The NTSB issued an investigative update Thursday for its ongoing investigation of the fatal, April 17, engine failure on Southwest Airlines flight 1380.
The Boeing 737, powered by CFM International engines, experienced a failure of the left CFM-56-B engine after departing New York’s LaGuardia Airport. The engine experienced a failure of a fan blade, which resulted the loss of the engine inlet and cowling. Fragments from the cowling and engine inlet struck the fuselage, causing a rapid depressurization. The crew conducted an emergency descent and diverted to Philadelphia International Airport. There were 144 passengers and five crewmembers onboard. One passenger suffered fatal injuries and eight passengers suffered minor injuries. The airplane was substantially damaged.
According to the investigative update, the aircraft’s maintenance records indicate, the fan blades were last overhauled 10,712 engine cycles before the accident. At the time of the last blade overhaul (November 2012), blades were fluorescent penetrant and visually inspected.
The investigative update includes a summary of the interviews conducted by the NTSB with the captain and co-captain, the three flight attendants, and a SWA employee in the cabin.
The cockpit voice recorder group has completed a draft transcript of the incident. The CVR transcript will be released when the public pocket is opened.
The information in the update is preliminary and subject to change as the NTSB’s investigation progresses. Analysis of the accident facts, along with conclusions and a determination of probable cause, will come at a later date when the final report on the investigation is completed. As such, no conclusions about how the incident happened should be drawn from the information contained within the preliminary report.
The incident marks the first fatality involving a U.S. registered commercial passenger air carrier since the 2009 Colgan Air flight 3407 crash near Buffalo, New York.