FMS NAV Path lost after Direct-To IAF in certain circumstances
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Tracking direct to the IAF of any ILS approach before entering the STAR segment, the FMS fails to write a new lateral path to the IAF and commands an undefined course on NAV mode. It might happen if you're already in the STAR, but I haven't tried that out due to time restrictions. This has happened on two flights already, one EVRA-EFHK and the other YGEL-YPPH.
For reproducing:
- Fly YGEL-YPPH route with Simbrief recommended profile and set JULIM8A arrival, ILS21.
(On the Z41 Airway, it's common for ATC to give a Direct-To the IAF if traffic permits)
-> En route before entering STAR, set DIR command to HAIGH (IAF RWY 21).
-> FMS should fail to write a path, NAV will track to somewhere completely else
You can also try any other route; it will work the same.
Some pictures from testing YPPH/YPPH
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Departed DCT AMANA, VILIS, after which STAR and Approach starts.
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Selecting DCT IAF (HAIGH) will not display a proper path (note that even though the DCT turn is tight, it wouldn't display a path even if I insert DCT with a better angle)
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NAV mode does not track DCT HAIGH
- Fly YGEL-YPPH route with Simbrief recommended profile and set JULIM8A arrival, ILS21.
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M Merikeri deleted this topic
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M Merikeri restored this topic
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Thank you for reporting this. We would typically request that any feedback such as this be logged via a ticket with Just Flight Support as that's the best way for us to log and keep track of this type of feedback; however, I have been able to replicate this, and I do believe I have identified the root cause.
I have logged this on our internal tracker for our development team to look into further.
Mark - Just Flight
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I've noticed this also happens on airports without a sid/star.
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I have also experienced that!
Only managed to complete my flight after inserting a direct to any X waypoint outside the IAC.
Also noticed that, once you've lost your path you cant insert new Approaches... -
Just happened to me aswell on my flight from EPBY-ENML (EPBY GOBN2B GOBNI Z95 GRUDA N133 PENOR DCT OKAKI DCT EVTOG DCT PIGED DCT VEPUL VEPU4L ENML). Departed EPBY and got a DCT by ATC to PENOR. I don't know the exact trigger where the aircraft went off track, but a few minutes after PENOR, I realised that the plane wasn't on track to OKAKI but going slightly off to the left:
´
