Long-awaited preliminary flight paths for Sydney's new multi-billion-dollar airport have been released, nearly five years after construction of the facility began in the city's west.

An interactive online tool allowing residents to search an address and view the proposed flight paths is now available.

The website reveals expected aircraft noise in decibels, as well as the forecast altitude and number of flights in a particular location.

The $5.3 billion Western Sydney International Airport in Badgerys Creek will be the first in New South Wales with no curfew, with flights taking off and landing 24 hours a day, seven days a week.

The proposed flight paths show wind conditions will determine which of two main runway directions — known as Runway 05 and Runway 23 — will be used at any time during the day and evening.

The map below shows the locations that will be most affected by aircraft noise.

A noise level of 70 decibels is considered the benchmark for aircraft noise since it is enough to disturb a conversation indoors.

Luddenham, Badgerys Creek and Erskine Park are all predicted to experience flights above 70 decibels during the day.

Further afield, Springwood, Rossmore and Parramatta, would experience some flights, but at levels well below 70 decibels.

Erskine Park will be one of the worst affected suburbs by aircraft noise when Runway 05 is used.

In 2033, residents in Erskine Park are predicted to experience 20 to 49 flights exceeding 70 decibels over 24 hours.

When Runway 23 is used, residents around Greendale will be most affected — they are predicted to experience 20 to 49 flights exceeding 70 decibels over 24 hours.

By 2033 Greendale residents will hear 10 to 19 flights per night which exceed 60 decibels, which is a level that disturbs sleep.

The map below shows which areas will be most affected by aircraft noise at night.

A noise level of 60 decibels and above is considered the benchmark for when sleep would be disturbed.

Suburbs next to the airport including Greendale and Luddenham are predicted to experience these noise levels at least 10 to 19 times a night.

Further afield in St Marys and Marsden Park these noise levels will be experienced two to four times a night.

Residents in Liverpool and Kellyville are expected to hear the occasional flight at 42 decibels during the night, well below the limit to disturb sleep.

When Runway 05 direction is used, all aircraft will arrive from the south-west and depart to the north-east, while Runway 23 direction will see all planes arriving from the north-east and departing to the south-west.

A third runway operation plan, which can be used at night when air traffic demand is lower, is designed to minimise the impact of noise on the most heavily populated areas of Western Sydney.

The government said night flight paths were designed to take advantage of the increased airspace resulting from reduced overnight flights at Sydney and Bankstown airports.

Federal Transport Minister Catherine King said the new online tool provided "additional transparency" to the community, ahead of the airport's scheduled opening in late 2026.

"The preliminary flight paths were developed according to Airspace Design Principles that reflect community feedback from the 'proof-of-concept' flight paths released in 2015," she said.

"These principles include minimising flights over residential areas and reducing the impact on the community of aircraft operations at night."

Member of the Residents Against Western Sydney Airport (RAWSA) community group Peter Dollin said the release of preliminary flight paths has been a long time coming.

Mr Dollin has lived in Blaxland for almost four decades and is most concerned about the potential impacts of aircraft noise in his area.

"There's an absolute inequality going on here between eastern Sydney and Western Sydney," he said.

"Sydney Airport has the benefit of a curfew, there'll be no curfew for this airport."

Community information sessions will be held across Western Sydney in the coming months, where locals will be able to speak with the flight path design team.

A draft Environmental Impact Statement (EIS) that will look into the noise and environmental impacts of the proposed flight paths will also be released later this year for public feedback.

Minister King said it would include a draft "noise insulation" and "property acquisition policy".

"This [community] feedback will be considered as we finalise the flight path design," she said.

Construction of the airport is past the halfway mark.

The airport will initially have capacity for up to 10 million passengers and around 81,000 air traffic movements a year by 2033.

Earlier this month, Qantas and Jetstar became the first airlines to sign a deal with the airport.

The agreement will see five Qantas and 10 Jetstar aircraft operating at the Badgerys Creek site within its first year of operation.