Apply for exclusion or alternate means of compliance to Airworthiness Directives

We issue Airworthiness Directives (ADs) to address an unsafe condition in aviation products.

Operators can:

  • propose an alternative means of correcting the unsafe condition
  • apply for an exclusion from the AD if the unsafe condition can't develop on their aircraft.

An Alternative Means of Compliance (AMOC) or exclusion can apply either a part of, or the whole AD.

We will make a decision based on engineering practices. We will only approve alternatives that achieve the same level of safety as intended by the AD.

How to apply for an exclusion or AMOC

To apply for an exclusion/AMOC, you need to:

  1. Complete Form 90 Alternate means of compliance/exclusion from Airworthiness Directive or exclusion (you can get a copy from your local CASA office).
  2. Send the completed form and any supporting documentation to your local office.
  3. Wait for a cost estimate from us.
  4. Pay the estimated amount if you wish to proceed.

You must pay a processing and consideration fee, which is the estimated time multiplied by an hourly rate.

On receiving the application, we will estimate the number of hours needed to assess the application and provide a written cost estimate.

Once you have paid the fee, we will assess the application and make a decision. The payment is for processing and considering the application and does not guarantee an outcome.

Supporting documentation

You will need to provide engineering justification that demonstrates how the exclusion or AMOC will:

  • address the unsafe condition
  • provide the same level of safety intended by the AD
  • ensure the unsafe condition no longer exists and cannot develop again.

We recommend you also provide:

  • engineering justification endorsed by a CASR 21M authorised person
  • a statement of no technical objection from the manufacturer or the State of Design NAA.

Further information

To find out more, see AC 39-01 v4.3 Airworthiness Directives.

Last updated:
6 Dec 2021
Online version available at:
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