Aircraft hijacking (also known as airplane hijacking, skyjacking, plane hijacking, plane jacking, air robbery, air piracy, or aircraft piracy, with the last term used within the special aircraft jurisdiction of the United States), is the unlawful seizure of an aircraft by an individual or a group. Dating from the earliest of hijackings, most cases involve the pilot being forced to fly according to the hijacker's demands. However, in rare cases, the hijackers have flown the aircraft themselves and used them in suicide attacks – most notably in the September 11 attacks – and in several cases, planes have been hijacked by the official pilot or co-pilot; i.e., the Lubitz case.