[1.0.7] LNAV not following SID route

[crisk73]

The flightplan is: LIPX LUMA5S LUMAV UZ982 ANC UL612 TRL UJ65 BAVES LGIR

LNAV is engaged but it doesn't even perform the first right turn as per SID, the plane goes straight ahead indefinitely.

Can anybody replicate it please? I tried several times but without success. Using Aerosoft NavdataPro cycle 1607.

Thanks.

Cris

GizmoLog.txt

IXEG_FMS_debug.txt

[mmerelles]

i tried ro recreate your flight and had the same weird behavior. The aircraft does not try to join and follow the magenta to the right when engaging LNAV.

Because you did not select any arrival star neither runway (which was a problem on the past), i tried recreating the flight again but selecting BAVES1 arrival and runway 27. i selected the arrival procedure with no issue, as soon as i selected runway 27 and i had a gizmo soft crash!

 

I cleared everything and managed to complete the fmc programing including the arrival and runway.

 

Departed again and had the same weird LNAV behavior, i manually pressed LSk3 and then LSK1 skipping the initial LSK1 conditional and LSK2 (int) orders from the legs page and now LNAV was able to turn right and join the magenta properly.

A bit later i realized VNAV was unable to engage, i had to remove the miss approach procedure from the legs page leaving RW27 as the last step on the plan for the fmc to allow me engaging vnav and resume the flight.

 

conclusion:

there is a big mess here trying to recreate this flight, full of problems. I wonder whether this is related to navigraph database (running 1607rev2 here) or part of the fmc fine tuning still in progress.

 

the developers should try to recreate this flight and shed some light here.

 

Edited June 28, 2016 by mmerelles
misspelling

[Litjan]

Thanks for the reports and the investigative efforts! We will look at this one!

Jan

 

[crisk73]

Thank you@mmerelles for your try. I don't think it's navdata fault as I have Aerosoft navdata and as I see the issue is the same.

Removing the first two conditional waypoints (750) and (intc) and manually selecting the first non conditional one makes the magenta line be joined but I remember I did this same route with 1.0.5 without problems. Thanks again!

Cris

[StefanH75]

Same here. Route is EHAM BERG2R EH022 DIRECT BERGI L602 SUPUR UL60 OTBED DIRECT MONTY KEGU1D REXAM DIRECT REXAM APPR TRANS ILV75 ILS09 RW09 MISSED APPR LPLNB EGGP. LNAV is leaving route after passing waypoint OTBED.  Is there a solution for this?

 

IXEG_FMS_debug.txt

[crisk73]

I confirm that passing OTBED, LNAV is no more able to head to MONTY neither forcing it with a DIR TO. The only solution is HDG mode.

[tkyler]

I just fixed a bug from another report that I believe is related to this.  Whenever you have an acute turn at a waypoint...and the next waypoint after the acute turn is too close to make (bypass)....then the plane would depart the LNAV path after teh waypoint BEFORE the acute turn.  This bug is due to our "look ahead" code that tries to anticiapte turns in order to give better LNAV tracking

I just enterd the route and see the waypoint combo I expected to see (OTBED > MONTY > WAL24)....and the route draws well now (it was kink'd before).  So I think this is fixed for the next update.

-tkyler

[aljaz41]

Thanks @tkyler. I found another problem regarding LNAV but in this case the waypoints aren't that close together. Departing LJLJ runway 12 and following either BERTA 2D or GIMIX 2D which both require a right turn after MG to intercept QDR 177. However, after passing MG the plane initiates a right turn but it never levels off on a 177 track. Instead it maintains right bank, doing 360s. I assume these two problems are not related but of course I might be wrong.