Greek F-16s Sent Up After 'Unresponsive' Civilian Aircraft – Greek City Times
A Code Renegade command brought the Greek authorities to a state of alert after a corresponding signal was received from the NATO air traffic control centre in Spain (CAOC Torrejón) about a civilian aircraft that did not respond to air traffic control. The Renegade Code is usually a distress signal that the aircraft has been hijacked.
Source: greekcitytimes.com