Latest: Southwest Boeing 737 engine failure

On 17 April 2018, a Southwest Airlines Boeing 737-700, registration N772SW on flight WN-1380 from New York La Guardia to Dallas Love, Texas suffered an uncontained engine failure whilst climbing through FL320. In the aftermath of the incident the NTSB (National Transportation Safety Board) made it know that a passenger had died as a result of the incident, and that an investigation was ongoing.

In a second media briefing, the NTSB stated that blade #13 of 24 on the left hand CFM56 engine had separated at the hub, and that there was evidence of metal fatigue. Whilst the NTSB did not go into specifics around the deceased passenger, it is understood that she was seated in seat 14A, and that she may have been partially sucked out of the window as a result of explosive decompression, before being pulled back into the aircraft by passengers next to her. The autopsy report has yet to be completed.

Post incident inspection by FAA

The incident was a great example of fantastic airmanship by the entire crew of Southwest 1380. ATC recordings have subsequently surfaced of the incident, and former US Navy F-18 fighter pilot Captain Tammie Jo Shults set a fantastic example of calm professionalism in the face of an exceedingly stressful situation.

Captain Tammie Jo Shults

The incident may well have opened old wounds for the FAA and Soutwest Airlines, as shortly after the incident it became known that the incident shared marked similarities with a previous incident involving a Southwest Airlines 737-700 in 2016, where a similar blade separation event took place. In fact, the two incidents are so similar, that the damage suffered to the aircraft is almost exactly the same as the previous incident, with the inlet cowl separating completely. The damage suffered to the fuselage as a result of engine debris was also very similar.

An airworthiness directive was issued by EASA (European Airspace Safety Agency) less than a month ago (March 26, 2018), which stated: “An occurrence was reported of fan blade failure on a CFM56-7B engine. The released fan blade was initially contained by the engine case, but there was subsequent uncontained forward release of debris and separation of the inlet cowl. Preliminary investigation determined that the fracture in the blade initiated from the fan blade dovetail. This condition, if not detected and corrected, could lead to fan blade failure, possibly resulting in uncontained forward release of debris, with consequent damage to the engine and the aeroplane.” The FAA had previously released a similar directive, but it did not apply to the 7B variant of the CFM56, which was the variant in question on both Southwest incidents.

This latest incident could very well spark a fresh airworthiness directive from the FAA, and would mean that all US based CFM56 powered aircraft would have to undergo ultrasonic inspection of each fan blade, which could have far reaching consequences for airlines such as Southwest, who operate large fleets of CFM56 powered aircraft.

Gerard Griessel

Technical Writer at AerospaceJournal.com

You may also like...

Leave a Reply

Your email address will not be published.