Section 13.3 - Investigations (general)(a) The Administrator may conduct investigations; hold hearings; issue subpoenas; require the production of relevant documents, records, and property; and take evidence and depositions.(b) The Administrator has delegated the authority to conduct investigations to the various services and offices for matters within their respective areas.(c) The Administrator delegates to the Chief Counsel, each Deputy Chief Counsel, and the Assistant Chief Counsel for Enforcement the authority to:(2) Conduct formal investigations;(3) Subpoena witnesses and records in conducting a hearing or investigation;(4) Order depositions and production of records in a proceeding or investigation; and(5) Petition a court of the United States to enforce a subpoena or order described in paragraphs (c)(3) and (4) of this section.(d) A complaint against the sponsor, proprietor, or operator of a federally assisted airport involving violations of the legal authorities listed in § 16.1 of this chapter must be filed in accordance with the provisions of part 16 of this chapter.