“Whatever final conclusions are reached,Boeing is accountable for what happened. An event like this must not happen on an airplane that leaves our factory,” said Boeing chief executive Dave Calhoun.
The US Federal Aviation Administration (FAA) grounded 171 Boeing 737 Max 9’s after the incident,most operated by US carriers United Airlines and Alaska Airlines,for inspections. Those planes were cleared to return to service in late January.
The US National Transportation Safety Board (NTSB) report released on Wednesday (AEDT) focused on how the panel – fitted to this Max 9 model in place of an optional exit – could have detached from the aircraft. The plug is held down by four bolts and secured by “stop fittings” at 12 different locations along the side of the plug and the door frame.
The plug was manufactured by Spirit AeroSystems,a former subsidiary of Boeing. The part was produced at its facilities in Malaysia and delivered to Spirit’s Kansas facility in May 2023. It arrived in Washington on August 31.
The report shows the panel had to be removed at Boeing’s Renton,Washington,factory before being reinstalled. The initial findings include photo evidence that bolts required to hold it in place appeared to be missing.
The panel was first removed to repair rivet damage logged by Boeing workers on September 1,2023,the report noted,a day after arriving in Renton. Investigators are still trying to determine what documentation was used to authorise the opening and closing of the plug during the rivet repair.