Draft AC 139-05 v3.0 - Changes to Plume Assessment

Closed 17 Aug 2018

Opened 3 Aug 2018


The purpose of this Advisory Circular (AC) is to provide:

  • A standard method of determining the critical velocity of a vertical exhaust plume so that the impact of a plume near aerodromes and away from aerodromes can be assessed in a consistent and reliable way.
  • Guidance to persons involved in the design, construction and operation of facilities with vertical exhaust plumes about the information required to assess the potential hazard from a plume to aircraft operations.
  • Guidance to proponents and stakeholders on the plume rise assessment process.

Closing date for comment

CASA will consider all comments received on the Draft AC 139-05 v3 - Changes to Plume Assessment. Comments should be submitted through the online response form by close of business 17 August 2018.

Why We Are Consulting

CASA recognises the valuable contribution that community and industry consultation makes to the regulatory development process.

This is the second revision of the AC relating to the conduct of plume rise assessments and replaces AC 139-5(1) issued in November 2012. It has been revised to include the use of the 6.1m/s benchmark velocity which has been included in the "Screening Tool".

A copy of the draft AC is provided below. You can read the document on this screen using the scroll bar or save it to your computer using the popup options.

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

On this page under the heading, "Related Documents” you will find a downloadable Word copy and PDF of this consultation. This is for ease of distribution and feedback within your organisation.   


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What Happens Next

At the end of the response period for public comment, we will review each comment and submission received through the online response form. 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 responses to the consultation, for which permission has been granted for publication are published, we will also publish a summary of consultation (SOC). The SOC will summarise feedback received, describe any intended changes and detail our plans for this Advisory Circular.

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  • Aerodrome operators
  • Engineers
  • Manufacturers


  • Airworthiness / maintenance