Illuminated Wind Indicator

An essential piece of equipment for all aerodromes is a Wi
nd Direction Indicator (WDI), universally known as the 'windsock'. At aerodromes approved for night flying, an Illuminated Wind Indicator (IWI) is required.

Australian regulations require the primary WDI to be white in colour. Any additional windsocks not intended to be illuminated at night are coloured yellow and any additional IWIs are coloured white or another colour that is clearly visible when illuminated.


The photo above, taken at Bendigo, Vic, in March 2005, shows a typical primary IWI. On top of the assembly are duplicated red hazard lights. Below that are duplicated spotlights, arranged to shine on the windsock, whatever its direction. The windsock itself is designed to swivel to indicate the direction of the wind, and to be fully extended at a certain wind speed - usually 15 knots.

The IWI stands in a 9 m diameter black circle outlined with a 1 m white border, so as to make locating it from the air easier. Six evenly-spaced white markers may be used in lieu of the border - click here for an example.

Standards require that runways served by a non-precision instrument approach (e.g. VOR, NDB) must have a windsock at the threshold of the runway, preferably 100 m upwind from the threshold. Nevertheless, aerodromes with runways less than 1200 m in length need only have one, centrally-located windsock.

(Photo: Phil Vabre/CAHS collection)

Back to the main Airports & Aerodromes index

If this page appears without a menu bar at top and left, click here