IT'S vital that the federal government finalises Badgerys Creek airport plans now if it hopes to mitigate the impact of noise on future residents of south-west growth centre suburbs, an expert says.
Acoustical consultant Robert Wilkinson, principal at Wilkinson Murray, said the exact positioning of the airport and the orientation of the runways would have a major impact on the noise experienced in surrounding residential suburbs.
"It's unclear what the exact plans will be at the moment because the last study was done in the 1990s and there were three options which came out of that," Dr Wilkinson said.
"They would have to produce some different plans now because a lot has changed; aircraft have got quieter.
"The modern A380 is three decibels quieter than a 747.
"In real terms that means if you weren't paying attention and something became three decibels quieter you'd be able to notice the difference.
"A 10-decibel difference is when something is half as loud. But it seems the total sound impact would be far less than that of the existing Sydney airport because there are still fewer people living in that area."
He said it was obvious a decision on the airport needed to be made quickly now even though the plan had been debated for more than 30 years. "Once the airport plans are in place the residential-housing development could be factored in around that to minimise the impact.
"But the studies need to be started now because they'll take about two years to complete.
"Also, I think it's fairly clear Sydney airport is not functioning optimally now and won't be sufficient in the future."
He said Badgerys Creek airport would need to run without a curfew and with fewer aircraft operation restrictions than those at Mascot.
"The planning assumes it will be a 24-hour airport and it would free up freight operations around the clock.
"But there are Australian Noise Exposure Forecasts which determine where it's acceptable to build residential housing and where it's not.
"Once an airport is planned we could avoid building housing in the areas with the highest ANEF levels.
"That planning wouldn't just depend on the distance from the airport in kilometres but the positioning of runways, flightpaths, number of aircraft on each flightpath and other factors."
Wilkinson Murray may be involved in the airport's environmental impact study.