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veldthui

FMC adding waypoint after takeoff runway

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Have looked at the docs numerous times and still have not figured out how to do this easily.What I want to do is add a waypoint a set distance from the end of the runway I am taking off from so the path on the ND is a nice curve instead of a direct line from the bottom of the runway. Some runways have NAV points I can use but most dont and I dont want to begin calculating Lat/Long for a point each time.Example. Taking off from YSSY RW34L I would like to set a waypoint at 6nm from the runway to begin my turn onto the path to the first waypoint.John Veldthuishttp://www.virtualpilots.org/signatures/vpa475.png

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It's a lot easier if you determine the coordinates; the runway coordinates are available from many sources (including, in this case, the yssy.txt sidstar file from Navigraph cycle 0713) lots of free programs will give you a coordinate for a bearing/distance from a known point. The FMC allows you to define a custom waypoint from a known fix given bearning/distance.Since RW34L is in fact defined as a fix in yssy.txt so you should be able to take advantage of assigning a custom waypoint in the FMC following the manual's instructions - but remember you are departing so use RW16R, which is the departure end of 34L.None of this DPs at YSSY follow the track you're defining. So I guess you're just trying to define a VFR departure, why not fly runway heading then make a turn to an intercept course to the first fix?Finally, the course line that is plotted on the ND sometimes has corners in the path instead of a pretty curve because one or more of the waypoints are "floating" but the flight path works out anyway.

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Thanks, I did try that but it does not appear to work most of the time. I have tried the bearing/distance from the runwayby using the RW16R (or equivilent) but it always says not in database.I am defining a VFR departure to the first waypoint and then go back to IFR. This is for practice flying turns and such manually. Thats is why the distance from end of runway to fly runway heading for a set distance/height and then start initial turn to intercept the first waypoint. A totally autopilot flight is a bit boring. I will have a look for one of the programs say should be able to do it and see what happens.John Veldthuishttp://www.virtualpilots.org/signatures/vpa475.png

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Yeah, I forgot the FMC doesn't look into the sidstar file for fixes when you enter them, only the navdata.Well, you can create your own SID in the sidstar file... it wouldn't be hard since the runway fixes are already there.You can get a tutorial from planepath.com and I wouldn't expect it to take more than a few minutes to figure it out.Add the following to the end of the FIXES section:FIX D34L06 COLOCATED RW16R XXX 6 (XXX - the track you want)Add the following to the SIDS section:SID MYSIDRNW 34L FIX D34L06With the tutorial, you can also add your turn to the desired fix.You could also just add a fix to wpNavFIX.txt navdata file but this requires a lat/lon, which you didn't want to do.Lot's of options.. isn't there a DME of anykind at YSSY? Usually there's a VORTAC or ILS/DME somewhere around a major airport like this one.

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I'd be intersted to know if it is possible without amending the sid database, I mean by directly adding a pseudo waypoint in the FMC. It can be done in real world with something like .cha/250/12/h....ThanksGhiom

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Hi John:Use the ARP (Airport Reference Point), that is, use YSSY as a waypoint itself.For that runway (34L) the error (deviation) will not be very big as the ARP for YSSY is very close to 34L (see the AFCAD).Jose Luis.

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I mean, use YSSY itself to create a NAMEBEARING/DISTANCE waypoint.Jose Luis.

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Good idea, I just tried this by sitting on ry34L and using slew to note the mag heading (335) then on the legs page entered the first fix as YSSY335/6 and it works. Depending on where the airport location is with respect to the starting point on the runway, you might have to adjust the bearing (335) and distance to put the fix on the extended centerline at about 6 nm but it will work. Clever, Jose.

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Don't mention it Dan,I've been using that "trick" for months, I always thought it was evident.And as you say, sometimes you have to make slight corrections.Jose Luis.

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