FAA wants more fan blade checks

Engine part was implicated in fatal April 17 accident

DALLAS — The Federal Aviation Administration is calling for more frequent, ongoing inspections of tens of thousands of engine fan blades in airline fleets across the U.S. to check for “unsafe conditions” in the wake of the fatal April 17 Southwest accident.

The agency cited the “risk to the flying public” in calling for more frequent inspections on 3,716 CFM56-7B engines installed on U.S. airplanes — each engine has 24 fan blades.

The latest regulatory move comes about 20 months after a similar midair engine failure forced an emergency landing.

The agency released an updated airworthiness directive, scheduled to be published Wednesday, that supplements an emergency order put out days after the accident, when a fan blade broke off a Southwest engine aircraft, sending debris into the plane and causing a window to blow out. A passenger sitting next to the window later died from her injuries.

The National Transportation Safety Board said after the accident that the broken fan blade showed signs of interior cracking, known as metal fatigue. A similar incident occurred in 2016 when a fan blade broke off an engine on a Southwest flight from New Orleans to Orlando.

“This (airworthiness directive) addresses the unsafe condition affecting CFM56-7B engines by requiring initial and repetitive inspections of fan blades based on accumulated fan blade cycles,” the directive said. “This condition, if not addressed, could result in fan blade failure due to cracking, which could lead to in an engine in-flight shutdown, uncontained release of debris, damage to the airplane, and possible airplane decompression.”

The engine involved in the accident is one of the most common types used to power 6,700 aircraft worldwide. It’s manufactured by CFM International, a joint company of General Electric and France’s Safran Aircraft Engines.

The FAA’s emergency directive issued April 20 called for ultrasonic inspections of fan blades in engines with more than 30,000 takeoffs and landings within 20 days. The updated advisory is expected to go into effect at or near the end of that 20 day-window, the FAA said.

It will add new requirements for the initial inspection of engines not affected by the emergency directive and recurring inspections for all engines.