A door that flew off a Boeing 737 Max mid-flight may not have been properly attached, according to a new safety report.
Four bolts appear to have been missing from a door panel that blew off a Boeing plane during an Alaska Airlines flight on 5 January, according to a new report from the US National Transportation Safety Board.
“Whatever final conclusions are reached, Boeing is accountable for what happened,” Boeing CEO, Dave Calhoun, said in response to the findings.
“An event like this must not happen on an airplane that leaves our factory. We simply must do better for our customers and their passengers. We are implementing a comprehensive plan to strengthen quality and the confidence of our stakeholders.”
Tuesday’s report shows that the door plug, manufactured by Boeing’s supplier Spirit AeroSystems, was originally installed and then later removed in the Boeing factory.
The panel was taken off to repair rivet damage, yet when it was reinstalled, three of the four bolts were not put in.
It is still unclear whether the bolts were missing before they reached the Boeing factory, or whether they were taken out whilst repairs were underway.
Investigators have criticised the manufacturers for failing to properly document their workings.
“It is a series of problems,” Senator Tammy Duckworth, who chairs an aviation subcommittee, said in an interview. “What is going on between the maintenance and inspection teams… Holy cow – nobody noticed?”
Although it caused no casualties, last month’s panel blowout has brought Boeing under heavy regulatory scrutiny, and the recent report is likely to deepen the company’s reputational damage.
The US Federal Aviation Authority has already blocked Boeing from expanding production of its best-selling, single-aisle 737 MAX jets.
A number of the manufacturer’s customers, notably Emirates and United Airlines, have also suggested they will be scaling back orders of Boeing planes.
The Federal Aviation Authority is about halfway through its six-week inspection of Boeing’s factories, an investigation that will also look at fuselage production at Spirit.
Boeing shares closed up 1% on Tuesday. The stock has lost more than 20% of its value since the beginning of the year.