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Project MS 08/20 - Amendment of CAO 100.5 to include mandatory maintenance requirements currently promulgated in Australian unique ADs

Topic code: 
Maintenance/Maintenance personnel
Project status: 

Closure notes

Project closed 11 November 2013.

Project cancelled 8/11/2013. Since this project was raised a number of ancillary activities have occurred that had the effect of significantly altering the original scope. To consolidate the work done previously and incorporate additional material, MS 08/20 is cancelled and has been replaced with project MS 14/06, with a revised terms of reference.


Under the review of Australian unique ADs, a number of ADs covering maintenance requirements have been identified that do not satisfy the requirements for issuing of an AD under CASR Part 39. The requirements in these ADs should be included in the regulations, or a Civil Aviation Order (CAO) if mandatory, or in advisory materials for guidance information or acceptable means of compliance.

Section 100.5 of CAO 100.5 provides the general requirements in respect of maintenance of all Australian aircraft. Paragraph 9 deals with replacement of time-lifed components, and requires the holder of the certificate of registration for an Australian aircraft to comply with the requirement specified in the Airworthiness Limitation Section of the maintenance manual of the aircraft. This does not consider airworthiness life limitations issued in other forms and made mandatory by the national aviation authority of the type certificate holder. Subsequently CASA has issued a number of ADs dealing with airworthiness life limitations that are not covered by this regulation This project will amend Paragraph 9 of CAO 100.5 to make mandatory all airworthiness life limitations required for type certification, and include in CAO 100.5 the mandatory maintenance requirements currently promulgated in Australian unique ADs.

The ADs identified for review have been amended and now include the following for possible incorporation into CAO 100.5:

Project Objective

The objective of the project is to adopt a flexible, outcome-based approach to the mandatory airworthiness requirements currently contained in maintenance ADs.

The project proposes to:

  • identify and examine the Australian unique maintenance type ADs and establish the mandatory requirements necessary to ensure aircraft safety.
  • develop legislation for CAO 100.5 that adopts the mandatory requirements in these ADs
  • amend paragraph 9 of CAO100.5 to cover all mandatory airworthiness limitations
  • develop supporting advisory material
  • implement the CAO 100.5 and cancel the Australian unique maintenance ADs

CASA’s objective is to improve the present situation by cancelling maintenance type ADs and transfer the necessary requirements to CAO 100.5. This will be an interim measure until the suite of maintenance regulations is fully implemented.

Rules affected

CAO 100.5

Project Status

This project was approved by Dinh Nguyen, A/g GGM AEG on 3 November 2008

Project management

Project Leader/s: Charles Lenarcic

Project Sponsor/s: Peter Boyd Executive Manager Standards Division

Standards Officer/s: Mike Broom