Help with RNAV and G1000

[OSM 683]

10 minutes ago, JRBarrett said:

One thing to be aware of. If you have access to r/w charts, do not try to load any approach marked RNAV(RNP).

I use LittleNav Map and this Chart from SkyVektor.

[JRBarrett 3,121]

1 hour ago, OSM said:

I use LittleNav Map and this Chart from SkyVektor.

That approach is compatible with MSFS - though it does not have LPV vertical guidance.

The approaches to avoid in MSFS are the ones which are marked “RNAV(RNP)” instead of RNAV(GPS).

[snglecoil 1,828]

FWIW there is probably no LPV available for that RNAV 26 approach because of the 200’ towers just off the approach end of the runway in the approach path. That seems to be holding the MDA to 500’ AGL vs. an LPV DA that typically will go as low as 200’ AGL. 

[LarryD 132]

13 hours ago, fppilot said:

Because I was trained and experienced in non-coupled ILS approaches. No AP.  Needles.  Only needles!  Instrument scanning technique. Imprinted process flow.  Still works today.  Integrated GPS is like having a microwave, Instant Pot, or air fryer.... What is your backup?

Seriously this time, I get that.  But, and this is a sincere question here......wouldn't allowing the GPS to fly it actually keep the aircraft centerlined better than by hand anyway?  The computer is making "fine tweaks" constantly, where hand flying requires the eyeball to watch a needle and then respond accordingly.  You are still watching the needle as you say to ensure everything is flowing properly.  Should something start going amiss, the "backup" in this case IS the shift to hand flying.

I am NOT a pilot, I just play one in my basement, but I would like to now know if hand flying the final 5 miles to the runway is the norm, or if it is simply a preference from the pilots that learned the uncoupled technique in the days before modern avionics and just feel more comfortable doing it that way.

[fppilot 4,391]

35 minutes ago, LarryD said:

I am NOT a pilot, I just play one in my basement, but I would like to now know if hand flying the final 5 miles to the runway is the norm, or if it is simply a preference from the pilots that learned the uncoupled technique in the days before modern avionics and just feel more comfortable doing it that way.

I have not actively flown since 1985.  Flew from mid 1971 until then.  I never flew a coupled approach.  Was not in the equipment.  If interested, watch some current youtube videos from "baron pilot", "310 pilot", "martin pauly", "premier 1 driver", and "stevo1 kinevo".  All of them post prolific videos assembled from multiple Go Pro's.  They run the gambit of aircraft types.  Stevo has posted videos from a number of aircraft he flies, and also posts videos of his ride alongs with other pilots. That should give you a good unbiased handle on it.

Jump ahead to about 21:30 in this video and watch a coupled approach down to minimums.
https://www.youtube.com/watch?v=5-gdpR3_HZA

Or this one from about the 25:00 mark. Fully hand flown:
https://www.youtube.com/watch?v=duPRnw-uVRA

Edited October 17, 2020 by fppilot

[OSM 683]

So here is KCLM RNAV 23 amatory Test video. I assume that any Airplane with any Garmin module will show the same result.

Some important findings:

- if your flight plan has the same airport for Departure and Arrival, GPS is not able to calculate RNAV Approach at all. In my case, I made 3 attempts to fly KCLM-KCLM with RNAV Approach without any success. Then I have changed Departure airport to S31 and GPS was able to made correct RNAV calculation.

- AP in APR mode provided only Lateral navigation to the Final Approach Course, in my case to the SEBTY fix, and from SEBTY was Lateral and Vertical Navigation. I used AP to descent to SEBTY fix, from SEBTY AP in APR mode brought  me to the RW23 threshold.

- Carenado M20R HSI has bug - at RNAV mode Dual Glide slope pointer are not showing up.

 

Edited October 17, 2020 by OSM

[Virtual-Chris 682]

On 10/17/2020 at 2:41 AM, OSM said:

Hi Chris!

I will test KCLM RNAV 26 Aapproach with the Live Weather and make a video.

Conditions: M20R with GNS530 1.0.5 mod, start from cold&dark, make a flight plan, Takeoff, add RNAV Approach to flight plan in flight and Land using AP APR mode.

I tried again to do an RNAV approach at Port Hardy (my 2nd plate in the OP) and it worked. I hit the APR approach mode button after reaching the FAF (SIBKA on the chart) and it started following the glide slope down, just as on ILS. I don’t know what I missed the first times. Anyway thanks for the encouragement to keep trying. I’m glad it works.

ps. The glide slope bug is pinned to the top the whole time which is what I think you experienced also. 

Edited October 19, 2020 by Virtual-Chris

[Virtual-Chris 682]

On 10/17/2020 at 10:04 AM, OSM said:

So here is KCLM RNAV 23 amatory Test video. I assume that any Airplane with any Garmin module will show the same result.

Some important findings:

- if your flight plan has the same airport for Departure and Arrival, GPS is not able to calculate RNAV Approach at all. In my case, I made 3 attempts to fly KCLM-KCLM with RNAV Approach without any success. Then I have changed Departure airport to S31 and GPS was able to made correct RNAV calculation.

- AP in APR mode provided only Lateral navigation to the Final Approach Course, in my case to the SEBTY fix, and from SEBTY was Lateral and Vertical Navigation. I used AP to descent to SEBTY fix, from SEBTY AP in APR mode brought  me to the RW23 threshold.

- Carenado M20R HSI has bug - at RNAV mode Dual Glide slope pointer are not showing up.

 

Awesome. I don’t know what I was doing wrong. Must have hit the APR mode too soon (before SEBTY) and then gave up on it. I don’t remember. But it’s good to see this is working. Thanks for investing in this. 

[Virtual-Chris 682]

On 10/16/2020 at 7:09 PM, JRBarrett said:

In a nutshell: All LPV approaches require WAAS, but not all WAAS-enabled approaches offer LPV guidance. The reasons why there may be no “V” available for a given approach vary. It often has something to do with the height or slope of the underlying terrain.  

Even without the vertical component, the LP approach will provide more accurate lateral guidance than a standard RNAV(GPS) non-WAAS approach. 

LPV approaches in MSFS with the G-1000/3000 do seem to “work”, (usually), but there are issues - most notably the fact that the magenta glide path indicator does not respond correctly. Despite that, the aircraft does appear to capture and descend on the LPV glide path, but you have to simply trust that the autopilot “knows what its doing”, because the glide path indicator won’t show the proper indication. 

Thanks. I did get it to work. Appreciate all your input on this thread. I’m very happy to have figured this out. And found something is not really broken for a change (although we shall overlook the glide path indicator being bugged) 😉

[RandallR 449]

On 10/17/2020 at 11:29 AM, LarryD said:

...wouldn't allowing the GPS to fly it actually keep the aircraft centerlined better than by hand anyway?  The computer is making "fine tweaks" constantly, where hand flying requires the eyeball to watch a needle and then respond accordingly.

This is correct.  When I'm especially busy, I let the AP fly the approach.  Just like a VOR or NDB approach, I follow the step-down on the approach plate for vertical guidance, descending by setting the appropriate rate and entering the next min. altitude.