AI behaviour when taxiing via runway.

[Guest Loek]

Hi all,In a case like the default Gander (CYQX) AFCAD, traffic coming from the main ramp on their way to runway 22, will stop and stay at the hold short node before runway 13-31. I have seen this before at other airfields where AI is unable to taxi via one runway to the runway in use. I do hope I've made myself clear :( .How can I solve this? By adding the "diamond" crossing? Oh yes, it is FS-9 and I am experienced with AFCAD. Thanks!Loek

[N60JBravo 27]

I think this might have to do with "Hold Short Limits".This is discussed in the Afcad help file. Basically the hold short node is too far from the runway in use.If you press the "H" key in Afcad you can see these limits.Maybe try adding a hold short node on runway 13-31 close to the runway 22 start point.Don't know if it will work, no harm in trying.regards,Joe

[John Hinson 22]

If you put a hold short node on the runway that leads to the active runway, this will usually solve the problem.Alternatively, run an apron path out between the taxiway and the active runway, along the other runway. Stick a hold short node on that.John

[Guest Loek]

Hi John and Joe, Thanks for the swift replies. I had to mention beforehand that I've already tried the option of the hold short node on the runway. To be exact (still about CYQX, Gander) on runway 13, just before entering 22. Result however is that with runway 31 in use, after landing GA will turn around and stop in the middle of the runway before even reaching the runway crossing. So the hold short node on the runway does not seem to be a good idea, but I'll go ahead anyway and try the apron route as John mentions. I do wonder if there is a solution to this. Anybody else? Loek

[John Hinson 22]

Hi John and Joe, Thanks for the swift replies. I had to mention beforehand that I've already tried the option of the hold short node on the runway. To be exact (still about CYQX, Gander) on runway 13, just before entering 22. Result however is that with runway 31 in use, after landing GA will turn around and stop in the middle of the runway before even reaching the runway crossing.

Pardon me but you have moved the goalposts. You have not said whether the solutions I offered solve the problem you described. Instead, you are now saying it doesn't solve a different problem you never mentioned in the first place.I can't think of any situation where arriving traffic does not leaving the runway. It should make its way to an exit (turning back if need be), and if the hold short node is missing it will just sit there. If all parking spots are taken it will vanish. On the original AFD file there is only one exit from Runways 13/31 giving access to/from the ramp other than via other runways. There is definitely scope for improvement to make traffic flow better.I am using an add-on scenery with more comprehensive arrangements - there is access from the ramp to the west end loop, Runway 9/27 is made a taxiway and a further taxiway across a triangle of asphalt in the southeast corner of the junction of Runway 13/31 and 4/22 (not in the FS airport) gives access to Runway 31 and negates the need for the runway hold-short being discussed. The airport seems to work well like this, although it might not be perfectly true to prototype.John

[jvile 1]

snip------I can't think of any situation where arriving traffic does not leaving the runway. It should make its way to an exit (turning back if need be), and if the hold short node is missing it will just sit there. If all parking spots are taken it will vanish. John

AI Planes will vanish from a runway texture if all the taxiway link lines are broke, the runway link line does not match the runway texture number, the depart time becomes earlier than arrival time after the plane has entered the AI Visual Zone Sector and when all parking spots are occupied or parking spots are a smaller meter radius then the planes model radius (FSX uses half wing span value in feet).If a hold short node is missing on the taxiway at the runway vacating point the user/AI plane cannot just sit there. The plane exiting a runway uses a different set of rules then when a plane advances onto the active runway. A missing hold short node for the exiting plane will cause the plane to continue to a parking spot if one exist of proper size. When a hold short is missing the plane will taxi into a parking spot that may already be occupied (double overlayed parking).

[Guest Loek]

Pardon me but you have moved the goalposts. You have not said whether the solutions I offered solve the problem you described. Instead, you are now saying it doesn't solve a different problem you never mentioned in the first place.Hi John,Not really moving goalpost but I should have made clear that I was looking for a solution to work for all circumstances. Sorry for the misunderstanding.In the attachment you will find the screenshot for the CYQX AFCAD I reworked for that particular part of the field. I've also tried it with just the hold short node on runway 31-13 itself just before entering runway 22. This will work for runway 22 only! With 31 in use, traffic will taxi to that hold short node to get their take-off clearance. Fun! Slower traffic landing on 31 will follow the green apron taxi link heading 310 till the turn-off but turns around back to the runway crossing to stop and remain there. So I did find a Gander scenery (by Ed & Mary DesRoches) and installed that one to avoid the problem.So this leads me to conclude there is no solution to this particular situation which will work for all weather and wind situations. It's just another lesson.And I discovered another library coming with this last scenery: "Scenerygenx". I had not heard of this one before. I know runway 12 and NOVA. So I have some reading to do!Cheers,Loek

[John Hinson 22]

So this leads me to conclude there is no solution to this particular situation which will work for all weather and wind situations. It's just another lesson.

Hi Loek,I'm not sure how to access your attachment?I think there is always a solution if you persevere. I'm surprised traffic for Runway 31 doesn't stop at the proper hold-short node but there is a way to get round this too. If you remove the blue node joining the two runways and provide a taxiway link along the runway, joining only with Runway 4/22 and with its own hold short link, traffic for Runway 31 cannot use it.I appreciate you have installed a scenery that should get round the problems completely, but I just felt this should be said because you imply the situation is insoluble.Best wishes,John

[WhiteKnight77 0]

I believe I know what problem you were having as I ran into something similar yesterday and found this after a search as it was closest to my problem. Based on what johnhinson suggested, I tried something similar by adding a taxiway at the turnaround at the end of the runway for 15/33 at CYZF Yellowknife. Ground was telling aircraft to taxi via B A Rwy 27 Rwy 15 to take off via Rwy 33. My AI were stopping at the hold short node for 9/27. Adding the taxiway and hold short node at the turnaround solved the problem of traffic stopping and not taxiing for take off. If there is no turnaround, adding one could help.