How does a VDGS recognise the aircraft type and check its profile?
The stop point is set for one type. Before the display can be trusted, the system has to be sure the aircraft rolling in is the one it expects.
A docking system does not only find an aircraft, it has to find the right one. The stopping position is different for each type, so the system holds an expected type for the stand and then verifies the measured profile against it before it trusts the guidance it is about to give.
1Why the type matters
Door positions, nose-gear positions and the pilot’s eye position all change from one type to another. A stop point that suits one aircraft would leave another short of the bridge or past it. That is why the expected type is shown on the display, so the crew can confirm it is theirs.
2Select, then measure
The expected type may come from the airport’s stand allocation or flight data, or be entered by the operator or ground staff, and some systems can also work out the type for themselves. Once the aircraft is captured, the sensor measures features such as the nose height and shape, engine positions, fuselage width and wingspan.
3Compare with the stored profile
Each type the stand serves has a stored profile in the system. The measured features are compared with it within a tolerance, so small differences are expected and only features that fall outside the band fail the check. Annex 14 expects docking guidance to be suitable for the aircraft types using the stand, but how a system recognises and checks the type is left to the manufacturer.
4What goes wrong
The wrong type selected gives the wrong stop point. A new type or variant that has not been loaded has no profile to match. Variants of one family can look alike, so a match may confirm the family but not the variant. Ground equipment in front of the aircraft can hide features. On a mismatch the system should alert, not carry on silently, and the stand’s procedures take over. The pilot stays responsible for a safe stop.
| Stage | What the system does | Result |
|---|---|---|
| Select | Takes the expected type for the stand | Type shown to the crew |
| Capture | Detects the aircraft entering the zone | Profile measurement starts |
| Measure | Reads nose, engine, width and span features | Measured profile |
| Compare | Checks the features against the stored profile within a tolerance | Match or mismatch |
| Match | Keeps steering and stopping guidance running | Stop point for that type |
| Mismatch | Raises an alert instead of silent guidance | Type check; procedures take over |
Frequently Asked Questions
Q1Why does a VDGS need to know the aircraft type?
The stopping position is different for each type, because door positions, nose-gear positions and the pilot's eye position differ. The system needs the right type so it can show the stop point for that aircraft, and so the aircraft ends up where the boarding bridge can reach it.
Q2Where does the system get the expected type from?
It depends on the system. The type may come from the airport's stand allocation or flight data, or be entered by the operator or ground staff, and some systems can also work out the type from the measured profile. Check the arrangement against the manufacturer's data and the airport operator's procedures.
Q3What does profile verification actually check?
The sensor measures features of the aircraft, such as nose height and shape, engine positions, fuselage width and wingspan, and compares them with the stored profile for the expected type, within a tolerance. Which features are used depends on the system.
Q4What happens if the profile does not match?
The system should alert rather than carry on as if nothing were wrong, for example by withholding the stop point or showing a message to check the type. The exact behaviour is set by the manufacturer and the airport, and the stand's procedures, such as a marshaller, take over.
Q5Can the system tell similar variants apart?
Not always. Variants of one aircraft family can share a nose and engine layout, so a check may confirm the family but not the exact variant. That is why the expected type is selected carefully and the stored profiles are kept in step with the aircraft types the airport serves.
Q6Who is responsible for a safe stop, the system or the pilot?
The docking system is an aid. The pilot remains responsible for docking safely and stops on any stop signal or instruction from the ground. The airport operator is responsible for keeping the type data and profiles correct.
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