The Federal Aviation Administration on Friday ordered ultrasound inspections of hundreds of jet engines like the one that blew apart at 32,000 feet in a deadly accident aboard a Southwest Airlines plane.
The agency said the order affects 352 engines in the U.S. on new-generation twin-engine Boeing 737s, a workhorse jet widely used by airlines around the world.
The National Transportation Safety Board believes one of the engine fan blades snapped on the Southwest flight Tuesday, hurling debris that broke a window and led to the death of a passenger who was sucked partway out of the 737. The jet, which was headed from New York to Dallas with 149 people aboard, made an emergency landing in Philadelphia.
NTBS investigators said the fan blade that broke off was showing signs of metal fatigue — cracks from repeated use that are too small to be seen by the naked eye.
The FAA acted after engine maker CFM International issued a service bulletin earlier in the day recommending even wider inspections than it called for last June.
The FAA order and CFM’s service bulletin reflected concerns that more engines could have faulty fan blades than originally thought.
Under the FAA order, all CFM 56-7B engines that have gone through at least 30,000 takeoffs or landings must be inspected within 20 days.
In its own service bulletin Friday, CFM, a joint venture between General Electric Co. and France’s Safran SA, went further, recommending inspections by the end of August of all engines that have gone through at least 20,000 flights.
Altogether, CFM 56-7B engines are on about 1,800 of the 737s in service in the U.S. and about 6,400 worldwide.
Jennifer Riordan, a 43-year-old bank executive from Albuquerque, New Mexico, died in Tuesday’s accident.
The NTSB also blamed metal fatigue for the engine failure on a Southwest 737 in Florida in 2016 that was able to land safely.