A plane crash is the unplanned collision of an airplane. The airplane may be operated by a commercial airline or it can be a private plane. The accident can happen in the air or on the ground during takeoff or landing. General aviation accidents typically result in more fatalities than other types of plane accidents when adjusted for flight hours flown. Federal regulations require that all plane crashes be reported to the National Transportation Safety Board (NTSB) for investigation. The Federal Aviation Authority (FAA) also investigates significant plane crashes and aviation accidents.