Consultation draft - proposed amendments to maintenance release and general provisions of Civil Aviation Order 100.5 (CD 1615MS)

Closed 29 Sep 2017

Opened 1 Sep 2017

Results updated 1 Mar 2018


In total, there were 6 respondents to the discussion paper. Of the respondents who made written submissions, 4 consented to having them made public and 2 requested their submissions be confidential.

Most responses received were from aircraft operators, with 1 respondent identifying as having no particular industry or organisation affiliation.

Key feedback and policy changes

Comments received covered the following aspects:

  • On-the-job training provisions for maintenance of composite aircraft should be removed from the CAO and any such training should only be provided by an approved training provider. CAO 100.5 needs to clarify what is meant by self-test function in relation to fuel quantity indication systems. CAO 100.5 should not apply to aircraft that use MSG-3 based maintenance programs.

CASA has amended the draft CAO 100.5 amendment instrument as a result of the feedback. In particular:

  • to address an under supply of available training, CASA will retain the provision for on the job training in composite maintenance. The amendments and supporting material provide appropriate controls and guidance material, based on the current industry standard, to ensure adequate training is provided by the applicable organisations.
  • CASA has expanded the wording to specify that a self-test function must establish that the fuel indication self-test system is performing within manufacturers published tolerances.
  • CASA has amended the draft CAO amendment instrument to give precedence to   manufacturer's maintenance programs and approved systems of maintenance that address all the aircraft's systems, in the event of conflict between the CAO and the maintenance programs or systems of maintenance.

Notice of final rulemaking

Civil Aviation Order 100.5 Amendment Instrument 2017 (No. 1) was made on 30 October 2017 and commenced on 1 November 2017. CASA informed industry of the instrument being made by notification to the consultation and rulemaking mailing list.

Future direction

CASA will monitor the effectiveness of the amended CAO 100.5 with a view to further revision if required based on industry feedback and safety outcomes.

Published responses

View submitted responses where consent has been given to publish the response.


In 2015, CASA identified a number of airworthiness directives (ADs)—that prescribed general maintenance requirements—that did not satisfy the requirements under Part 39 of the Civil Aviation Safety Regulations 1998 (CASR) for the issue of an AD . CASA published a consultation draft (CD 1423MS) proposing the transfer of the maintenance requirements to Civil Aviation Order (CAO) 100.5 and subsequently transferred these requirements through Civil Aviation Order 100.5 Amendment Instrument 2015 (No.1).

Subsequent feedback from industry has revealed a number of unintended consequences. CASA now proposes to amend CAO 100.5 to correct the matters raised in industry feedback, accommodate a number of policy developments, clarify some aspects of existing policy, and update the instructions for preparing, issuing and using the CASA maintenance release.

Why your views matter

CASA recognises the valuable contribution that community and industry consultation makes to the regulatory development process. This consultation draft sets out the proposed changes to CAO 100.5 and CAAP 43-01, and new guidance provided in CAAP 100.5-01.

A copy of the briefing paper is provided below. You can read it on this screen using the scroll bar or save it to your computer using the popup options. The draft CAO 100.5 amendment instrument and both CAAPs are provided in the 'related' section further down this page.

Please read the documents before providing your feedback in the online survey.

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What happens next

At the end of the response period for public comment, we will register and review each comment and submission received through the online response form, but will not acknowledge individual responses. We will consider the submissions to this Consultation Draft before making any change to the regulations or other legislative instrument.

We will make all submissions publicly available on the CASA website unless a respondent requests that their submission remain confidential. Information about how we consult and how to make a confidential submission is available on the CASA website.

When the CD submissions are published we will also publish a summary of consultation. The summary of consultation will summarise the feedback received, detail our plans for future policy, and outline any further consultation or planned rule making on this subject.

If we do change the rules, we will not publish an NFRM; information about the rule making will be available in the Explanatory Statement that is published with the final rule on the Federal Register of Legislation. You can subscribe to our consultation and rule making mailing list to be notified of future consultation or rule making on this subject.


  • Airworthiness organisations


  • Airworthiness / maintenance