WALLARAH near Warnervale has emerged as a shock possibility as the site of Sydney's second international airport.
The Wyong Shire suburb has been named as one of the five best suited airport locations in a federal and state government report.
The report, titled the Joint Study on Aviation Capacity for the Sydney Region was overseen by an independent steering committee of government and industry experts.
It considered the short-, medium- and long-term aviation infrastructure needs of the Sydney region.
It was recently presented to the Australian and NSW governments after a two-year study which considered 34 potential airport sites.
The report then identified 18 localities for further assessment from which five sites, including Wallarah, were shortlisted.
The five sites were Wilberforce, Badgerys Creek-Luddenham, Silverdale, Wilton and Wallarah.
Regional manager of the Central Coast Business Chamber, Daniel Farmer, said major infrastructure improvements, especially involving transport, would be required if an airport were located at Wallarah.
"Issues would also arise of concern to the community including likely flight paths and noise problems," he said.
The shortlisting is likely to stir shire residents who, in the 1990s, fought a bitter legal battle to prevent Warnervale Airport from being upgraded for larger aircraft.
The report said sites were shortlisted on the basis of their closeness to demand, site suitability, aviation development capacity, conflicts with existing airports, flight paths, environmental impacts and closeness to growth centres.
Badgerys Creek was named the best site for the development of a supplementary airport but Transport Minister Anthony Albanese ruled out this option and said the government would instead start planning for the second favoured airport site at Wilton, which is 27 kilometres south-west of Campbelltown.
Wilton is susceptible to fog, aircraft would fly over northern suburbs of Wollongong, and its residents have raised environmental issues, citing its closeness to important water catchments.
The report said a Type 1 airport at Wilberforce would be likely to require closure of RAAF Base Richmond.
A Type 1 airport at Somersby would be subject to aircraft interaction with Sydney (Kingsford-Smith) Airport.
If no additional airport capacity was made available demand would exceed capacity by 54 million passenger movements a year by 2060, the report said.
Wallarah was identified as being suitable for a Type 1 full-service airport serving all market segments and capable of handling a future parallel runway layout.
The airport is expected to provide 100,000 jobs.
The report said: "Although Wallarah has some major shortcomings which would need to be addressed, of the Central Coast sites, it is considered to be more suitable for both a Type 3 and a maximum Type 1 airport."