Explain how the NTSB can be a reactive organization in terms of accident/incident investigation

Post to this forum your answers to the following question. Again, the rationale supporting your

answers may be more important than the actual answers.

What do you think is the purpose of the accident investigation?

Explain how the NTSB can be a reactive organization in terms of accident/incident investigation (after the fact) yet, still be a proactive safety organization.