Stand guidance systems

A stand guidance system is a system which gives information to a pilot attempting to park his aircraft at an airport stand, usually via visual methods, leading to the term "Visual Docking Guidance System" (VGDS) and also "A-VGDS" (the A standing for advanced) This allows them to remain free of obstructions and ensures that jetways can reach the aircraft.

AGNIS VGDS

Azimuth Guidance for Nose-In Stand is one of the most popular forms of stand guidance. It consists of two coloured lights mounted side by side.

If the pilot is on the stand centreline they will see two green lights. If they are off centreline, one of the lights will appear red and the pilot then steers towards the green one. AGNIS alone provides only azimuth guidance, it does not inform pilots when they should stop.

PAPA

Parallax Aircraft Parking Aid is frequently combined with the AGNIS system to inform flightcrews when to stop. The device features no electronics or moving parts; it consists simply of a large black box (usually with some sides missing) with a large rectangular slot cut in to the front. Inside the box is a white stick, which appears to move from side of the slot to the other, although it is in fact fixed and the effect is merely due to perspective.

Above and/or below this slot will be markings in white or yellow, indicating where different types of plane should stop.

top light

This is a simple two phase traffic light with red and green lights, mounted to the side of the AGNIS lights.

Mirror

Used in combination with AGNIS at stands which can only accept smaller airliners, it features one or two mirrors, allowing the flightcrew to see ground markings in relation to their nose wheel, when it is within the area they need to stop. Typically two mirrors are used, angled differently to suit the various heights of cockpits from the ground.

A-VGDS

afe gate

Safegate is the most popular stand guidance systems after AGNIS and is seen at major airports throughout the world, making it the most popular A-VDGS in the world.

The green lights on the left and right of the display will begin to appear, from bottom to top, as the aircraft gets closer to the stop line. The green centreline on the display moves smoothly left and right to accurately indicate how away from the centreline an aircraft is.

Systems of this type will usually have emergency stop buttons located both on the stand and in the jetway/gate area, which causes the STOP display to appear immediately.

APIS

The Aircraft Positioning and Information System shows azimuth information on the left side of its display. A series of parallel and black bars which kink at their midpoint. The bars will appear straight when the aircraft is on the centreline, and the angle of the kink will become more acute the further away an aircraft gets from the centreline.

Distance information is given by a bar on the right side of the display, which disappears from bottom to top as the aircraft gets closer to the stop point. Across the top of the display, text will initially display the aircraft type the system has identified, and will display "STOP" when aircraft reaches the stop point. It can also display "T.FAR" and "O.BLK".

afedock

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Marshaller

Marshallers use a variety of arm signals to indicate where aircraft are in relation to both the stop line and the centreline. Signals used by military marshallers can vary between countries, however those used at civil facilities are of an international standard.

ources

[http://www.gbairports.co.uk/ea2k/gateguide/gateguide.htm]