I have come across this before way back in November with the TBM attempting to fly an ILS approach into Orly. Today, flying the AMB9E arrival into the ILS RWY 02 approach via ODILO the AP totally screwed up.
I was approaching the C102 fix to turn onto runway heading, the NAV switched over from GPS to LOC1 however the plane started to fly 180 degrees to this heading. There was nothing I could do to rectify this. I tried telling the AP to fly direct to C102 but there was no effect on the controls.
I have come across this phenomenon at other airports but this is the first time I have had the data to be specific in my report having previously experienced it at the same airport.
Can you post a START screenshot? I couldn’t find any actual one which contains ODILO or or C102.
I haven’t come across this problem, maybe because I used to fly older aircraft IRL which couldn’t intercept the ILS directly from FMS/GPS and required heading mode first and switching the Nav 1 to the ILS.
Maybe this works for you as a workaround (and the way you have to do it on older aircraft)
1.When passing the last waypoint before intercepting the ILS, switch to heading mode and select a ~30° intercept heading.
2. Make sure that Nav1 is tuned to the localizer frequency, the ILS is being displayed and arm the approach mode.
This way is also a good way to establish on the ILS in your above case. Once the AP doesn’t fly direct to the waypoint you want in nav mode, switch to heading mode and navigate to the waypoint manually.
I’m using a Navigraph flight plan with the Navigraph Data overwriting the stock AIRAC so maybe that’s why you can’t see ODILO. The C102 fix is only appearing on my iPad where I was monitoring the flight. In the sectional it equates to the D11.3 OLN fix.
C102 shows up in the Flight Planner (I’m also Navigraph user), so it should appear in the FPL on-board. If you’re using the WTG3000, you’ll definitely see it.
Clarification - are you using Auto-Tuning for the ILS frequency? If so, sometimes it’s not working correctly. For ILS, I double-check the frequency inside Little Nav Map. The waypoint information inside the Garmin may also show it, but I tend to manually type it in and make sure the four-letter alpha Ident shows up next to it to validate.
I’ve been having problems when starting the approach the nav source changes from GPS to localizer. Everything looks normal but the AP turns the aircraft 180° away from the runway. I’d turn off the AP, reprogram the FMS with the approach I was using, and then turn back to the airport. Turning the AP back on turned the aircraft away again. I got out the approach plate to check the info in the FMS. I discovered that the wrong localizer frequency was being used by the FMS. I changed the nav frequency to match the approach plate. The AP then flew the approach correctly. I’m not sure why the wrong frequency was being used.
Once the aircraft turns the wrong way in Nav I don’t waste my time with reprogramming the FMC.
Simply position your aircraft for a new approach and intercept the ILS in heading mode.
Especially if you are flying single pilot without an assisting pilot!
Checking the correct localizer frequency and inbound track are just a few of the vital parts of your approach briefing/check!
That’s your responsibility.
The good news is before FMS switches to LOC1/NAV1, as long as you dialed in the ILS freq manually, it will persist through the change. Verify GS armed switches to Active and you have a rate of descent, enjoy the ride to MDA.
Bonus - if you’re using the Working Title G3000, if ILS decides to quit out at any moment on final, point the green Flight Path Marker on the runway numbers and adjust throttle, instant 3 degree glide slope.
