Aviation safety authorities in the United States and Europe have opened an investigation into what caused the near catastrophic incident aboard a Ryanair Holdings Plc flight from Greece to Germany, during which a cabin window detached and threatened to drag out the passenger seated beside it.

The US Federal Aviation Administration (FAA) said on Monday that it is supporting an investigation by the National Transportation Safety Board (NTSB) and has sent experts to examine the Boeing aircraft. The agency is also assessing whether the failure has parallels with previous incidents involving CFM56-7B engines, which are manufactured by CFM International, a joint venture between General Electric’s aerospace division and the French firm Safran.

The European Union Aviation Safety Agency (EASA) said separately that it is in constant contact with the FAA and has appointed a technical advisor to take part in the inquiry. EASA said it would continue to monitor developments and take any airworthiness action needed as more information emerges.

The investigation is being led by North Macedonia’s Aircraft Accident and Incident Investigation Committee, since the incident occurred in that country’s airspace as the aircraft climbed away from Thessaloniki. The NTSB has appointed an accredited representative to assist, while technical advisers from the FAA, Boeing and GE Aerospace are also supporting the inquiry. CFM International said it was working closely with the relevant authorities.

The Boeing 737-800, registered 9H-QEU and operating on behalf of Ryanair’s Malta-based subsidiary, Malta Air, made an emergency landing back at Thessaloniki on the morning of Friday, 10 July, shortly after the cabin window detached.

Investigators believe the failure began with an apparent fan blade breaking away inside the aircraft’s right-hand CFM56-7B engine, with debris from the turbine then striking and shattering the window.

The scenario has drawn comparisons with two earlier Southwest Airlines incidents involving the same engine type: a 2016 fan blade separation that caused fuselage damage but no serious injuries, and a fatal 2018 event in which debris from a similar failure shattered a window and killed a passenger. Those cases led the FAA to order enhanced fan blade inspections and a redesigned engine inlet intended to better contain debris, with airlines required to comply by 2028.

“I grabbed him by the legs”

The passenger involved, 61-year-old Ljubisa Karovic from Serbia, was seated next to the window when it shattered, causing a rapid loss of cabin pressure that pulled him towards the opening with his head and shoulders forced outside the fuselage.

His wife, Svetlana Grkovic, who was seated beside him, reacted immediately. “It was as if a piece of the engine had broken off and hit the window next to where Ljubisa was sitting. I reacted immediately and grabbed him by the legs. I thought: if we’re going to die, we’ll die together. It was horrific,” Grkovic told Serbian broadcaster Nova.

She held onto her husband for about five minutes until other passengers rushed over and pulled him back into the cabin, by which point the oxygen masks had already dropped. Grkovic said a man and a woman came to help her almost immediately.

“They came to help me. I remember a man and a woman. He helped us a great deal, both me and Ljubisa,” she said, adding that she hopes to meet the pair again to thank them in person.

Karovic remains in hospital. According to his wife, he sustained a serious arm injury and friction burns and is in a state of severe shock. He has been unable to speak because of his injuries, having lost consciousness several times during the incident, and remembers very little of what happened.

Other passengers described chaotic scenes on board. Some initially believed the plane was crashing, while others rushed to help the injured man. “He had blood on his head and kept passing out. We were all wearing oxygen masks and didn’t know if we’d make it,” one passenger said. Another witness said Karovic survived because he had kept his seatbelt fastened. “Fortunately, he hadn’t taken it off. His wife held onto his legs for five whole minutes until the other passengers arrived to pull him inside,” they said.

Ryanair said in a statement that the flight returned to Thessaloniki airport shortly after take-off when a passenger window “dislodged in-flight”. The airline said one passenger received medical attention after landing and that a replacement aircraft was arranged to fly the remaining passengers on to Memmingen. A pregnant passenger was also taken to hospital as a precaution but was found to be in good health and has since been discharged.