CASA publishes feedback on draft plume rise Advisory Circular

Industrial exhaust plumes that are discharged vertically via chimneys or stacks may cause turbulence that is invisible to pilots but sufficient to adversely affect the safe operation of aircraft.

Katestone first assessed the potential impact of plumes on aircraft safety while preparing the Environmental Impact Statement for Oakey Power Station in late 1996. The situation was sensitive due to the power station being an open-cycle gas turbine with significant exhaust velocity and temperature in close proximity to the runway of an Air Force training aerodrome.

Australia’s Civil Aviation Safety Authority (CASA) recently published stakeholder feedback on its draft plume rise Advisory Circular (AC) (https://consultation.casa.gov.au/regulatory-program/draft-ac-139-e-02-v1-0/). One of CASA’s key functions is to provide guidance on how to manage Australian airspace to ensure safe operation of aircraft. 

CASA’s revised AC has adopted the MITRE Exhaust Plume Analyzer (MITRE EPA) Software that was developed for the United States Federal Aviation Administration. The revised AC also clarifies CASA’s role in the assessment process alongside Land Use Planning Authorities. 

During the consultation, CASA received 35 responses. Thirty-four respondents supported the proposal, with nine respondents recommending changes of a relatively minor nature to the proposal.  The common issues, questions or suggestions were around the ability of CASA to:

• influence the decision of Land Use Planning Authorities who are decision makers on proposals for facilities which emit plumes
• provide timely assessments
• assess impacts of light turbulence.

Katestone continues to provide expert modelling and advice on exhaust plume impacts for planning and development.

Contact Simon Welchman, 07 3369 3699, for further information.