The NTSB said on Thursday that Greek authorities had delegated responsibility for leading the investigation to the U.S. agency, which will work with other aviation authorities and stakeholders to determine what caused the incident.
The event occurred on July 10 shortly after the aircraft departed from Thessaloniki, Greece, on a flight bound for Germany. According to video footage and information from the Federal Aviation Administration, a piece of the aircraft’s engine separated and struck a passenger window, causing a loss of cabin pressure.
The Boeing 737 NG was forced to make an emergency landing after the damage occurred.
A passenger, Serbian national Ljubisa Karovic, was partly pulled toward the broken window during the incident. Fellow travellers reportedly held onto him until the aircraft landed safely. Karovic sustained injuries and was taken to hospital for treatment.
Investigation Raises Questions Over Boeing 737 NG Safety
The incident has drawn attention because of similarities with two previous accidents involving Southwest Airlines Boeing 737 NG aircraft in 2016 and 2018.
In the 2018 Southwest incident, a passenger died after being partially pulled out of a window that had been damaged by debris from a broken engine fan blade.
However, Bryan Bedford said early indications suggested the Ryanair incident may not be the same type of failure seen in the Southwest accident.
“I don't think the early indications are that (the recent Ryanair problem) mimics what the Southwest incident was,” Bedford told Reuters in an interview.
FAA Reviews Previous Safety Measures
Following the 2018 Southwest accident, the NTSB recommended that Boeing redesign the fan cowl structure on Boeing 737 NG aircraft to reduce the risk of similar failures.
The FAA later issued an airworthiness directive in 2023 requiring modifications to affected aircraft, with compliance required by 2028.
Bedford said the latest investigation has prompted the regulator to reconsider whether its previous response fully addressed potential risks.
“Did we miss something? Way too early to tell -- but we can't take it off the board yet,” he said.
The FAA administrator stressed that investigators would examine all possible factors before drawing conclusions about whether additional safety actions are required.
Southwest Says Aircraft Modifications Ahead of Schedule
Southwest Airlines said on Thursday that it had completed modifications on about 80% of its affected Boeing 737 NG fleet.
The airline added that it remained ahead of schedule to complete the required work before the FAA’s July 2028 deadline.
Ryanair Fleet Uses CFM56 Engines
Ryanair operates Boeing 737 NG aircraft powered by CFM International CFM56 engines.
The Boeing 737 NG, or Next Generation series, is the predecessor to the newer Boeing 737 MAX family and remains widely used by airlines around the world.
Investigators are expected to examine the engine failure, the damage caused to the aircraft structure, maintenance history, and whether existing safety measures were sufficient.
The outcome of the investigation could influence future recommendations for airlines, regulators, and manufacturers operating Boeing 737 NG aircraft globally.