What is docking guidance?
A display on the stand that shows the pilot the centreline and the stopping position while taxiing in to a nose-in gate.
A visual docking guidance system (VDGS) guides the pilot of an aircraft taxiing in to a nose-in stand. It does two jobs: it shows whether the aircraft is on the stand centreline (azimuth guidance), and it shows where the aircraft must stop.
Older systems use separate units for the two jobs, such as AGNIS for azimuth and a parallax aircraft parking aid (PAPA) for the stop. Modern systems use one display, fed by sensors that detect the aircraft as it enters the stand. On a typical display a flashing arrow shows which way to correct, a yellow centreline indicator shows the aircraft is aligned, a closing-rate bar shows how far it still has to go, and a red STOP marks the stopping position. Symbols and colours vary a little between manufacturers. Many systems can also check the aircraft type, so that the stopping position matches the aircraft.
The display is placed ahead of the aircraft, on the stand centreline, where the pilot can see it clearly. Stopping the aircraft in the same place every time lets the boarding bridge and the ground equipment reach the doors, and keeps the aircraft clear of the buildings and other stands. Docking guidance is a visual aid for the pilot, and the procedures around it are set by the airport operator.
Frequently Asked Questions
Q1What is a visual docking guidance system?
A visual docking guidance system, or VDGS, is a display at an aircraft stand that guides the pilot while taxiing in. It shows whether the aircraft is on the stand centreline and where to stop, so the aircraft ends up in the right place at the gate.
Q2What does the pilot see on a docking guidance display?
The pilot sees a flashing arrow showing which way to steer toward the centreline, a centreline indicator when the aircraft is aligned, a closing-rate bar or distance readout as it nears the stop, and a clear red STOP signal at the stopping position. Symbols and colours vary slightly between systems.
Q3How does the system know where the aircraft is?
Modern systems use sensors, such as laser scanners, radar or cameras, to detect the aircraft as it enters the stand. They work out its position, and many can also identify the aircraft type, so the stopping position and the guidance match that aircraft.
Q4Is a marshaller still needed?
That depends on the airport's procedures. The system does the job of guiding the aircraft, but many airports keep ground staff to check that the stand is clear and to act as a back-up. Take the rules from the airport operator.
Q5Is docking guidance part of the airfield ground lighting?
It is part of the stand equipment rather than the runway or taxiway lighting. It is closely related to the apron and stand lighting, and it is a visual aid for the pilot, like the other guidance systems in this section.
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