<![CDATA[FMS NAV Path lost after Direct-To IAF in certain circumstances]]>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

  1. Departed DCT AMANA, VILIS, after which STAR and Approach starts.
    Picture 2

  2. 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)
    Picture 2

  3. NAV mode does not track DCT HAIGH
    Picture 3

]]>https://community.justflight.com/topic/10825/fms-nav-path-lost-after-direct-to-iaf-in-certain-circumstancesRSS for NodeWed, 01 Jul 2026 20:40:03 GMTTue, 30 Jun 2026 10:00:09 GMT60<![CDATA[Reply to FMS NAV Path lost after Direct-To IAF in certain circumstances on Wed, 01 Jul 2026 07:25:10 GMT]]>Further observation: it seems the aircraft is losing track seconds after you go DCT OKAKI again.. tried it a few times and can't keep track to OKAKI. Crosswind is about 100kt from the left if that's something to consider too?

]]>https://community.justflight.com/post/51692https://community.justflight.com/post/51692Wed, 01 Jul 2026 07:25:10 GMT<![CDATA[Reply to FMS NAV Path lost after Direct-To IAF in certain circumstances on Wed, 01 Jul 2026 07:15:26 GMT]]>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:

ยด
Screenshot 2026-07-01 091409.png

]]>https://community.justflight.com/post/51691https://community.justflight.com/post/51691Wed, 01 Jul 2026 07:15:26 GMT<![CDATA[Reply to FMS NAV Path lost after Direct-To IAF in certain circumstances on Wed, 01 Jul 2026 00:13:09 GMT]]>It happened to me as well

]]>https://community.justflight.com/post/51679https://community.justflight.com/post/51679Wed, 01 Jul 2026 00:13:09 GMT<![CDATA[Reply to FMS NAV Path lost after Direct-To IAF in certain circumstances on Tue, 30 Jun 2026 20:32:17 GMT]]>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...

]]>https://community.justflight.com/post/51674https://community.justflight.com/post/51674Tue, 30 Jun 2026 20:32:17 GMT<![CDATA[Reply to FMS NAV Path lost after Direct-To IAF in certain circumstances on Tue, 30 Jun 2026 20:07:11 GMT]]>I've noticed this also happens on airports without a sid/star.

]]>https://community.justflight.com/post/51671https://community.justflight.com/post/51671Tue, 30 Jun 2026 20:07:11 GMT<![CDATA[Reply to FMS NAV Path lost after Direct-To IAF in certain circumstances on Tue, 30 Jun 2026 12:06:38 GMT]]>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

]]>https://community.justflight.com/post/51626https://community.justflight.com/post/51626Tue, 30 Jun 2026 12:06:38 GMT