The biggest mystery going into a series of National Transportation Safety Board hearings about Boeing’s 737 Max 9 door plug blowout incident remains a mystery. An initial NTSB investigation into what caused the coverup for an unused emergency door to disappear into the sky mid-flight this January found that four key bolts that were supposed to keep it in place were not bolted on.
Boeing supplier Spirit AeroSystems sent the incomplete fuselage of the Alaska Airlines plane in question from Wichita, Kansas to Renton, Washington last September. It was part of a practice called “traveled work,” so that Spirit crews could finish the work along Boeing crews in order to keep Boeing production speeds on track. Nils Johnson, an NTSB investigator, asked Boeing executive Elizabeth Lund if she knew whether it was Spirit or Boeing workers who forgot to replace the missing bolts.
“We have no knowledge of who closed the plug on the 19th,” he said. “I want to understand if you know something that I don’t.”
Lund responded in the negative
“I do not have any knowledge beyond what you described,” she said.
CNN reports that during a break between hearing sessions, NTSB chair Jennifer Homendy told reporters gathered for the proceedings that Lund’s lack of knowledge was sub-optimal.
“We don’t know and neither do they and that’s a problem,” she said.