RNAV in 172

[anitelite 41]

I've tried a couple of times to do a RNAV approach in the 172.   But I don't think I'm coupling the Garmin correctly after receiving clearance for the approach.  I don't have a manual or reference video to work from, so any assistance or suggestions welcome.  Thanks

[mtr75 653]

Need more information. I don't know the G1000 very well, but you might be loading the approach but not activating it. You also might not be using approach mode? I really can't tell you from what you've written.

What steps do you take and what happens?

[Bert Pieke 7,585]

Not sure what your approach checklist is... but the well established sequence is:

1. Activate the Approach in the GTN , with the GTN in GPS mode, and NAV / ALT modes on the autopilot

2. After turning to final, check that the glideslope indicator is alive and above the airplane

3. Select APR mode on the autopilot

Unfortunately, the RNAV glideslope indicators do not operate correctly in MSFS, so you will likely find yourself above the glidepath.. At that point APR mode will not capture the glidepath.

A temporary workaround is to come in at a lower altitude than the intercept point... Try 1200 feet AGL or so..  Or, just handfly the approach.

Hopefully, Asobo will fix this 😉

 

Alternately, you can select an ILS approach which currently works more reliably. It has more steps:

1. Activate the Approach in the GTN , with the GTN in GPS mode, and NAV / ALT modes on the autopilot

2. Dial in the ILS frequency on the NAV1 radio

3. Set the heading bug to the runway heading

4. After turning to final, select HDG mode on the autopilot, and select VLOC mode on the GTN

5. Check that the glideslope indicator is alive and above the airplane

6. Select APR mode on the autopilot

Edited September 7, 2020 by Bert Pieke

[GearUp180 55]

5 hours ago, anitelite said:

I've tried a couple of times to do a RNAV approach in the 172.   But I don't think I'm coupling the Garmin correctly after receiving clearance for the approach.  I don't have a manual or reference video to work from, so any assistance or suggestions welcome.  Thanks

A Google search with "C172+G1000+manual" provides you with the link to the manual from Garmin:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwj0g4jT89frAhVBz4UKHSCCBB8QFjABegQIBBAB&url=https%3A%2F%2Fstatic.garmincdn.com%2Fpumac%2F190-00384-12_0A_Web.pdf&usg=AOvVaw3R4B8nqICHO2H6vKGHrImZ

Section 9 (Procedures) / Chapter 2 covers the approaches (including GNSS).

[anitelite 41]

Thanks for all the excellent and prompt responses.  mtr75  called this one right off the bat.  I was selecting the approach but not activating it.  Once activated, the autopilot drove the course without issue.  On the final approach fix, however, i deliberately caught it a little low since other writers had suggested that if you started too high, the glideslope wasn't captured.  So the glideslope came alive and I watched the approach to the runway and it was quite accurate.....until the very end.  Had I allowed it to complete, it would have put me about a quarter mile short of the runway....Not a big deal, but I was a little surprised.  Anyway...thanks to all for the excellent help and written reference material. 

[mtndog9 0]

I have also been unsuccessful with RNAV/172 landings. Tried to capture a number of Glide Paths at various airfields at the fix and altitude specified on the approach plate and when I hit APR for the autopilot (G1000) the AP goes nuts. After seeing some clues on Avsim, tried capturing at a lower altitude...still no "GS" capture success until the diamond came above the center, which was 500 AGL (+/-). Note: X-Plane G1000 RNAV on 172 works perfect if one hits APR just when fix is crossed at specified altitude on the  plate...also indicates "GP" on the AP status line, rather than "GS" on MSFS 2000. Seems like a major bug needing a patch, hopefully in the next release.

 

 

 

[jrw4 624]

Since you seem to be referring to the G1000 version of the C172, is there any reason why you aren't using the nXi version that is available free through the MSFS Store? RNAV approaches should work fine, or at least the ones I have tried do so.

Good luck.