14 CFR 158.20: Submission of required documents.

(a) Letters and reports required by this part may be transmitted to the appropriate recipient (the public agency, air carrier, and/or the FAA) via e-mail, courier, facsimile, or U.S. Postal Service.

(1) Documents sent electronically to the FAA must be prepared in a format readable by the FAA. Interested parties can obtain the format at their local FAA Airports Office.

(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.