Four of the bolts securing the panel of a Boeing 737 MAX 9 Alaska Airlines jet that blew off mid-flight last month were missing, according to a preliminary investigation published Tuesday.
The National Transportation Safety Board's initial report into the January 5 incident said the lack of damage or deformation around the holes "indicate that the four bolts that prevent upward movement of the (door) plug were missing before the plug moved upward off the stop pads."
