The U.S. National Transportation Safety Board formally assumed primary investigation authority for the 10 July Ryanair Boeing 737 NG uncontained engine failure over Greece, where debris shattered a cabin window and partially ejected passenger Ljubisa Karovic. Greece’s HARSIA delegated the probe under ICAO Annex 13 provisions, transferring lead responsibility to the operator’s state. Preliminary data confirms a right-engine fan blade detached shortly after Thessaloniki takeoff, striking the fuselage at approximately 16,000 feet and causing rapid decompression. The 2008-delivered aircraft, operated by Malta Air, returned safely; Karovic sustained friction burns but remains stable. This event mirrors recent Southwest Airlines 737 NG engine integrity concerns, triggering immediate sector scrutiny on blade maintenance protocols and fan disk EIS thresholds.