During which investigation can the NTSB participate?

The National Transportation Safety Board (NTSB) is an independent U.S. government agency responsible for investigating various types of transportation accidents, including those in aviation, highway, marine, pipeline, and railroad sectors. The NTSB typically participates in investigations that have broad implications for public safety and involve multiple agencies or industries.

In the context of interagency investigations, the NTSB engages with other federal, state, and local agencies to gather comprehensive findings and develop insights that can enhance transportation safety. This collaboration can involve sharing expertise, data, and resources from various governmental organizations, thereby contributing to a more thorough understanding of the incident and its implications for safety regulations and practices.

Other types of investigations mentioned, such as Class A mishaps and ground mishap safety reviews, may not involve the NTSB directly, as they can be overseen or conducted by specific agencies or military branches without the NTSB's participation. This helps clarify why the interagency investigation is the correct answer, highlighting the NTSB's role in situations that require multi-agency collaboration for effective safety oversight.