
A serious defect in one of the right engine blades of a Ryanair Boeing 737 jet triggered a chain of events that led to a window breaking and a passenger being partially sucked in during a flight over Greece on July 10.
Preliminary data released by the US National Transportation Safety Board (NTSB) indicates that the probable cause of the incident was metal damage, accompanied by partial wear in the engine bay.
The plane had departed from Thessaloniki with 155 people on board and was flying to Memmingen in Germany. The problems began during the climb, at an altitude of about 16 thousand meters near Polikastro, a few kilometers from the border with North Macedonia.
According to data recorded by the black box sensors, a significant increase in vibrations was initially observed in the CFM56-7B26 engine. A few minutes later, the situation worsened, while a loud noise was accompanied by the disconnection of the autopilot and the activation of warnings in the cockpit.
Investigators determined that one of the engine blades, specifically number 10, broke off. Its fragments were thrown at high speed, damaging the outer engine cowling and penetrating the lower fuselage.
One of the fragments struck and completely shattered the window next to seat 11F. As a result of the sudden decompression, a passenger was partially pulled towards the opening created in the fuselage, causing panic among passengers and crew.
Oxygen masks automatically dropped, while some passengers tried to cover the opening in the fuselage with improvised means. The pilots managed to stabilize the plane and returned for an emergency landing at Thessaloniki airport.
The investigation has also uncovered another element. The NTSB found bird debris inside the engine, raising suspicion that the plane may have struck birds during takeoff.
However, the pilots did not report any such collision and the engine problem appeared a few minutes after takeoff. For this reason, investigators are analyzing whether there is any connection between the suspected bird strikes and the engine blade failure.
The case has also raised questions about engine maintenance and timely implementation of safety directives.
According to the investigation, parts of the aircraft's engine and structure had not yet received the reinforcements and improvements required by three separate FAA directives issued in 2025.
Ryanair, however, was formally in compliance with the regulations, as the deadline set for carrying out interventions on the fleet runs until July 2028. Investigators are now examining whether this deadline is sufficiently appropriate for safety-critical components.
Another element being analyzed is the engine's maintenance history. According to the NTSB document, it had undergone an ultrasonic inspection just 253 flight cycles before the incident, on May 24, 2026, and no abnormalities were found.
Investigators are also looking into four suspected bird strikes recorded on the same engine during the 12 months prior to the incident.
The investigation continues with the participation of the NTSB, Boeing, GE Aerospace, Safran and the European Aviation Safety Agency, as authorities try to precisely determine the connection between the engine blade failure and the damage to the aircraft's structure.