NTSB finds shattered engine part caused Ryanair window failure over Greece

During the rapid decompression, the co-pilot's head was partially drawn toward the ruptured window before being pulled back inside the aircraft. The crew declared an emergency and returned to the airport, where the plane landed without further injury. Passengers were evacuated on the runway after the aircraft came to a stop.

Why the plane circled before landing

Greek aviation authorities, the Hellenic Aviation and Rail Safety Investigation Authority, opened the inquiry and then formally delegated the investigation to the NTSB under international aviation norms that allow the state of registry of the aircraft manufacturer or the state with the most expertise to lead. Greece retained participation in the investigation, ensuring its investigators had access to the wreckage and the flight-data evidence.

The Boeing 737 involved in the incident had been in service with Ryanair, one of Europe's largest low-cost carriers. NTSB investigators are now examining whether the engine part that fractured had shown prior signs of wear or had missed a maintenance inspection. The agency has not yet said whether it will issue an urgent safety recommendation to operators of similar aircraft.

Ryanair chief executive Michael O'Leary told reporters shortly after the event that the airline was cooperating fully with investigators. The Associated Press sent requests for comment about the NTSB findings to Ryanair, which did not immediately respond to a follow-up request.

A rare but well-documented failure mode

Aviation safety experts said cockpit-window failures are rare but have occurred in past incidents, most famously in 1990 on a British Airways flight over southern England, when a cracked windscreen led to a similar decompression and the captain was partially pulled out of the aircraft. That crew also landed the plane safely, and the episode became a textbook case in crew-resource-management training.

Investigators are expected to publish a final report setting out the cause of the engine-part fracture and any recommendations for inspections of the same component across the 737 fleet. Until then, Ryanair has said it will continue operating its 737s but is reviewing maintenance records on engines of the same type as a precaution.

The NTSB's involvement highlights how cross-border investigations work in practice: when an aircraft, engine or component is designed and manufactured in one country but operated in another, responsibility for the technical inquiry often shifts to the country with the deepest expertise, while the country where the incident occurred maintains a seat at the table.

Cross-border investigation process

Greek authorities said they were satisfied with the delegation and would adopt any safety measures recommended by the NTSB. European aviation regulators, including the European Union Aviation Safety Agency, have been kept informed of the inquiry's progress, according to officials familiar with the case.

No passengers or other crew members were seriously injured in the event. The pilot who was partially drawn toward the window received medical treatment on the ground and was released the same day, according to a Ryanair statement at the time of the incident.