Mechanics had performed visual and fluorescent penetrant inspections of the fan blades in the CFM56-7B turbofan that failed during an April 17 flight of a Southwest Airlines Boeing 737-700 within the period required by Federal Aviation Administration rules, the U.S. National Transportation Safety Board revealed in a May 3 investigative update.

The May 3 NTSB update confirmed the fan blade at the center of the investigation into the April 17 accident had separated at the root; the dovetail remained installed in the fan disk.

The report also described the sequence of events during which flight attendants reported hearing a loud sound and feeling vibration. After the oxygen masks deployed, they retrieved portable oxygen bottles and began moving through the cabin to calm passengers and assist them with their masks. As they moved toward the mid-cabin, they found the passenger in row 14 partially out of the window and attempted to pull her into the cabin.  – AINonline

Featured image by video screen capture