The National Transportation Safety Board, or NTSB, is a United States government agency responsible for the investigation of civil transportation accidents.
In 2013, the HYDRA-orchestrated crash of UPS Airlines Flight 1354 took place. One of the responding agencies was the NTSB, who uncovered evidence of HYDRA involvement in the crash. They were assisted in their investigation by the FBI. This information eventually wound up in Arnim Zola's preserved mind under Camp Lehigh, in Wheaton, New Jersey.