Boeing, the aircraft manufacturer, has acknowledged responsibility for the incident involving the 737-9 variant, where a mid-exit door panel dislodged during flight.

Boeing President and CEO Dave Calhoun said in a statement on Monday that the company appreciates the US National Transportation Safety Board’s (NTBS) work and will review their findings expeditiously.

Mr Calhoun said they will continue to cooperate fully and transparently with the NTSB and the FAA investigations.

“Whatever conclusions are reached, Boeing is accountable for what happened. 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 the quality and the confidence of our stakeholders. It will take significant, demonstrated action and transparency at every turn – and that is where we are squarely focused,” he said.

The official said Boeing is taking immediate action to strengthen quality. First, the company has implemented a control plan to ensure all 737-9 mid-exit door plugs are installed according to specifications.

The company has also instituted new inspections of the door plug assembly and similar structures at its supplier’s factory and on Boeing’s production line and added signage and protocol to fully document when the door plug is opened or removed at the firm’s facility, ensuring it is reinstalled and inspected prior to delivery.

Moreover, Mr Calhoun said Boeing is implementing plans to improve overall quality and stability across the 737 production system.

This will include layering additional inspections further into the supply chain and collaborating with suppliers on production enhancements, performing more work on airplanes at their assigned positions and dedicating multiple days for its 737 teams to focus on and implement quality improvements.

The firm will also launch an independent assessment to bolster the quality management system at Boeing Commercial Airplanes by a highly experienced safety expert.

“This added scrutiny – from ourselves, from our regulator and our customers – will make us better. It’s that simple,” said Mr Calhoun.