Lighting Aerodrome 21

21.22 VASI. Standard Visual Approach Slope Indicator. This consists of 2 sets of 3 lights positioned as wing bars. Each set of lights is designed so that the lights appear as either white or red, depending on the angle at which the lights are viewed. When the pilot is approaching the lights on the glide slope the first set of lights appears white and the second set appears red. When both sets appear white, the pilot is flying too high, and when both appear red the approach is too low.

VASIs

Figure 21.9 VASIs

Runway Lighting

21.23 Runway Edge Lights. Runway edge lights are provided for a runway intended for use at night or for a precision approach runway intended for use by day or night, and should be provided on a runway intended for take-off with an operating minimum below an RVR of the order of 800 m by day. Runway edge lights are placed along the full length of the runway in two parallel rows equidistant from the centre line. The lights shall be uniformly spaced. At intersections of runways, lights may be spaced irregularly or omitted, provided that adequate guidance remains available to the pilot. Runway edge lights are fixed, variable intensity white showing in the direction from which approaches are made. In the case of a displaced threshold, the lights between the beginning of the runway and the displaced threshold show red in the approach direction. A caution zone may be established over the last 600 m (or 1/3 of the runway whichever is least) where the lights are yellow. When the runway edge lights are intended to provide circling guidance, they shall show all round (omni-directional).

21.24Runway Threshold and Wing Bar Lights. Runway threshold lights are provided for a runway equipped with runway edge lights (except on a non-instrument or non-precision approach runway where the threshold is displaced and wing bar lights are provided). When the threshold is at the extremity of a runway, the threshold lights are placed in a row at right angles to the runway axis as near to the extremity of the runway as possible. For a displaced threshold, the lights are in the form of a barrette (wing bar) either side of the displaced threshold. Runway threshold and wing bar lights are to be fixed, unidirectional lights showing green in the direction of approach to the runway.

21.25Runway Threshold Identification Lights. Used at the threshold of a non-precision runway when additional threshold conspicuity is necessary or where the threshold is permanently displaced. They are flashing white lights unidirectional in the direction of the approach to the runway.

21.26Runway End Lights. Runway end lights are provided for a runway equipped with runway edge lights. Runway end lights are fixed, unidirectional lights showing red in the direction of the runway. Runway end lights are placed in a line at right angles to the runway axis as near to the end of the runway as possible, and should consist of at least six lights. The lights should be either equally spaced between the rows of runway edge lights, or symmetrically disposed about the runway centre line.

21.27Runway Centre Line Lights. Runway centre line lights are provided on Cat II/III precision approach runways. They should be provided on a Cat I precision approach runway where the width between the runway edge lights is greater than 50 m. Runway centre line lights are to be provided on a runway intended to be used for take-off with an operating minimum below an RVR of the order of 400 m. Runway centre line lights are fixed, variable intensity white. Over the last 900 m from the runway end, the lights show alternate red and white from 900 m to 300 m from the runway end; and all red from 300 m to the runway end.

21.28Runway Touchdown Zone Lights. Touchdown zone lights are provided in the touchdown zone of a Cat II/III precision approach runway. Touchdown zone lights extend from the threshold for a distance of 900 m where the runway is 1800 m or more in length. The lights are arranged in the form of strips either side of the centre line, the width of the strips is to be the same width as the touchdown zone markings. Touchdown zone lights are fixed, variable intensity, unidirectional showing white.

21.29Stopway Lights. Stopway lights are provided for a stopway intended for use at night with the lights placed along the full length of the stopway. Stopway lights shall be fixed, variable intensity, unidirectional lights showing red in the direction of the runway.

21.30Runway Lead-in Lights. Runway lead-in lights provide visual guidance along a specific approach path to aircraft onto where the runway approach lighting is in view. The system may be curved, straight or a combination of both. They consist of groups of at least 3 flashing white lights and, where practical, each group should flash in sequence towards the runway.

21.31Circling Guidance Lights. Circling guidance lights are provided when existing approach and runway lighting do not permit identification of the runway to an aircraft undertaking a circling approach to land. They may be fixed or flashing white.

Taxiway Lighting

21.32Application. Taxiway lighting provides pilots with guidance and information during the taxi to and from the runway. It consists of centre line lights, edge lights, guard lights, and stop lights at holding points.

21.33Taxiway Edge Lighting. Taxiway edge lighting is provided along the edges of holding bays, de/anti-icing facilities, aprons etc. It is intended for use at night on taxiways not provided with taxiway centre line lighting. If, however, sufficient alternative illumination is available (e.g. stadium lighting) then the edge lights may be dispensed with. Where a runway forms part of a standard taxi route intended for use at night and no taxiway centre line lighting exists, edge lights are to be provided. Taxiway edge lights are fixed, variable intensity omni-directional blue.

Aerodrome Lighting 21