A fan blade on the No. 2 engine of a Ryanair Boeing 737 fractured due to metal fatigue, tore through the engine casing, shattered a cabin window and partially pulled a passenger out of the aircraft before fellow travelers dragged him back inside, the National Transportation Safety Board said in a preliminary report released Thursday.
The flight departed Thessaloniki, Greece, on July 10, bound for Memmingen, Germany. Less than 10 minutes after takeoff, at roughly 16,000 feet, the crew received a warning for high engine vibrations. Nearly two minutes later, vibrations intensified sharply and the pilots heard a loud bang as the autopilot disengaged. The aircraft turned back and made an emergency landing at Thessaloniki.
The NTSB report identifies the engine as a CFM International CFM56-7B26, a model built through a joint venture between France's Safran Aircraft Engines and GE Aerospace. The CFM56 is among the most widely used commercial jet engines in service worldwide. The blade that separated drove fragments into the fuselage and the right horizontal stabilizer. Shrapnel breached the metal surrounding the engine, shattered the window at row 11, dented the fuselage near row 8, punctured the body below the wing and gouged the tail section.
Ljubisa Karovic, 61, seated in seat 11F, had his head and shoulders drawn through the broken window. His wife, who was also on board, told Reuters that she and a flight attendant pulled him back into the cabin. She described his injuries as serious. The NTSB report describes Karovic as having been "partially lodged in a damaged cabin window" and confirms that other passengers helped retrieve him.
Investigators found evidence of fatigue cracking on the remains of the separated blade. Fatigue cracking is the gradual fracturing of metal under repeated stress—in this case, stress that exceeded what would be expected given the number of flight cycles the blade had accumulated. Eight additional blades on the same engine showed deformation along their leading edges.
Bird remains, including feathers, were recovered from the damaged engine. The NTSB said four suspected bird strikes had been reported in the year before the incident, but inspections after each of those events found no damage. It was not established whether any of those strikes contributed to the blade's condition.
The 18-year-old Boeing 737-8AS had undergone a fan blade inspection fewer than three weeks before the July 10 incident, a check required under a rule put in place after a comparable event in 2018. That year, a Southwest Airlines Boeing 737 suffered a fan blade separation that shattered a window; a passenger was partially drawn outside and later died from blunt force trauma. The FAA mandated enhanced inspections of CFM56 fan blades following that fatal accident.
The Hellenic Air and Rail Safety Investigation Authority requested that the NTSB lead the inquiry, a step permitted under international aviation agreements. Greece is participating as an accredited representative in the investigation.
The NTSB's findings conflict with public statements Ryanair CEO Michael O'Leary made during a July earnings call, in which he offered a characterization of the incident that the report contradicts on the question of how the passenger came to be at the window and how he was recovered. The report does not elaborate on O'Leary's specific claims, but notes the discrepancy.
The preliminary report does not assign final cause or apportion responsibility. The NTSB will conduct further analysis of the fractured blade, including examination of the fatigue cracking pattern and any role the reported bird strikes played in accelerating metal degradation.
