Some people think that the National Transportation Safety Board is the final authority over an aviation accident — that the NTSB acts as the accident "police."  They think that, in the end, the NTSB will catch the one responsible for the accident and make that person answer for what happened.  But that’s just not the case.

It’s true that, like a cop, the NTSB can secure an accident scene and keep others away.    It can examine the aircraft wreckage. It can have aircraft parts tested to help determine why the accident happened. It can even subpoena evidence. But the NTSB investigates a crash for one reason only: to gather and then publish information so that similar accidents may be avoided in the future.

Although it is an agency of the federal government, the NTSB has no enforcement powers. That means that the NTSB can’t bring criminal charges. It can’t fine anyone. The NTSB can’t suspend anyone’s license as a result of what it learns, and it can’t put anyone out of business. If the NTSB concludes that someone, such as a maintenance facility, was responsible for the crash, that facility is free to ignore the findings and carry on business as usual. 

When the NTSB is done with its investigation, it prepares a report. The report usually includes the NTSB’s opinion as to the accident’s "probable cause."  The hope is that the aviation community will read the report and learn something from it.  Because that is the report’s only permissible purpose, by federal law, the opinions in the report are inadmissible in any lawsuit arising from the crash. 

Sometimes the NTSB, as a result of what it learns, will publish a safety recommendation.  Often the recommendation is that the FAA pass tougher regulations.  But the FAA need not follow the NTSB’s recommendations, and frequently chooses not to.   

If there is a lawsuit concerning the crash, the NTSB will not get involved.  Not only is the NTSB’s report of the accident’s probable cause inadmissible, but the NTSB investigators are prohibited by law from testifying in court, even if they are served with a subpoena.