Advisory Circulars provide an acceptable means of compliance with Civil Aviation Rules.

To see a list of ACs we are working on and new ACs, please check here:

Advisory circulars monthly report [PDF 263 KB]

To provide feedback on ACs, please see the list open for consultation below.

See draft ACs closed for comment


AC66-2.32 Revision 2 - Aircraft Maintenance Engineer Licence—Certificate of Inspection Authorisation (Subject 025) [PDF 234 KB]

This is the second Revision of this AC. It was last updated in February 2014. Revision 2 amends the source material references and provides greater detail on subject matter requirements for the Certificate of Inspection Authorisation (IA).

As with previous ACs, section highlighted in yellow denote insertions, and those in strikethrough denote deletions.

If you would like to provide feedback on these changes, please submit your response to us by Monday 30 August 2021.


AC91-20, Revision 1 - Guidelines for the Approval and Use of Electronic Flight Bag Devices [PDF 618 KB]

This AC describes an acceptable means of compliance with standards for the approval and use of portable and installed Electronic Flight Bag (EFB) devices in aircraft, as related to relevant parts of rules 121, 125 and 135 as listed in Section 4.

This is the first revision of AC91-20, since it was published on 30 January 2012. It updates section 7, Background, and section 8, Evaluation of Portable Hardware Components. It also updates section 9.2, Type B Software Applications, and updates section 12.13, Training. Lastly, it renumbers and deletes duplicate sections, with the effect that section 10 in the first version is now much of section 8, section 11 has been largely deleted and what was section 13 in the previous version is now section 12. Section 12 to 12.12 is largely unchanged – while this revision focuses on technological change, a review of operational approval processes may be the focus of the next revision.

As with previous ACs, section highlighted in yellow denote insertions, and those in strikethrough denote deletions.

If you would like to provide feedback on these changes, please submit your response to us by Monday 9 August 2021.

Advisory circulars closed for comment

AC121-1 (draft) Revision 1 – Extended Diversion Time Operations and Polar Area Operations [PDF 1 MB]

AC121-1, Extended Diversion Time Operations and Polar Area Operations, is attached for feedback. This is Revision 1 of this AC. The update supports revised rules governing aeroplane diversions greater than 60 minutes flight time from an adequate aerodrome. The revised standard encompasses the operations of all turbine powered multi engine Part 121 aeroplanes and replaces the previous extended-range twin-engine operations (ETOPS) rules which applied only to extended range operations in twin turbine engine aeroplanes.

Because this AC was last updated in 2000, it has been substantially rewritten to account for technical changes. Therefore it was felt a marked-up version which compared changes against the initial Revision would not be helpful. It is recommended that readers go through this draft as a stand-alone document.

Comments closed 27 July 2021


AC171-1 (draft) Revision 2 - Aeronautical Telecommunication Services - Operation and Certification [PDF 472 KB]

Comments closed 28 June 2021


AC61-10 (draft) Revision 11 – Pilot Licence and Ratings – Type Ratings [PDF 450 KB]

Comments closed 18 June 2021


AC21-7 (draft) Revision 0 – Product Certification – Type Certificates [PDF 1.1 MB]

AC21-7 (draft) Revision 0 - Appendix A - CCL Template draft [PDF 95 KB]

AC21-7 (draft) Revision 0 - Appendix B - PSCP Template draft [PDF 266 KB]

Comments closed 13 May 2021


AC43-1 (draft) Revision 5 – Aircraft Maintenance [PDF 360 KB]

Comments closed 10 May 2021


AC12-1 (draft) Revision 5 - Mandatory Occurrence Notification and Information [PDF 460 KB]

Comments closed 10 May 2021


AC139-12 (draft) Revision 1 - Aerodromes—Certification, Operation and Use - UNICOM and AWIB Services [PDF 377 KB]

Comments closed 27 April 2021


AC91-1 & AC172-1 – Radiotelephony Manual [PDF 1.1 MB]

Comments closed 23 April 2021


AC61-13 (draft) Revision 3 - Pilot license and ratings - Glider Tow Rating [PDF 164 KB]

Comments closed 22 April 2021


AC175-1 (draft) Revision 3 - Aeronautical Information Services Organisations [PDF 460 KB]

Comments closed 15 April 2021