On April 17th, Southwest Airlines Flight 1380 suffered a catastrophic engine failure 32,000 feet above the ground. The twin-engine Boeing 737 was flying to Dallas from New York with 149 people aboard. The engine partially exploded, sending shrapnel into the fuselage and depressurizing the cabin. One passenger was sucked partially out of the aircraft through a broken window. While other passengers managed to pull her back into the aircraft, New Mexico native Jennifer Riordan would die of her injuries. Seven other passengers were injured.
Captain Tammy Jo Shults, former US Navy pilot and one of the first women to fly an F/A-18 Hornet, brought the aircraft to an emergency landing at Philadelphia International Airport.
It is the first U.S. airline passenger fatality since 2009, but the outcome for Flight 1380 could have been far worse. For Southwest Airlines, the legal ordeals have only begun.
Flight 1380’s engine failure is not the first of its kind for Southwest Airlines.
In August 2016, a similar incident occurred to SWA Flight 3472. Another Boeing 737 flight from New Orleans to Orlando suffered an engine failure mid-flight. Similar to Flight 1380, one of the engine’s fan blades separated from the fan disc. This sent shrapnel from the engine inlet into the fuselage, however, in this instance, the passenger cabin was not compromised.
While separated by two years, the two incidents are similar enough to have raised some alarm. The most important common factor between Flight 1380 and Flight 3472 was not the aircraft itself, but the engines they use. The CFM56 engines are the mainstay of 737s worldwide.
In 2017, the warning signs were enough to prompt some action. That year, the Federal Aviation Administration proposed a rule that would require airlines to perform ultrasound inspections on the type of engine involved with the 2016 incident. The rule has not been approved to go into effect. It is also unclear if the rule could have prevented the April 17th incident. The CFM56-7B, has many variants which may not be covered by the rule as written.
737s grounded as inspections begin in earnest
The reputation of the 737 is one of safety. It is the most successful commercial jetliner in modern history, with the 10,000th rolling off production lines this March. These aircrafts make flights every day for multiple U.S. airlines, the vast majority without incident. The CFM56 engines have seen many thousands of successful flights, with only the 2016 and 2018 incidents blemishing their record.
This has not stopped Southwest Airlines from canceling 40 flights the week because of the incident to inspect aircraft. It has continued to cancel flights to ensure that the inspections, and any required maintenance, take place. To minimize disruptions, the company insists that the inspections will take place overnight. This is in response to an emergency airworthiness directive issued by the FAA, ordering inspections of all similar engines in service.
The primary concern is that the constant wear and tear endured by the CFM56 engines may produce the stress fractures present in the fan blades of Flight 1380. The directive requires that the engines undergo inspections for possible issues within the next 20 days.
Investigators to determine if maintenance or design flaws were a factor
Airlines take aircraft maintenance very seriously, for very obvious reasons. Any accident could ruin a smaller operation. Larger airlines like Southwest could possibly endure similar incidents that do not end like Flight 1380, with costs that potentially go beyond the lawsuits and replacement of the aircraft.
The National Transportation Safety Board has begun an extensive investigation, which will scrutinize the aircraft, and it’s maintenance records. The engines themselves will also have individual logs that record the type of maintenance performed, and when. If investigators uncover that maintenance was inadequate, Southwest Airlines could be on the hook for endangering passengers.
The other possibility is a flaw with the engines or 737s themselves. However, given the long service lives of both engine and aircraft without significant failures, this is less likely. Until this is ruled out, Boeing and engine manufacturer CFM International will both be under a microscope. The two companies have each released statements about the incident, and are cooperating with investigators.
The other interesting factor is the FAA itself. Critics are accusing the FAA of failing to act in the face of impending danger. They believe the organization should have required inspections years ago, particularly in the wake of the 2016 incident. And it appears that the FAA did have some concerns over the CFM56 engines, enough to have proposed its rule in 2017 regarding inspections.
Airline safety has always been a major concern, and in recent years injuries and deaths have seen great reductions. Flight 1380 is an unfortunate reminder that even the friendliest of skies can still be dangerous to the safest of airlines.