Backtracking a runway

[Guest Stamatis]

Hi,In the real world (as well as FS-world) there exist several airports where an aircraft is required to backtrack the main runway in order to reach the threshold and then turn around 180 degrees in order to line-up for takeoff.When such a maneuver is executed by AI Traffic aircraft, they usually end up taking off parallel to the runway and not aligned with its centerline. Reason being that they execute the 180-degree turn starting from the center (middle) of the runway, and not by first turning towards one of the runway sides before exeecuting the turn.Is there a way using AFCAD to better design this 180-degree turn so that the aircraft is properly aligned before commencing its takeoff run?Stamatis

[Guest lmoelleb]

yes! :)

[Guest]

I didn't try it, but what about creating a taxiway link on the edge of the runway ? It would taxi somewhat on the grass I guess but better than nothing.I think the bug about being not-aligned doesn't come from starting the turn on the center-line, but more because they stop turning as soon as they're back on the runway heading, instead of continuing to turn to get re-aligned on the runway center-line. I don't know how Microsoft has programmed it, but you can see aircrafts moving left or right on the taxiways when they're not aligned with the taxiway center-line. So I guess re-alignment can be done, but was "forgotten" for runways. Just a wild guess...__________________________________________________________EricUPDATED: List of all airlines, aircraft manufacturers and aircraft types recognised by ATC:http://www.geocities.com/eric_2203/orhttp://ftp.avsim.com/library/esearch.php?D...atID=fs2002misc

[Guest Stamatis]

Thank you both for your replies.Imoelleb's suggestion looks pretty good though. I will try it and see if it solves the problem.One question though... Is the last taxiwaypoint in the attached gif a hold short node or a normal taxiway node?Stamatis

[Guest]

holdshort nodes have to be off the runway. if they aren't that's where the aircraft will hold short (maybe causing other problems if it's holding short on the runway :D) so my guess is that there are no hold short points in the image he is displaying.-j

[Guest Stamatis]

Yes, but an aircraft gets its clearance to takeoff while waiting at the "hold short" node. If there are none in that picture, how will the ATC figure out that an aircraft is ready for its takeoff clearance?Stamatis

[Guest]

He's only showing the end of the runway. Take a look at MMCS below. The aircraft gets cleared to takeoff at the hold short position before he enters the runway. Then, he travels down the runway, turns around, then takes off.John Taylor

[Guest Stamatis]

Thank you John, that explains it!Stamatis

[Guest]

See the thread below "Intersection Takeoffs", which explains how to create a second runway immediately next to the existing runway. The little AI fellows can then be made to take off from what appears to be the intersection but is a shorter runway in AFCAD.Not easy to do, but it works.

[Shaka 2]

How about the start location? Where does it have to be in relation to the taxi points?- Martin

[Guest lmoelleb]

On the moon or something. :)Startpoints have nothing to do with AI whatsoever. It determines where YOUR plane startes if you start from a runway - AI never starts from the runway! So put it where you would like to start if you select the runway.

[Guest]

>yes! :) I've tried duplicating your success at a little GA airport (3HO) but have had zero success at that.I've had to simply create a dummy taxiway across the grass to get the a/c to line up properly...

[Guest]

>Yes, but an aircraft gets its clearance to takeoff while >waiting at the "hold short" node. If there are none in that >picture, how will the ATC figure out that an aircraft is >ready for its takeoff clearance? >>Stamatis In the case of a runway inwich an aircraft must taxi on to get to the take off position. The hold short point would be where he has not even begun to taxi down the runway. There is an alaskan airport that is the same way. The taxiway connects to the middle of the runway. That connecting taxiway has a hold short. Upon takeoff clearance you have to roll down to the active runway on the runway. Turn around and take off.Pete

[Guest mcleadbeater]

I got round this problem by creating a taxiway parallel- and in very close proximity- to the runway cenreline. What happens is that the A/C taxis up the taxiway line, but looks like it is taxiing very close to the R/W cenreline. It then turns around using a loop similar to the one portrayed above, and then takes off down the centreline. For a demonstration, see my EGNM (Leeds Bradford) AFCAD file.Hope this helpsM

[martoni 0]

This works fine to me too! At the right end a get someconcrete to turn, and in the left they just turns Ok atend of rwy!Regards,