The light units for the T-VASIS sytem have been produced in three distinct series. The photos on this page show typical lightboxes of Types B and C. Click here to see the earlier Type A style of light unit.
The photo above was taken abeam the touchdown point of Runway 14 at Bundaberg, Qld., in July 2003. The aircraft at the terminal is a Sunstate Airlines Canadair Dash 8. The unit is a typical Type C lightbox from the transverse part of the 'T'. The transverse lights remain visible at all times, unlike those from the 'stems' of the T which become visible only when the aircraft deviates above or below the correct visual glideslope. The lightboxes have different covers and internal fittings depending on their role and position within the system.
Although widely regarded as the best visual approach slope guidance system in the world, one of the disadvantages of T-VASIS is the cost of laying and maintaining pads so as to accurately level the lightboxes. The 'horns' visible at the near end of the box are pads for a levelling beam.
Above and below: Type B units at Melbourne/Tullamarine Airport Runway 09 in August 1972. The upper units are 'bar boxes' from the transverse array while the lower unit is from one of the vertical arrays. Note the different covers in each case, critical to cutting off the viewing angles of each light unit at precisely determined angles.
Above and below: Newer Type C lightboxes at Melbourne/Essendon on Runway 08, also photographed in August 1972. Once again, the upper units are the transverse array, while that below is a 'fly down' unit from the upper part of the stem of the 'T'.
Below: A 'fly up' unit from an unidentified array in August 1972.
(Photos: Top-Phil Vabre, rest-CAHS/Byron Sullivan collection)
Click here to read about the history of T-VASIS
Click here to read the Pilots' Notes on T-VASIS
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