The preliminary report from US investigators regarding the door panel incident on a Boeing 737 MAX 9 jet that occurred mid-flight on January 5 has shed light on the circumstances leading up to the frightening mishap. According to the report, the door panel appeared to be missing four key bolts, raising concerns about potential quality control lapses and safety protocols within the aircraft manufacturing process.
The incident has sparked widespread concern among the flying public and lawmakers, prompting demands for answers regarding the cause of the panel detachment. This event has evolved into a significant safety and reputational crisis for Boeing, the manufacturer of the aircraft.
In response to the incident, Boeing CEO Dave Calhoun issued a statement acknowledging the company’s accountability for what happened. He emphasized the need for continuous improvement in ensuring the safety and reliability of aircraft leaving the factory.
Following the incident, the US Federal Aviation Administration (FAA) grounded 171 Boeing 737 MAX 9 planes, primarily operated by US carriers United Airlines and Alaska Airlines, for inspection. Subsequently, the planes were cleared to return to service in late January, with nearly all of them resuming flights.
The report released by the US National Transportation Safety Board (NTSB) focused on how the panel, which was fitted into the MAX 9 model as part of an optional exit, could have detached from the aircraft. It highlighted that the plug is held in place by four bolts and secured by “stop fittings” at various locations along the side of the plug and the door frame.
Representative Rick Larsen, the top democrat overseeing the FAA, described the failure to reinstall bolts on a safety-critical component as a serious error, indicating broader quality control lapses that require correction.
The investigation revealed that the plugin, manufactured by Spirit AeroSystems in Malaysia, was delivered to a facility in Kansas before being sent to Boeing’s assembly plant in Washington. The report suggested that the bolts required to hold the plug in place were missing, and the panel had been removed for repair shortly after its arrival in Renton, Washington.
Investigators are still working to determine the documentation used to authorize the opening and closing of the plug during the repair process, raising questions about the initial installation of the bolts and the documentation of the door opening procedure.
Boeing has stated that it has implemented a control plan to ensure that all 737-9 mid-exit door plugs are installed according to specifications, indicating a commitment to addressing the identified issues and preventing similar incidents in the future.
While the door panel was recovered, the missing bolts were not found. Extensive tests and analysis were conducted to determine whether the bolts were present before the incident or had come undone during the flight, underscoring the complexity of the investigation and the importance of thorough analysis in ensuring aviation safety.