Boeing Co (NYSE:BA, ETR:BCO) has said teams are being sent directly to supplier Spirit Aerosystems to run quality checks after a door plug blew off one of its 737 Max 9 jets earlier this month.
“Our team is now inspecting Spirit’s installation of the mid-exit door plug and approving them before the fuselage section can be shipped to Boeing,” Boeing's commercial chief executive, Stan Deal, said in an update.
“We are also inspecting more than 50 other points in Spirit’s build process and assessing their build plans against engineering specifications.”
Both Boeing and Spirit have faced intense scrutiny after a panel blew out of an Alaska Air-operated Max 9 mid-flight on 5 January.
US authorities subsequently grounded the models, affecting some around 170 jets globally, with domestic operators Alaska Air and United Airlines being the hardest hit.
Both carriers have since reported finding “loose” parts in the door plugs on some grounded planes, prompting questions over the quality checks at Boeing and of parts sourced from Spirit.
Boeing added external parties would be brought in to assess production and quality control procedures at both its own factories and those operated by Spirit.
“We are taking immediate actions to bolster quality assurance and controls across our factories,” Deal added.
Shares in Boeing have been hit following the incident, falling 15.3% so far this year.