Kathmandu— A fractured engine fan blade caused debris to shatter a window on a Ryanair Boeing 737-800 aircraft flying from Thessaloniki, Greece, to Memmingen, Germany on July 10th, partially pulling a 61-year-old passenger into the opening and causing cabin depressurization. United States air safety investigators with the National Transportation Safety Board (NTSB) have identified evidence of metal fatigue in the failed blade, though the root cause of the failure remains under investigation. The injured passenger suffered neck and shoulder injuries but was treated by a doctor on board and successfully pulled back into the cabin by fellow passengers.

Fatigue Found on Failed Blade

The NTSB’s preliminary report indicated that approximately 37 percent of the fracture surface on the failed fan blade exhibited features consistent with fatigue. Investigators pinpointed damage near the root of the blade, revealing signs of high-amplitude fatigue resulting from repeated stress. While the agency has not yet determined what initially caused the blade to fail, the presence of metal fatigue is a key finding in the ongoing investigation.

Incident Details and Cabin Response

The aircraft was climbing through 16,000 feet when pilots received a high-vibration alert from the right engine. The vibration escalated rapidly before a loud bang occurred, leading to cabin depressurization. Fragments from the engine penetrated the fuselage, shattering the window at row 11. A flight attendant discovered the passenger in seat 11F partially lodged in the opening and passengers were able to pull him back into the cabin. Other passengers attempted to block the opening with a metal box from the galley.

Prior Bird Strike History

Investigators recovered feathers and bird remains within several parts of the engine, but have not yet concluded that a bird strike caused the blade failure. Maintenance records revealed four suspected bird strikes involving the same engine in the year prior to the incident, with physical remains found after two of those events. The engine’s fan blades had undergone ultrasonic inspections in November 2025 and May 2026, during which no damage was detected.

The NTSB investigation is ongoing as they continue to analyze the cause of the blade failure and assess any potential safety implications.

(With inputs from Al Jazeera)

Originally published on abcnews.com.np.