On Tuesday, April 17, 2018 at 10:27 a.m. Southwest Airlines Flight 1380 departed New York’s LaGuardia Airport bound for Dallas, Texas. As the aircraft was climbing to cruising altitude west of Philadelphia, passengers described what sounded like an explosion from the left side of the aircraft. As alerts and alarms blared in the cockpit, the aircraft experienced a rapid decompression and oxygen masks dropped from the cabin ceiling. The left engine, referred to as the Number 1 engine, suffered a catastrophic fan blade failure which sent engine debris into the fuselage and caused a window behind the engine to break. Tragically, due to the broken window and the change in air pressure as a result, a passenger, who was wearing her seat belt was sucked into the open window as air rushed out of the cabin. Passengers did all they could to pull the woman back into the cabin but unfortunately, she suffered significant blunt force injuries as she was pulled through the open window and hit by debris from the broken engine. Although passengers performed CPR on the passenger for 20 minutes, even as the disabled aircraft was landing, the passenger was pronounced dead at a local hospital after the plane’s flight crew conducted an emergency landing at the Philadelphia International Airport. Seven other passengers suffered physical injuries in this terrifying event. The engine that broke apart was a model CFM56-7B22 engine, manufactured by CFM International, which is a joint venture between General Electric and Safran Aircraft Engines.
This is an event that should not have happened. On August 27, 2016, Southwest Airlines Flight 3472 also experienced an engine blade failure at cruising altitude as it was travelling to Orlando, Florida. Fortunately, no one was injured in that event, but information released by the National Transportation Safety Board indicated that the engine suffered a catastrophic blade failure which required an emergency landing in Pensacola, Florida. It is believed that the fan blade failed due to a fatigue fracture of the blade. As a result, in August 2017, the Federal Aviation Administration issued what is known as a Notice of Proposed Rulemaking (“NPRM”) as a precursor to issuing an Airworthiness Directive (“AD”). In this circumstance, the NPRM was a document published by the FAA wherein it advised the aviation industry that it intended to issue an AD that would mandate certain inspections to detect any unsafe conditions in certain turbine engine disks, just like the engine on Flight 1380. The NPRM allowed the aviation community to comment and Southwest Airlines did just that. It opposed the FAA’s 12-month time frame to carry out the non-destructive inspections, claiming that it needed at least 18 months to conduct the proposed inspections since it had more than 732 such inspections to complete. Unfortunately, as of the Southwest Flight 1380 tragedy, the FAA had not yet made a final decision as to the NPRM, and it is unknown when the last inspection of the failed fan blade took place. Southwest has issued a statement, however, claiming that the next scheduled inspection of the fan blade that failed was to occur in December 2018.
Preliminary information released by the NTSB in the Flight 1380 investigation indicates that investigators believe that, just as in the August 2016 event, the fan blade broke off mid-flight because of metal fatigue and microscopic cracks from repeated use. It is likely that once the fan blade separated it was thrown about the engine at extremely high speed since the fan blade spins at several thousand revolutions per minute. This then caused parts of the engine to break away. Indeed, engine debris was found approximately 70 miles away from Philadelphia International Airport. Undoubtedly, the NTSB investigation will focus on the way the fan blade failed, and what can be done to ensure that nothing similar happens again. The investigation will also look at how the passenger window failed and whether any corrective action is needed. However, the NTSB has already determined that the failed blade exhibited fatigue failure, and this is something that a proper inspection and maintenance schedule must be designed to detect and prevent.
Prior engine failure accident investigations have spurred meaningful change in the aviation industry. Nonetheless, the August 2016 event should have been a wake-up call to Southwest and CFM International that its engines may suffer from catastrophic fatigue defects. Had Southwest conducted an ultrasonic inspection of the fan blade, it is likely that the fatigue cracks would have been discovered and the Flight 1380 incident would not have occurred. There is no question that the NTSB will re-visit the August 2016 event in connection with the Flight 1380 accident investigation. Speiser Krause is closely monitoring the accident investigation and we expect that additional action by the NTSB and the FAA will be issued as the investigation continues.