14 CFR § 158.20 - Submission of required documents.
(2) Any transmission to FAA Headquarters, using regular U.S. Postal Service, is subject to inspection that may result in delay and damage due to the security process.
(b) Once the database development is completed with air carrier capability, public agencies and air carriers may use the FAA's national PFC database to post their required quarterly reports, and, in that case, do not have to distribute the reports in any other way.
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