SID Programing

[sagiyanay 1]

Hello guys,Is there any way to program the FMC to fly runway heading up to known altitude, then turn toward the next waypoint? thanks,

[AirbusCG 52]

you could try programming a PBD waypoint in the FMC if you know how much distance you're going to need to climb to that altitude. Otherwise I have no idea...

[sagiyanay 1]

yeah i know, but the climb distance is affected by many elements - wind, speeds etc... it's not fixed distance....

[AirbusCG 52]

that's why I said "if you know the distance". Have you tried looking in the FCOM already?

[wunderlicht 0]

Not to say that I know for sure, but i don't think so.I fly these SIDs without LNAV, using either VOR, heading control, or by hand. Take the PORTE3 departure from KSFO, great practice for exactly what you are asking about. If you let the FMC take the departure in LNAV mode you'll badly abuse the procedure.Might pay to take a look at it and see how the FMC judges the turns. I can't say for sure because I just ignore whatever it says.

[Rieder 3]

What I tend to do, right or wrong is set it to fly VNAV and set a hold on heading, but not LNAV until its clear of the airport. I did this because sometimes their`s a tight turn involved almost as soon as I leave some airports. I then open the CDU and line select the next forward facing waypoint, finally clicking on LNAV. Its only like intersecting the route before selecting and using it. For most airports I can just click on LNAV and VNAV as normal. Sometimes you just have to do what you think is best. for you at the time. Steve

[trisager 2]

Is there any way to program the FMC to fly runway heading up to known altitude, then turn toward the next waypoint?

No, you cannot create conditional waypoints using the CDU.

[Spin737 102]

If you let the FMC take the departure in LNAV mode you'll badly abuse the procedure.

What does it do that that is objectionable?

[wunderlicht 0]

What does it do that that is objectionable?

Well, from what I noticed it continued out too far on both 1L/R and 28L/R initial heading which would overshoot the next assigned heading and not make the third turn in time. Causing overcorrections.To me it's just a smoother departure when done manually.

[Sekstifire 10]

No, you cannot create conditional waypoints using the CDU.

I dont know how to manually program it either, but I'm pretty sure that the procedures from Navigraph contains instructions that says "climb to altitude X, then turn left hdg YYY"

[Spin737 102]

Well, from what I noticed it continued out too far on both 1L/R and 28L/R initial heading which would overshoot the next assigned heading and not make the third turn in time. Causing overcorrections. To me it's just a smoother departure when done manually.

Hmmm. What does the MAP look like before you depart? Does it generally match the depiction on PORTE3? Does the LEGS page match? The LNAV should have no problem following the conditional waypoints. When you say it continued out too far, did the next waypoint sequence when you got to the altitude for the turn (eg. 1,600' for 1L)?

[vonmar 123]

Like this: YMHBSID KAREN4RNW 12 TRK 120 UNTIL 1000 TRK 350 UNTIL 8.0 FROM FIX HB FIX D353O FIX KAREN

[Spin737 102]

Like this: YMHBSID KAREN4RNW 12 TRK 120 UNTIL 1000 TRK 350 UNTIL 8.0 FROM FIX HB FIX D353O FIX KAREN

Note that your legs are TRK and not HDG. Unfortunately, countries differ on whether you should fly the RWY HDG or TRK when you're told to fly runway heading.

[davidz 26]

Runway heading means heading. The chart requires a track of 120. This only occurs with procedural SIDs. When issued with "runway heading" on a radar SID, you should never correct for wind. You would only correct for wind if instructed to "fly runway track".

[trisager 2]

I dont know how to manually program it either, but I'm pretty sure that the procedures from Navigraph contains instructions that says "climb to altitude X, then turn left hdg YYY"

Yes, it works as part of a procedure. You cannot program it using the CDU.