Investigations Process
While the initial field phase of an accident investigation can be concluded within weeks or even days, the investigators' final report and recommendations often take years to complete. Sometimes the investigative agency holds a public hearing, with witnesses, to gather additional information and opinions about what the evidence shows. NTSB investigations conclude with a "sunshine meeting" in Washington, D.C., at which the board votes on the official findings of fact and probable cause. Its final report also includes recommendations to the parties, the vast majority of which are implemented, often before the investigation is complete.
Always important to an investigation are the "black boxes" - the cockpit voice recorder and flight data recorder, which are encased in steel boxes located in the tail of every plane and capable of withstanding great pressure and temperature extremes. Radar tapes also can be valuable sources of information to accident investigators.