It runs south from platform 23 at Central station across a viaduct to the tunnel portal beneath Prince Alfred Park near Chalmers Street.

From Mascot, the line roughly follows O'Riordan Street before turning sharply to the west once underneath Sydney Airport.

The two new stations which were built for the airport's International and Domestic Terminals, feature larger lifts and wider ticket barriers to cater for passengers with baggage.

[9] Construction began on 12 February 1995 with a view to improving facilities for air travellers ahead of the 2000 Summer Olympics.

[12] While the use of a Tunnel boring machine relieved the need for large numbers of workers at increased pressure, a caisson system is formed at the cutting head.

Local (all stations) trains generally were timetabled to run from East Hills via the airport, peak hour express trains from Campbelltown run along the original route via Sydenham, taking the express tracks between Kingsgrove and Wolli Creek Junction.

Less than a year after the line opened, the State Rail Authority stated that "patronage has been lower than expected to date", but they remained optimistic, believing "that as airport users become more familiar with this facility and the ingrained habits of many years gradually alter, patronage will continue to increase.

[16] Together with the Cross City Tunnel, the Airport Link served to dampen government and business enthusiasm for further public private partnerships in transport in New South Wales.

[20][21] In 2013, Westpac's 49.9% stake was purchased by Universities Superannuation Scheme (USS), who then took control of the Airport Link Company.

[3] Following the removal of the access fee, patronage at Green Square and Mascot increased by 70 percent between March and June 2011 as a result of the reduced fares.

[28] By 2018, Green Square and Mascot stations were experiencing overcrowding at peak times due to significant increases in patronage.

This contrasts with Brisbane's AirTrain line which is primarily serviced by Queensland Rail's IMU and NGR fleets, both of which make provision for luggage carrying passengers, as well as offering additional passenger comforts such as high backed seats, free Wi-Fi and toilets.