Regulators have called on Boeing to redesign the fan cowl structure on thousands of its 737 NG planes and retrofit existing planes after a fatal accident in 2018 in which a woman was killed after she was nearly sucked out of a window.
The passenger was killed on a Dallas-bound Southwest Airlines plane in April 2018 when a broken fan blade caused an engine failure and punctured a three-pane window. The woman, 43-year-old Jennifer Riordan of New Mexico, was partially sucked out of the aircraft briefly.
An investigator of the fatal accident, The National Transportation Safety Board (NTSB), on Nov. 19 determined that the structure of the 737 Next Generation series airplanes should be updated to minimize the potential of a catastrophic failure and to prevent such an accident from happening again in the future.
It called for a redesign of the engine cowling—the removable cover of the engine—to prevent debris from hitting the plane should an internal piece come loose in the future.
Boeing has delivered about 7,000 737 NG planes to customers around the world, but has halted new orders for the model as it shifts to the 737 Max, which are not affected by the issue, according to Teal Group data.
The company said on Tuesday it would work to implement improvements that address the NTSB’s safety recommendations, including improvements in “the inlet and fan cowl designs to enhance their ability to withstand an engine fan blade out event.”
“Our common goal is to help prevent similar events from happening in the future,” Boeing said, citing “safety and quality” as its top priorities.
The NTSB did not call for the planes to be grounded and noted that airlines are now inspecting the fan blades on a more regular basis. However, a number of Boeing 737 NGs have been grounded due to safety issues including cracks being discovered on some older aircraft on a part used to keep the wings in place.
“This accident demonstrates that a fan blade can fail and release differently than that observed during engine certification testing and accounted for in airframe structural analyses,” said NTSB Chairman Robert Sumwalt in a statement.
He acknowledged the retrofit could be expensive.
“It is important to go beyond routine examination of fan blades; the structural integrity of the engine nacelle components for various airframe and engine combinations needs to be ensured,” Sumwalt added.
Southwest spokesman Chris Mainz said the airline would review the NTSB’s recommendations and work “with the manufacturers to prevent this type of event from ever happening again.”
In a news release, Boeing said its design changes and enhancements will be implemented in the existing NG fleet once approved by the Federal Aviation Administration. The FAA told Bloomberg it will review and respond to the NTSB recommendations.
Boeing added: “Our thoughts remain with the family and friends of Jennifer Riordan, who died from her injuries, with those who were hurt, and with all of those onboard.”
Reuters contributed to this report.