The Civil Aviation Safety Authority has drawn criticism from AOPA Australia for approving an aviation impact assessment for the proposed Tallawarra B power station.
Last week, Energy Australia was granted planning approval for an open cycle gas turbine power station to be built in the circuit area of Shellharbour Airport after CASA accepted a gas plume velocity of 6.1 m/s at 700 feet as being safe.
Previously, AOPA Australia had calculated that a plume velocity of only 4.3 m/s would be needed to ensure the plume presented no danger to GA and recreational aircraft.
"AOPA Australia are deeply concerned that CASA have created a risk to the safety of aviation at Shellharbour Airport by their prime decision that a 6.1 m/s plume velocity at 700 feet AGL is an acceptable safety yardstick for the Tallawarra B project," AOPA CEO Ben Morgan said in a letter addressed to CASA CEO and Director of Aviation Safety Shane Carmody.
"AOPA Australia have presented CASA [with] calculations, using approved data from the Pilot Operating Handbook of the ubiquitous Cessna 172N, that show 4.3 m/s is the maximum critical plume velocity for any such assessment related to any plume within the circuit at Shellharbour Airport.
"Would you please explain how CASA concluded that a plume with a velocity of 6.1 m/s at 700 feet AGL within the circuit at Shellharbour Airport does not pose a risk to the safety of aviation?"
Morgan crticised CASA for approving the gas plume velocity based on what it says is a potential design and not the final design for the power station. Energy Australia put forward an engineering solution in the aviation impact assessment that was designed specifically to reduce the plume velocity.
Morgan said that AOPA was disappointed that CASA reviewed the assessment "behind closed doors, ignoring the input of the aviation community" and accused the regulator of then "wiping its hands" of the outcome.
Energy Australia plans to commission Tallawarra B in the summer of 2022-23.