NTSB Issues Update on Southwest Flight 1380's Engine Failure
The National Transportation Safety Board issued an investigation update this afternoon regarding Southwest Flight 1380's engine failure on April 17.
The investigative update stated that the Boeing 737's "maintenance records indicate that 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 left CFM-56-B engine of the aircraft experienced a failure of the No. 13 fan blade, which resulted in the loss of the engine inlet and cowling. Fragments from the cowling and engine inlet struck the fuselage, causing a rapid depressurization and requiring an immediate emergency diversion into Philadelphia International Airport (PHL).
An image shared alongside of the update highlighted the damaged components of the 737's left engine. The missing fan blade resulted in the engine's loss of cowling, as well as almost the entire inner and outer barrels of the inlet cowl as well as the forward and aft inlet bulkheads. While the broken fan blade showed significant signs of metal fatigue, no cracks were found on any of the other fan blades even though they "exhibited a combination of trailing edge airfoil hard body impact damage, trailing edge tears, and missing material."
The NTSB update included the agency's summary of an interview with the captain and first officer, the three flight attendants, and a Southwest Airlines employee in the cabin. The cockpit voice transcription team has also completed a draft transcript, which will be released when the public docket is opened.
The update simply summarizes the Board's findings thus far, and the NTSB stated that analysis and conclusions on the incident's probable cause will not be shared until the final report is released. The full update can be found here.
TPG has reached out to several aviation experts for comment, and will update with any responses received.
Image courtesy of the NTSB.