plug failure but happened as the panel broke away.

Finding out what happened to the four bolts on the Alaska accident flight is emerging as a critical task in the NTSB’s probe.

“We have not yet recovered the four bolts that restrain it from its vertical movement and have not yet determined if they existed,” Crookshanks said.

A closer examination of the plug and other parts would reveal if each bolt worked itself free or failed.

PUBLISHED: 09/01/2024; STORY: Graphic News