14 CFR 414.13 - Confidentiality.
(a) To ensure confidentiality of data or information in the application, the applicant must -
(1) Send a written request with the application that trade secrets or proprietary commercial or financial data be treated as confidential, and include in the request the specific time frame confidential treatment is required.
(2) Mark data or information that require confidentiality with an identifying legend, such as “Proprietary Information,” “Proprietary Commercial Information,” “Trade Secret,” or “Confidential Treatment Requested.” Where this marking proves impracticable, attach a cover sheet that contains the identifying legend to the data or information for which confidential treatment is sought.
(b) If the applicant requests confidential treatment for previously submitted data or information, the FAA will honor that request to the extent practicable in case of any prior distribution of the data or information.
(c) Data or information for which confidential treatment is requested or data or information that qualifies for exemption under section 552(b)(4) of Title 5, U.S.C., will not be disclosed to the public unless the Associate Administrator determines that withholding the data or information is contrary to the public or national interest.
(d) If the proposed criteria for evaluating a safety approval is secret, as classified by the U.S. Government, or the applicant wants it to remain proprietary or confidential, it cannot be used as a basis for issuance of a safety approval.