Boeing has responded to a damning National Transportation Safety Board (NTSB) preliminary report which found that four critical bolts were missing from a door plug that blew out on a Boeing 737 Max 9 plane last month, sparking a midair emergency.
“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,” CEO Dave Calhoun said in a statement following the release of the report on Tuesday.
“We simply must do better for our customers and their passengers.”
The company said it is implementing a comprehensive plan to strengthen the quality of its aircraft and boost the confidence of its stakeholders following the incident.
It had previously been reported that the plane’s door plug – a panel of the fuselage near the rear of the aircraft – had left the plane’s manufacturing plant without the critical bolts needed to keep it in place.
In the NTSB’s report, investigators found that four key bolts were missing from the plane. These bolts are usually in place to prevent the door plug’s upward movement, the NTSB said.
According to the report, the damage to the aircraft was consistent with the door plug moving upward, outward and being ejected from the aircraft. The NTSB previously said that all 12 stop fittings had disengaged.
“Overall, the observed damage patterns and absence of contact damage or deformation around holes associated with the vertical movement arrestor bolts and upper guide track bolts in the upper guide fittings, hinge fittings, and recovered aft lower hinge guide fitting indicate that four bolts that prevent upward movement of the MED plug were missing before the MED plug moved upward…