Rnav approach help

[Bigbluss 304]

Hello all,

I was hoping somebody could help me. I've been flying the JustFlight Arrow for many hours now to complete all of the PilotEdge ratings. I've done a lot of research and understood many of these things myself, but I have one area of uncertainty.

Using the GNS530 mod, what is the procedure to fly an rnav approach? The aircraft has no altitude/vnav autopilot so typically my approaches until now have been:

 

1: fly GPS to final waypoint prior to arrival airport

2: ATC provide vectors to intercept the localiser

3: handfly the ILS approach once the GS comes alive.

 

This works because using the ILS I get glideslope indications and it's pretty simply to roughly workout my GS descent rate.

 

How is this performed for an rnav approach with this aircraft? As far as I can see, no vertical guidance is given on my instruments. Is it simply a matter of looking at the chart and being at the correct altitudes for each waypoint? 

 

Many thanks in advance

 

 

 

 

 

 

 

 

[Glenn Fitzpatrick 3,798]

The changelog for April says "- CDI now works with RNAV approaches " .

https://support.justflight.com/support/solutions/articles/17000115071-pa-28r-arrow-iii-msfs-changelog

Cannot help you on how to go about it though .

[Bobsk8 12,492]

The RNAV  in MSFS doesn't have vertical capability. So you use RNAV  for lateral guidance only, and the CDI will show you the lateral path. You can use autopilot to track the approach. . I use EFB for the vertical profile, but if you don't have that, you need to look at the chart for the approach and make sure you are at the right altitude as you fly the approach. Here is an approach I just flew. The bottom right  of the chart shows you  the vertical profile. https://skyvector.com/files/tpp/2104/pdf/09155R20.PDF

 

That is what EFB shows me in real time as I fly the approach, on it's moving map. 

Edited April 29, 2021 by Bobsk8

[Bert Pieke 7,584]

Actually, it does, but it is broken... better fly ILS until it is fixed.

[Dave_YVR 968]

Remember when there used to have a graph on non precision approach plates showing various speeds and the suggested descent rate needed to meet the profile? Good time to reacquaint with the E6b, lol granted there are apps that do all that now. 😉

[hangar 658]

41 minutes ago, Bert Pieke said:

Actually, it does, but it is broken

When did it break, just recently? I was using the g/s on WAAS RNAV's just fine the last time I flew, was probably about 10 days ago.

Is the entire feature no longer functioning again...or is it just that g/s may be inaccurate for certain airports (because ive seen some g/s's way off and some are good?

Also users should be aware that only WAAS enabled Rnav's approaches will offer g/s support, so check the charts for the "WAAS" in upper left corner of chart.

Edited April 29, 2021 by hangar

[vgbaron 3,486]

Same here. I flew a few RNAV approaches in the last two weeks and they worked just fine. Haven't tried any recently however.

[Bobsk8 12,492]

1 hour ago, Bert Pieke said:

Actually, it does, but it is broken... better fly ILS until it is fixed.

Well if it is broken it doesn't work. 

[Bert Pieke 7,584]

28 minutes ago, Bobsk8 said:

Well if it is broken it doesn't work. 

Agreed. 🙂

[Bert Pieke 7,584]

2 hours ago, hangar said:

When did it break, just recently? I was using the g/s on WAAS RNAV's just fine the last time I flew, was probably about 10 days ago.

This may depend on the airplane.. but for the G1000 and GNS530, the vertical guidance has been broken since the start.

The moment you activate the approach, the glideslope indicator appears, most likely pegged at the bottom.

On the real unit, the glideslope indicator does not appear until you are on final, and the FAF is the next fix.  If you are flying at the correct altitude, the GS indicator should be at the top.  Also, the GPS should indicate LPV, or LNAV+V at that moment.

[Bert Pieke 7,584]

2 hours ago, vgbaron said:

Same here. I flew a few RNAV approaches in the last two weeks and they worked just fine. Haven't tried any recently however.

Which airplane?

[blista89 14]

Hi! I'm trying to learn RNAV approaches myself with the JustFlight Arrow, so thought I'd do a quick test and report back. I'm using the GNS530 without any mods.

I did a test flight from Lee on Solent (EGHF) departing runway 23 to Southampton (EGHI) landing runway 02. Southampton has RNAV on runway 02 and the chart is here.

I've taken a few screen shots and comments here.

Key points:

• The IF (BANTU) should be passed above 2,500ft according to the chart, but MSFS seems to be using the FAF (HI02F) height of 1,700ft for the entire first part of the approach.
• Past the FAF the glideslope is correctly captured and you can follow the CDI down to the runway.

Hope the above helps!

[Bert Pieke 7,584]

50 minutes ago, blista89 said:

Hi! I'm trying to learn RNAV approaches myself with the JustFlight Arrow, so thought I'd do a quick test and report back. I'm using the GNS530 without any mods.

.....

Key points:

• The IF (BANTU) should be passed above 2,500ft according to the chart, but MSFS seems to be using the FAF (HI02F) height of 1,700ft for the entire first part of the approach.
• Past the FAF the glideslope is correctly captured and you can follow the CDI down to the runway.

Hope the above helps!

This is indeed the consistent, and incorrect pattern in msfs.

Edited April 29, 2021 by Bert Pieke

[hangar 658]

4 hours ago, Bert Pieke said:

This may depend on the airplane.. but for the G1000 and GNS530, the vertical guidance has been broken since the start.

I think it may depend upon the specific approach/runway as well as I've seen what you describe where it gets pegged at the bottom... but I use the waas approaches nearly all the time and most of the time it works for me (never checked the intercept altitude though so I can't comment on that aspect).

Although from what I can remember I don't think the LNAV+V or LPV indications ever worked for me, but I could be wrong. I think it indicated something like "APPR"...but I'm old and a bit daft sometimes so take it with a grain of salt 🙂

[hangar 658]

1 hour ago, blista89 said:

Past the FAF the glideslope is correctly captured and you can follow the CDI down to the runway.

this sounds like what I've also experienced...it works, but it's really not alive until a little late in the approach, much of the time.

Edited April 29, 2021 by hangar