The purpose of runway guard lights is to warn pilots, and drivers of vehicles when they are operating on taxiways,
that they are about to enter an active runway. There are two standard configurations of runway guard lights as illustrated in Figure.As part of runway incursion prevention measures, runway guard lights, Configuration "A" or "B", are provided at each taxiway/runway intersection where runway incursion hot spots have been
identified, and used under all weather conditions during day and night..Configuration "B" runway guard lights are not collocated with a stop bar.Runway guard lights, Configuration 'A', are located at each side of the taxiway at a distance from centre line not less than for a take-off runway.
Runway guard lights, Configuration "B', are located across the taxiway at a distance from centre line not less than for a take-off runway.Runway guard lights, Configuration "A", consists of two pairs of yellow lights.
Runway guard lights,Configuration "B", consists of yellow lights spaced at intervals of 3m across the taxiway. The light beam is unidirectional and aligned so as to be visible to the pilot of an aeroplane taxiing to the holding position.For Configuration "B", adjacent lights are alternately illuminated in unison.The lights are illuminated between 30 and 60 cycles per minute and the light suppression and illumination periods areequal and opposite in each light.
The lights in each unit of Configuration "A" is illuminated alternately.
Intermediate Holding Position Lights
Except where a stop bar has been installed, intermediate holding position lights are provided at an intermediate holding position intended for use in runway visual range conditions less than a value of 350 m.These lights are located along the intermediate holding position marking at a distance of 0.3 m prior to the marking.Intermediate holding position lights consist of three fixed unidirectional lights showing yellow in the direction of approach to the intermediate holding position. The lights are disposed symmetrically about and at right angle to the taxiway centre line, with individual lights spaced 1.5 m apart.
A stop bar is provided at every runway holding position serving a runway when it is intended that the runway will be used in runway visual range conditions less than a value of 350m.These are located across the taxiway at the point where it is desired that traffic stops. Where the additional lights are provided, these lights are located not less than 3m from the taxiway edge. Stop bars consist of lights spaced at intervals of not more than 3 m across the taxiway, showing red in the intended direction(s) of approach to the intersection or runway-holding position. Stop bars installed at a runway-holding position are unidirectional and show red in the direction of approach to the runway. Stop bars located across entrance taxiways are selectively switchable which means when a stop bar is illuminated, any taxiway centre line lights installed beyond the stop bar gets extinguished for a distance of at least 90 m and vice versa.
Runway turn pad lights are provided for continuous guidance on a runway turn pad intended for use in runway visual range conditions less than a value of 350 m, to enable an aeroplane to complete a 180-degree turn and align with the runway centre line.These lights are normally located on the runway turn pad marking, except that they may be offset by not more than 30 cm where it is not practicable to locate them on the marking.Runway turn pad lights on a straight section of the runway turn pad marking are spaced at longitudinal intervals not more than 15 m. Runway turn pad lights on a curved section of the runway turn pad marking have a spacing not exceeding 7.5 m.
These are unidirectional fixed lights showing green with beam dimensions such that the light is visible only from aeroplanes on or approaching the runway turn pad.
A Ram Air Turbine (RAT) is a small turbine that is installed in an aircraft which is used as an alternate or emergency hydraulic or electrical power source. The RAT generates power from the airstream based on the speed of the aircraft and is connected to an electrical generator or to a hydraulic pump.
In general, modern aircraft only utilize the RAT in emergency in the following cases:
1.In the event of loss of hydraulic systems.
2.In event of loss of primary electrical generation.
In these cases the RAT will power vital systems such as flight controls or flight-critical instrumentation, navigation and communication equipment. Some RATs produce only hydraulic power which in turn is used to power an electrical generator.
Under normal conditions, the RAT is stowed in a compartment in the fuselage or wing. It can be deployed manually when required or, in some installations, will deploy automatically following a complete loss of AC power.
Note: In the interval between power loss and RAT deployment, aircraft batteries are used to power essential instrumentation.
Taxiway Exit Centre Line Lights
Taxiway centre line lights on an exit taxiway are fixed bidirectional lights. Alternate taxiway centre line lights show green and yellow from their beginning near the runway centre line to the perimeter of the ILS/MLS critical/sensitive area or the lower edge of the inner transitional surface, whichever is farthest from the runway; and thereafter all lights show green. The first light on the exit centre line always show green and the light nearest to the perimeter always show yellow. Taxiway centre line lights on a rapid exit taxiway commences at a point at least 60m before the beginning of the taxiway centre line curve and continue beyond the end of the curve to a point on the centre line of the taxiway where an aeroplane can be expected to reach normal taxiing speed. The lights on that portion parallel to the runway centre line are always kept at least 60cm from any row of runway centre line lights.The lights are spaced at longitudinal intervals of not more than 15m.Taxiway centre line lights on exit taxiways other than rapid exit taxiways commences at the point where the taxiway centre line marking begins to curve from the runway centre line, and follow the curved taxiway centre line marking at least to the point where the marking leaves the runway. The first light be at least 60cm from any row of runway centre line lights.The lights are spaced at longitudinal intervals of not more than 7.5m
Taxiway edge lights are fixed lights showing blue.These lights are provided at the edges of a runway turn pad, holding bay, de-icing/anti-icing facility, apron, etc., intended for use at night and on a taxiway not provided with taxiway centre line lights and intended for use at night, except that taxiway edge lights need not be provided where, considering the nature of the operations, adequate guidance can be achieved by surface illumination or other means.Taxiway edge lights on a straight section of a taxiway, a runway forming part of a standard taxi-route, holding bay and apron should be spaced at uniform longitudinal intervals of not more than 60m. The lights on a curve are spaced at intervals less than 60m so that a clear indication of the curve is provided.The lights may be located as near as practicable to the edges of the taxiway, runway turn pad, holding bay, de-icing/anti-icing facility, apron or runway, etc., or outside the edges at a distance of not more than 3m.These lights on a runway turn pad are spaced at uniform longitudinal intervals of not more than 30m.
Taxiway Centre Line Lights
Taxiway centre line lights are provided on a runway forming part of a standard taxi-route and intended for taxiing in runway visual range conditions less than a value of 350 m, except that these lights need not be provided where the traffic density is light and taxiway edge lights and centre line marking provide adequate guidance. These are fixed lights showing green with beam dimensions such that the light is visible only from aeroplanes on or in the vicinity of the taxiway.Thses are normally located on the taxiway centre line marking, except that they may be offset by not more than 30cm where it is not practicable to locate them on the marking.Taxiway centre line lights on a straight section of a taxiway are spaced at longitudinal intervals of not more than 30m.
Stopway lights are fixed unidirectional lights showing red in the direction of the runway.Stopway lights are provided for a stopway intended for use at night.These are placed along the full length of the stopway and are in two parallel rows that are equidistant from the centre line and coincident with the rows of the runway edge lights.
Stop way lights are provided across the end of a stopway on a line at right angles to the stopway axis as near to the end of the stopway as possible and, in any case, not more than 3 m outside the end.
Rapid Exit Taxiway Indicator Lights (RETILs)
The purpose of RETILs is to provide pilots with distance-to-go information to the nearest rapid exit taxiway on the runway, to enhance situational awareness in low visibility conditions and enable pilots to apply braking action for more efficient roll-out and runway exit speeds. These are provided on a runway intended for use in runway visual range conditions less than a value of 350 m and/or where the traffic density is heavy.A set of rapid exit taxiway indicator lights are located on the runway on the same side of the runway centre line as the associated rapid exit taxiway, in the configuration shown in Figure subsequently. In each set, the lights are located 2 m apart and the light nearest to the runway centre line are displaced 2 m from the runway centre line.These are fixed unidirectional yellow lights, aligned so as to be visible to the pilot of a landing aeroplane in the direction of approach to the runway.