Aircraft hijacking 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. There have also been incidents where the hijackers have overpowered the flight crew, made unauthorized entry into the cockpit and flown them into buildings—most notably in the September 11 attacks—and in some cases, planes have been hijacked by the official captain or first officer, such as with Ethiopian Airlines Flight 702.