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 235 KB]

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

See draft ACs closed for comment


AC43-14, Rev 6, Standard Design Changes: Acceptable Technical Data [PDF 784 KB]

AC43-14, Rev 6, Standard Design Changes: Acceptable Technical Data has been revised and is attached for feedback . This is Revision 6 of this AC. Among other minor changes to standardise the format and terminology, Revision 6 amends Appendix 6 to include dual NAV/COM devices, and adds the following new appendices:

  • Appendix 15: Antenna installations
  • Appendix 16: Installation of replacement LED lights
  • Appendix 17: Installation of supplemental electronic carbon monoxide (CO) detectors
  • Appendix 18: Installation of Angle of Attack systems for awareness only
  • Appendix 19: Installation of ADS-B devices for awareness only

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 Wednesday 20 October 2021.

We're also looking for your feedback on how clear and useful our ACs are to you. When you view any AC page, a small prompt will appear asking you for feedback. We'd appreciate hearing what you think.


AC103-1 Revision 4 - Microlight Aircraft Operating Rules [PDF 335 KB]

AC103-1, Microlight Aircraft Operating Rules, has been revised, for the first time since November 2012. Revision 4 adds additional information relating to the delegation of microlight inspection and assessments after incorporation of a major modification, and reference to the process of operating engines beyond the manufacturer’s time between overhauls (TBO). We have also taken the opportunity to add a Version History.

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 Thursday 30 September 2021.


AC66-1 Revision 4 - Aircraft Maintenance Engineer Licence – General [PDF 585 KB]

Part 66L Website simplified Rating Designations to go with AC66-1 Rev 4 consult [PDF 497 KB]

Revision 4 of this AC has been drafted and is here for feedback. Revision 4:

  • Adds definitions of Avionics and Integrated Cockpit/ Flightdeck.
  • Updates competency standards for maintenance on aircraft principally constructed of fibreglass reinforced plastic (FRP) and ratings for engineers in avionics categories.
  • Adds notes on appropriate training and type ratings course for avionics related work, and updates training requirements for retrofitted complex avionics systems.
  • Clarifies eligibility requirements for a Certificate of Maintenance Approval (MA) and MA renewal applications.

A copy of the PDF of rating designations is also included with this draft. These designations are part of the information related to the updated AC, so this has been included for easy reference.

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 Tuesday 21 September 2021.

Advisory circulars closed for comment

AC43-1, Revision 5.1, Aircraft Maintenance [PDF 410 KB]

There has been a minor amendment to this AC. Incorrect references were discovered at para 2.6 to Appendix G of the Federal Aviation Regulations (FARs), not Appendices A and H: these have been corrected in Revision 5.1. CAA thanks the participant who brought this material to our attention.

Comments closed 1 September 2021


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).

Comments closed 30 August 2021


AC61-17 Revision 13 - Pilot Licences and Ratings—Instrument Rating [PDF 721 KB]

There has been a minor amendment to this AC. The marked-up version of Revision 13 is attached. Revision 13 deletes an item in the syllabus for IR Navigation which is no longer relevant, under section 54.22.24 With regard to uncharted routes (found on page 28), and adds a Version History.

CAA thanks the participants who brought this material to our attention. CAA expects to publish the new Revision in a few weeks. If you have any questions, please contact us here by Friday 20th August.

The next Revision of this AC will be a full revision of the theory and flight test syllabi, expected towards the beginning of 2022.

Comments closed 20 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.

Comments closed 9 August 2021


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