Apparent engine fan blade failure preceded rupture of Ryanair 737 window

Air safety reporting is made accessible without a subscription as a public service. Subscribe to The Air Current for full access to our scoops, in-depth reporting and industry analysis.

The rupture of a Ryanair Boeing 737-800 window Friday morning was preceded by an apparent failure of a fan blade from its right engine, a CFM International CFM56-7B, people familiar with the accident told The Air Current. 

A fan blade failure is a rare but serious safety issue that aircraft manufacturers and regulators rigorously test for during the certification process. Aircraft engines are designed to contain any main fan blade failure. In April 2018, a Southwest Airlines 737-700 suffered an uncontained blade-out event that killed one passenger after they were partially sucked out of the aircraft. That followed an August 2016 failure aboard another Southwest flight which did not result in any fatalities. 

Those events spawned Federal Aviation Administration airworthiness directives to mitigate the risk of a fan blade failure through inspections and a redesign of the engine inlet to ensure containment. The FAA set a July 31, 2028 deadline for compliance. In both Southwest incidents, the inlet was torn away from the engine nacelle. 

The NTSB said in a statement that the Aircraft Accident and Incident Investigation Committee (AAIIC) of the Republic of North Macedonia reported to U.S. air safety investigators that the aircraft, operating as Ryanair flight 1879, turned back after departure from Thessaloniki Airport in central Greece after experiencing “a right engine issue and cabin decompression.” 

The NTSB said it has appointed an accredited representative to assist with the investigation, and that technical advisors are “standing by to assist” from the FAA, Boeing and GE Aerospace, which together with Safran makes the CFM engines. The AAIIC did not respond to a request for comment outside normal business hours.

Following the safe landing of the flight, the airline said one passenger received medical attention after witnesses described them being partially sucked out of the aircraft. 

“Safety is our top priority,” a CFM spokesman said in an emailed statement. “CFM is supporting our customers and assisting with the investigation. Our thoughts are with the passengers, pilots, and crew who were onboard.” 

“Boeing is assisting the investigation led by the Aircraft Accident and Incident Investigation Committee of the Republic of North Macedonia,” the plane maker said in a statement. “Our thoughts are with the passengers and crew of flight FR1879. We remain in contact with and continue to support our customer, Ryanair.”

Editor’s note: This story has been updated to include a comment from Boeing.