Help with RNAV and G1000

[Virtual-Chris 682]

Hi,

First, I'm wondering if the Caravan (my GA plane of preference these days) offers any vertical decent assistance with RNAV approaches... either LPV or LNAV?  Does anyone know?

Also, how to interpret RNAV approach plates...

This airport in Port Angeles has a WAAS notation at the top which should support an LPV approach with vertical guidance, but I don't see LPV mentioned in the table at the bottom.  Is it only LNAV?  Why offer WAAS if not LPV? What number is the actual minimums here?

Here's another one... Port Hardy...  It seems more basic than the previous.  It has a WAAS channel at the top, and what looks like an LPV minimum at the bottom...  Does this runway support LPV?

Am I reading this right that you should be at 3100ft at SIBKA?  And the minimum altitude before PUXUM is 1700ft?

Edited October 16, 2020 by Virtual-Chris

[AmeliaCat 201]

I am wondering the same thing about rnav in the caravan,,cant get any answers.  I guess once you get to Cobux turn FD and APP on and if it follows the flight path then it does? 

I believe your reading the plates correctly..sorry cant be of more help hopefully someone comes along and answers....

[AmeliaCat 201]

i guess ill try the approach fro CLM and see what happens..

[marsman2020 1,310]

RNAV is hit or miss.  Some approaches are missing the vertical nav info the G1000 needs, or don't work at all.  Some approaches the AP will follow the glidescope properly, but the 'pip' on the glidescope dispaly stays pegged even though the plane is following the right altitude.  Some RNAVs work fine.  (I've had all of these cases happen).

Also, if you just try to fly to a random airport and select the approach on the G1000 (without putting that airport as a destination in the world map before you take off) - that seems to cause the G1000 to not load the RNAV data at all.

The best advice I can offer at this point is to have LittleNavMap 2.6.1 with the MSFS nav database in it running on a 2nd screen and be prepared to fly the approach by hand or by commanding AP VS rates as a non-precision approach if for some reason the vertical guidance doesn't work, or you can't load the waypoints into the G1000. 

 

Edited October 16, 2020 by marsman2020

[AmeliaCat 201]

2 minutes ago, marsman2020 said:

RNAV is hit or miss.  Some approaches are missing the vertical nav info the G1000 needs, or don't work at all.  Some approaches the AP will follow the glidescope properly, but the 'pip' on the glidescope dispaly stays pegged even though the plane is following the right altitude.  Some RNAVs work fine.  (I've had all of these cases happen).

Also, if you just try to fly to a random airport and select the approach on the G1000 (without putting that airport as a destination in the world map before you take off) - that seems to cause the G1000 to not load the RNAV data at all.

The best advice I can offer at this point is to have LittleNavMap 2.6.1 with the MSFS nav database in it running on a 2nd screen and be prepared to fly the approach by hand or by commanding AP VS rates as a non-precision approach if for some reason the vertical guidance doesn't work, or you can't load the waypoints into the G1000. 

 

I am doint that right this moment

[marsman2020 1,310]

Here's a good FAQ from the FAA on what the different US approach chart notations mean - https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/library/factsheets/media/RNAV_QFSheet.pdf

LP has no approved vertical guidance, but some GPSes might display "advisory vertical guidance".  I'm not sure what the MSFS G1000 does in this case.

[Virtual-Chris 682]

14 minutes ago, marsman2020 said:

Here's a good FAQ from the FAA on what the different US approach chart notations mean - https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/library/factsheets/media/RNAV_QFSheet.pdf

LP has no approved vertical guidance, but some GPSes might display "advisory vertical guidance".  I'm not sure what the MSFS G1000 does in this case.

That didn’t help. When looking at the minimums line on the charts above, there are several numbers there... what are all those numbers? E.g. 920-1 638(700-1) then 920-1 3/4 638(700-1 3/4) ... is there a decision altitude in there somewhere? 😉

[marsman2020 1,310]

https://www.faa.gov/air_traffic/flight_info/aeronav/Digital_Products/aero_guide/media/editions/cug-tpp-edition.pdf

[AmeliaCat 201]

I just tried the rnav for Kclm.. flew out to wattr and  chose proc 26rnav wattr and then pressed ap ,apr fd and alt... which took me to the airport but my course was south of the way points I was under the impression i would fly right over them....?  also my altitude did not change by its self ... 

[AmeliaCat 201]

ah i just figured out that i have to choose ifr rnav in main map menu,,, how supid  why cnt i do this in the air ?

[AmeliaCat 201]

34 minutes ago, AmeliaCat said:

Also, if you just try to fly to a random airport and select the approach on the G1000 (without putting that airport as a destination in the world map before you take off) - that seems to cause the G1000 to not load the RNAV data at all.

yes i saw that too

[Virtual-Chris 682]

11 hours ago, marsman2020 said:

https://www.faa.gov/air_traffic/flight_info/aeronav/Digital_Products/aero_guide/media/editions/cug-tpp-edition.pdf

Thanks for that!  So the first number is the Decision Altitude, the 2nd number is visibility in miles and the numbers in parenthesis are for military.

So my next question is... how do you use the visibility number?  For example, for Port Angeles (in the original post) the minimums for LNAV are 920-1 which is 920' and 1 mile.  So if you can't see the runway before 920', you call a missed approach and go around. What do you do with the 1 mile?

[Virtual-Chris 682]

Oh, and I guess we can conclude that LNAV and LPV approaches are not supported with the G1000.  I wonder if they are supported in the A320?

[marsman2020 1,310]

The real G1000 supports them and the one in the game is hit or miss. I flew an LPV approach last weekend, the AP followed the glidepath properly but the indicator 'pip' on the altitude display stayed pegged at the top for some reason. (So I couldn't have flown it manually if I wanted to).

The difference between LPV and LNAV/VNAV or LP and LNAV is down to the equipment on the aircraft.  

[Bert Pieke 7,584]

58 minutes ago, marsman2020 said:

The real G1000 supports them and the one in the game is hit or miss.

The "safe" strategy for now, is to fly ILS approaches.. The ILS glideslope is driven off the NAV1 radio and not the GPS.

I would much prefer to fly RNAV approaches, but at present, they are broken in several ways, and the wrong time to realize that is when you are trying to land the airplane 🙂