Boeing will increase quality inspections and review the work of suppliers as part of a review of the production processes for its 737 aircraft in response to the incident involving the mid-flight loss of a door plug on an Alaska Airlines 737 MAX 9. 

Steps taken by the company will include sending a team to inspect Spirit AeroSystems' installation of the type of door plug that was involved in the incident and allowing airlines that operate 737s to visit its factories. 

In a memo sent to employees, Boeing Commercial Airlines President and CEO Stan Deal said: “We have taken important steps in recent years to strengthen our Quality Management System’s (QMS) foundation and its layers of protection. 

“But, the AS1282 accident and recent customer findings make clear that we are not where we need to be. To that end, we are taking immediate actions to bolster quality assurance and controls across our factories.” 

The aircraft manufacturer’s announcement comes a few days after the Federal Aviation Administration (FAA) said it would increase oversight of production at Boeing following the launch of its investigation into the aircraft manufacturer. 

The US aviation regulator will conduct an audit of the 737 MAX 9 production line and its suppliers to determine whether additional investigations are necessary while also increasing its monitoring of MAX 9 in-service events. 

FAA Administrator Mike Whitaker said: “The grounding of the 737-9 and the multiple production-related issues identified in recent years require us to look at every option to reduce risk. 

“The FAA is exploring the use of an independent third party to oversee Boeing’s inspections and its quality system.” 

The announcement comes just a few days after Boeing was informed of the FAA’s investigation into the company, which will determine whether it failed to ensure products conformed to the approved designs and were in safe operating condition. 

In addition to the Alaska Airlines incident itself, additional scrutiny has come after both United Airlines and Alaska found loose parts during the mandated inspections of the MAX 9s in their fleet, including bolts that needed additional tightening. 

All MAX 9s with a door plug in the US remain grounded by the FAA as it carries out its investigation with the regulator stating: “The safety of the flying public, not speed, will determine the timeline” for returning the aircraft to service.