Noticed in both the TBM and Beechcraft twin (so far as I have not looked into other A/C), when using RNAV, the Garmin will capture the slope, but “count up” from the bottom. When doing an ILS it starts at the top and moves down. Also Magenta (RNAV) vs Green (ILS) which I’m assuming is correct.
Is this the case IRL or should I add a ticket?
Thanks in advance
IRL both should indicate where the GS is in relation to the aircraft. If it is “counting down” that means the aircraft is currently below the extended GS and is flying into it from below. If it is “counting up” that would mean the aircraft is intercepting from above the GS and descending down into the GS. They should both behave the same way. The colors are accurate.
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I can actually concur with the OP; I notice the G1000 on an RNAV approach “reverse-senses” the vertical path. So it shows you too low when you’re too high, or too high when you’re actually too low.
Almost like someone accidentally put a negative sign in the wrong spot when coding the Vertical Deviation scale.
Still need to test some more to be sure that that’s what’s actually happening.
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I have not flown an RNAV approach with vertical guidance yet, but what you describe sounds like a bug to me.
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RNAV approaches are borked and I concur with this. They don’t accurately reflect the glidescope as they would IRL.
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RNAV glide paths are knackered. Like most things in the sim at the moment.
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Thanks, all. It’s what I kind of figured. The approach alts were identical on both planes, at 3000 feet.
I’ll still put in a ticket to reinforce the issue.
+1, definitely put it in the Zendesk. I suspect they’ll fix it in the G1000/3000 overhaul that’s coming months from now, but the more reports the more visibility it has.
Noticing the same with the glide indicator. It comes in from the bottom which is messed up
Most RNAV glide slopes are far too shallow angles that land you down before the runway or
take you through trees or buildings on the approach.
On 1 local airport if I follow the RNAV down it lands me about 1 mile past the end of the runway into Lake Ontario.
I have run a couple of RNAV approaches. Some were accurate, Some were completely wrong.
The behaviour is consistent with LPV approaches (Horizontal and Vertical GPS guidance relative to a path in the computer’s database). Which means the RNAV approaches do not take into account where the runway is, nor what the glide slope angle is : it only gives your directions from one waypoint in the database to an other.
And the LNAV HSI sensitivity is stuck with En-route mode, which makes hand flying RNAV approaches very imprecise.
Also, I have not found any evidence of LNAV/VNAV Baro logic. (Changing the altimeter setting does not affect the glide slope indicator)
The reasons for the problems on many RNAV approaches are not in the RNAV feature itself, but in the waypoints database which is severely deficient.
When the database has wrong data, the RNAV approach will precisely and reliably guide you to the wrong point.
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Ah the infamous GIGO (garbage in garbage out)