Which agency is responsible for accident investigation in aviation in the U.S.?

The National Transportation Safety Board (NTSB) is the agency responsible for conducting investigations into aviation accidents in the United States. This independent federal agency is tasked with determining the probable cause of accidents and making recommendations to improve safety and prevent future occurrences. The NTSB has the authority to collect evidence, conduct interviews, and analyze data related to accidents involving commercial and general aviation.

While the Federal Aviation Administration (FAA) oversees the aviation industry by regulating and ensuring compliance with safety standards, it does not conduct accident investigations; rather, it plays a regulatory role. The Department of Transportation (DOT) encompasses a broader range of transportation issues and does not focus specifically on aviation accident investigations. The Transportation Security Administration (TSA) is primarily concerned with security measures in transportation systems and does not handle accident investigations either.

In summary, the NTSB is uniquely positioned and empowered to investigate aviation accidents, making it the correct choice in this context.