Why are there separation of powers at the federal, state, and local levels?

Michael manin, an airline pilot, was twice convicted of disorderly conduct, a minor misdemeanor. to renew his flight certification with the national transportation safety board (ntsb), manin filed an application that asked him about his criminal history. he did not disclose his two convictions. when these came to light more than ten years later, manin argued that he had not known that he was required to report convictions for minor misdemeanors. the ntsb’s policy was to consider an applicant’s understanding of what information a question sought before determining whether an answer was false. but without explanation, the agency departed from this policy, refused to consider manin’s argument, and revoked his certification. was this action arbitrary and capricious? 1. the ntsb is an administrative agency.