In a preliminary report released by the National Transportation Safety Board (NTSB) on Tuesday, it was revealed that four bolts designed to prevent the door plug from falling off the Boeing 737 Max 9 plane were missing before the plug blew off during an Alaska Airlines flight last month.
The report stated that Boeing records reviewed by the NTSB showed damaged rivets on the edge frame forward of the plug, which were replaced by Spirit AeroSystems employees at Boeing’s factory in Renton, Washington, on Sept. 19, 2023. According to the report, Boeing had to open the plug by removing the two vertical movement arrestor bolts and two upper guide track bolts for the rivets to be replaced.
However, photo documentation obtained from Boeing showed evidence that the plug was closed with no bolts in three visible locations, according to the NTSB report. The investigation into the incident is ongoing, with further updates expected as more information becomes available.