CRJ not following LNAV route after take-off (ignoring 1st turn)

[steku 22]

My CRJ is often not following LNAV route just after the take-off (ingoring the 1st turn). I have to temporarily switch to HDG, execute the turn into the direction of the 2nd LNAV leg, switch to NAV and then it engages.

SPEED mode is engaged, climbing as expected, AP engaged as well. I would appreciate any hints.

[KuntaKinte 210]

This may be related to some of my bug reports concerning the FMS. Could you please share some screenshots or a video of this situation with a focus on the MFD and the FMS CDU?

[jay jay 93]

I've had similar issues.  It's typically just after takeoff when the first waypoint in the FMS is "vectors".    I'll use HDG to make the first turn which usually is pretty well aligned with the next waypoint and then select the next waypoint via Direct To and then engage NAV.   NAV engages and the selected waypoint shows as active but the aircraft keeps flying on it's original heading.   Only solution I can find is to fly that leg in HDG and then go to NAV for the next leg.    On occasion, the same thing happens on this next leg but that's a rarity.  

[Crabby 28]

VECTORS is NOT a waypoint.  It is a an advisory that the SID or STAR you are flying has a portion where you are expecting RADAR vectors to the first fix.  If you are under ATC control you will fly whatever heading they give you.  If no heading is given on takeoff, you fly runway heading until VECTORED to a different heading.  If you see VECTORS the FMS is waiting for you to hit the Direct To button after ATC assigns you to "Cleared direct XXX".   If you don't have ATC, just choose direct to when ever you want.

[mryan75 3]

Had this happen yesterday. The one thing that I think may have been an issue is that I preselected NAV mode on the ground and hit AP while in the air. It then ignored the first waypoint of the SID and kept climbing straight out. I canned the AP, flew the first few turns by hand, hit AP again, hit NAV again, and it worked fine from there on out. 

[Crabby 28]

3 hours ago, mryan75 said:

Had this happen yesterday. The one thing that I think may have been an issue is that I preselected NAV mode on the ground and hit AP while in the air. It then ignored the first waypoint of the SID and kept climbing straight out. I canned the AP, flew the first few turns by hand, hit AP again, hit NAV again, and it worked fine from there on out. 

What departure?  What was the first waypoint entry in the FMS.  Some departures are flown from takeoff to an intercept point.  If an RNAV departure does not start at the runway, then I fly the departure in HDG mode until I am on an intercept path.  I don't know if this is real world behavior.  Maybe one of our "real world" CRJ pilots can tell us.  What I do know is when flying the AS CRJ in Flight Simulator, this procedure works.  

 

The departures out of KDCA are a good example of what I am talking about where there is an intercept point you should fly to from the runway and then onto the main body of the SID.

[LesOReilly 314]

5 hours ago, mryan75 said:

Had this happen yesterday. The one thing that I think may have been an issue is that I preselected NAV mode on the ground and hit AP while in the air. It then ignored the first waypoint of the SID and kept climbing straight out. I canned the AP, flew the first few turns by hand, hit AP again, hit NAV again, and it worked fine from there on out. 

did you press TOGA ?  that will also "negate" directions and fly straight out... until you engage another mode...  And if the mode you engage is NAV and you see FMS in white then it is armed not active and you will need to use HDG mode to get you on an intercept course for the leg so it can then "activate" and go green.

[bravo77whiskey 0]

I had this problem yesterday. It would not make the first turn. I tried using DIR but it still would not make the turn. 

 

[CRJay 429]

18 minutes ago, bravo77whiskey said:

I had this problem yesterday. It would not make the first turn. I tried using DIR but it still would not make the turn. 

 

You are stuck in TO lateral mode. I see the same thing all the time, for some reason the first engagement of NAV mode does not actually pick up the FMS path despite being right on track.

 

In the real plane, TO mode disappears immediately on selecting NAV mode and is replaced by HDG and then followed by FMS once above 600ft (I believe it is 600ft, would have to check the manuals to be sure). In the AS CRJ I often have to engage NAV mode twice, otherwise it remains stuck in TO mode despite NAV being active on the FCP.

 

Edit: You also managed to capture the ghost waypoint creation when using the DIR INTC function, two bugs in one video  .

[bravo77whiskey 0]

6 minutes ago, CRJay said:

 

You are stuck in TO lateral mode. I see the same thing all the time, for some reason the first engagement of NAV mode does not actually pick up the FMS path despite being right on track.

 

In the real plane, TO mode disappears immediately on selecting NAV mode and is replaced by HDG and then followed by FMS once above 600ft (I believe it is 600ft, would have to check the manuals to be sure). In the AS CRJ I often have to engage NAV mode twice, otherwise it remains stuck in TO mode despite NAV being active on the FCP.

 

Edit: You also managed to capture the ghost waypoint creation when using the DIR INTC function, two bugs in one video  .

Thanks for the explanation. When I pressed NAV I didn't notice that I was still in TO. I'll have to keep an eye out on that from now on. I got the plane a few days ago so there's still a lot to learn.