NTSB calls for redesign of component of Boeing 737 NG after deadly incident

WASHINGTON — Federal safety officials on Tuesday recommended that Boeing be required to redesign a key component of its Next-Generation 737 and that airlines retrofit thousands of planes as a result of an investigation into a deadly Southwest Airlines incident last year.

The sweeping recommendations by the National Transportation Safety Board were in response to an April 2018 engine failure on a Southwest flight.

A fan blade broke off and destroyed part of the structure that houses the engine, the NTSB found in issuing its probable cause for the deadly incident. A metal latching mechanism flew out and smashed against the plane, blowing out a window, and leading to a violent decompression that prompted panic in the cabin, investigators said.

Passenger Jennifer Riordan, a philanthropy executive and mother of two from Albuquerque, was seated next to the blown-out window. She was sucked halfway outside the plane and died of blunt impact trauma, a medical examiner found.

The latching mechanism was part of the overall airplane engine-housing structure, known as a fan cowl, that played a key role in the incident.

The NTSB said it is crucial that interactions between different engine and airplane components that affected the deadly incident “be well understood to preclude a failure of the fan cowl structure on Boeing 737NG-series airplanes.”

To that end, the NTSB issued several recommendations to the Federal Aviation Administration.

It said the FAA should require Boeing to “redesign the fan cowl structure on all Boeing 737 next-generation-series airplanes to ensure the structural integrity” of that structure in case of another broken fan blade.

The FAA should also require Boeing to install that redesign on new 737 NG jets, and require airlines to “retrofit their airplanes with the redesigned fan cowl structure,” the NTSB said.

NTSB Chairman Robert

Sumwalt said it is not the role of his organization to consider the costs of such a change, but to make sure planes are as safe they can be with new technologies that have become available in the more than 20 years since the 737 NG was certified. Sumwalt did not fault Boeing for the design issue, saying the company used the best technologies at its disposal back in the 1990s. But there is now an opportunity to make the planes safer, he said.

Sumwalt also said airlines have increased the frequency of inspections and made them more robust, which will enable them to catch cracks in fan blades in the current fleet.

In a statement, Boeing said it is “committed to working closely with the FAA, engine manufacturers” and others to addresses the NTSB’s recommendations.