[1] The control tower complex occupies a central position in the airport, to the north of the point at which General Holmes Drive goes under the main north–south runway.
[1] Sydney 5 control tower comprises a cable-stayed pre-cast concrete shaft with an external passenger lift to the north.
A spiral escape staircase sweeps around the concrete shaft, which is positioned just off-centre of the circular single-storey base building.
The design concept is described by architect Ken Woolley:[1][3]"The geometry of the design is based on an equilateral triangle or tri-star plan with a slim pre-cast central column in which services run, supporting a steel strutted and cantilevered platform and braced by post-tensioned steel rods to three points on the base building.
"The doughnut-shaped plan of the base building is broken to the north-east to accommodate an opening for a paved pathway, which leads to an entrance lobby at the south of a sheltered courtyard.
[1] The off-white segmental concrete shaft is 2.5m in diameter and 20m high, with a flat face to the north to which the lift is attached by steel fly-braces.
The cabin roof accommodates surface movement radar, warning lights and a crown of aerials and lightning conductors.
[1] The spiral staircase is a rectangular tube of 18 cranked facets in aluminium panels punctuated by small porthole windows.
A return flight of stairs inside a single-storey concrete cylinder provides access from ground level to the bottom of the spiral staircase.
Alterations to the base building since construction include the extension of the lobby (c. 1998), and modifications to the subdivision of the east wing to accommodate additional office space.
Toilets are to the west of the central lift lobby and circulation space, with staircases extending to the cabin above and the escape stair below.
[1] The floors are reinforced concrete, carpeted in the central lobby and stand-down areas; exposed in the air conditioning plant and equipment rooms.
Ceilings in the lobby and stand-down areas are lined with perforated metal acoustic panels with recessed vents and lighting.
The consoles use touch-screen technology of the type used in modern aircraft, giving controllers access to situational radar, communication and meteorological data displays.
[1] The ATC complex is largely intact as built, externally and internally, with the only significant modification being the extension of the curved entrance foyer to accommodate a larger reception area.
Its predecessors in the Australian context were either utilitarian structures based on standardised models (1950s- 1980s), or imposing but comparatively restrained forms consisting of slender concrete columns surmounted by amenities/services with cabins above (late-1960s to present).
It was the first Australian tower with a circular cabin, and first to be fitted with a peripheral console, an established format internationally and the preferred future form in Australia.
[1] Sydney 5 was also the first tower in Australia to employ computer screen-based technology for its control consoles, derived from the "fly-by-wire" concept used in modern aircraft.
[1] This Wikipedia article was originally based on Sydney Airport Air Traffic Control Tower, entry number 106116 in the Australian Heritage Database published by the Commonwealth of Australia 2018 under CC-BY 4.0 licence, accessed on 21 September 2018.