PHAK 1-11

Figure 1-16. Pilot Operating Handbooks from manufacturers. Figure 1-17. Example of an Advisory Circular in its fifth revision. • Standardize implementation of a regulation or harmonize implementation for the international aviation community • Resolve a general misunderstanding of a regulation • Respond to a request from some government entity, such as General Accounting Office, NTSB, or the Office of the Inspector General • Help the industry and FAA effectively implement a regulation • Explain requirements and limits of an FAA grant program • Expand on standards needed to promote aviation safety, including the safe operation of airports There are three parts to an AC number, as in 25-42C. The first part of the number identifies the subject matter area of the AC and corresponds to the appropriate 14 CFR part. For example, an AC on “Certification: Pilots and Flight and Ground Instructors” is numbered as AC 61-65E. Since ACs are numbered sequentially within each subject area, the second part of the number beginning with the dash identifies this sequence. The third part of the number is a letter assigned by the originating office and shows the revision sequence if an AC is revised. The first version of an AC does not have a revision letter. In Figure 1-17, this is the fifth revision, as designated by the “E.” Flight Publications The FAA, in concert with other government agencies, orchestrates the publication and changes to publications that are key to safe flight. Figure 1-18 illustrates some publications a pilot may use.