Pearson International : Visual Docking Guidance System

[Philip Mew]

The last few times I have parked at CYYZ, more often than not I get a red arrow command to go left or to go right, even if the nosewheel is dead centre on the yellow line. If I follow the command and make the tiniest correction, usually this results in a command to turn in the opposite direction.

In a B777-300 with the nosewheel camera, I could see that I was definitely right on top of and centred on the yellow line. On a B777-200, I confirmed the same when I viewed the aircraft from the inside the terminal.

The B777 is a long airplane, especially the 300. Are the VDGS units at Pearson "fussier" than normal ? I have not observed this to be the case at other airports.

I don't ignore red commands for obvious reasons, but geez, either I am on the yellow line or I'm not.

Comments ?

[EEngr]

Any idea what make/model docking system they use? Or what technology?

[767-300ER]

Phil

I suspect that the issue isn't whether or not the nosewheel is on the centreline, the issue is whether the nosewheel is on the centreline and the fuselage is aligned with the lead-in line..

I have found that even being on one side of the line, the system might have me turn away from the lead-in line in order to get the aircraft centre-line aligned with the parking. When the system tells me to turn in a opposite direction to what I am expecting, it is usually shortly followed by a turn in the original direction I was expecting.

It is a very sensitive system.

[No Fly Zone]

With zero specific knowledge of the system(s) at Toronto, I suspect that @767-300ER has nailed it. 300-series airplanes (767 and especially 777) are extremely long frames. While your nose wheel may be ON the center line and in exactly the right place, I think it is possible that the gate approach curve is simply too short for the remainder of the aircraft to become straight-in and before you reach the absolute STOP line. Maybe?
I've heard other 773 drivers mention this about a few other airports, but not at Toronto.
I have no idea how many position sensors the most current automatic docking systems use, but I'm sure that they measure and consider a lot more than the position of your nose wheel.
Have you considered asking your OPS folks to inquire of the folks who operate those systems as Toronto? Sure, there is a tiny degree of tolerance for variations in 'red light generating' position signals, but the 777 drivers need to know what they are. In the case of a few taxiways, alleys and apron gates that are extremely tight, I think a few airports have provided a second, clearly marked guide curve for for the super-longs. I can see the need when parking the A380 and the 747-8.
Does ANY airport currently use 'automagic' gate approach/parking systems for for the latter two?
This is way out of my league, but I'm curious... One heck of a great question! :D