Garmin 430 "Steep Turn Ahead"

Dave Theisen said:
@SixPapaCharlie, You selected WALON as the IAF, at that point, even though it is charted as an IAF, ILOPY is just the next fix on the approach. When you selected Direct ILOPY, the GPS is going to go direct to that fix, but then go direct LUTNY because that is the next fix on the approach. Because its such a sharp turn, the GPS really doesn’t know how to do it. What is causing the confusion is that the holding turn in lieu of a procedure turn is identical to the holding pattern for the missed approach. So as you had it set up, the “picture” looked like you where set up to do a procedure turn, but the flight plan would have showed to true story. In this particular case, what you would have had to do is re-enter the approach and then selected ILOPY as the IAF.

Make sense?
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If it represented the Missed Approach Hold, it wouldn't be Magenta yet, would it?
 
luvflyin said:
If it represented the Missed Approach Hold, it wouldn't be Magenta yet, would it?
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I’d be curious to see if Bryan sets it up again exactly like he did, if it truly was magenta or not. With everything being co-located like that, it is sometimes tough to decipher what you are really looking at.
 
Dave Theisen said:
@SixPapaCharlie, You selected WALON as the IAF, at that point, even though it is charted as an IAF, ILOPY is just the next fix on the approach. When you selected Direct ILOPY, the GPS is going to go direct to that fix, but then go direct LUTNY because that is the next fix on the approach. Because its such a sharp turn, the GPS really doesn’t know how to do it. What is causing the confusion is that the holding turn in lieu of a procedure turn is identical to the holding pattern for the missed approach. So as you had it set up, the “picture” looked like you where set up to do a procedure turn, but the flight plan would have showed to true story. In this particular case, what you would have had to do is re-enter the approach and then selected ILOPY as the IAF.

Make sense?
Click to expand...
I think you're right. Since the 430 wanted to go to WALON when he activated the approach, that must have been the IAF he chose when he loaded the approach in the first place. Selecting that IAF would have caused the NoPT notation to be in effect, thus the steep turn warning, because navigating direct to ILOPY does not override his selection of WALON as the IAF. (ILOPY is both an IAF and an IF, but choosing WALON as the IAF causes ILOPY to be treated solely as an IF.)

I agree that the way to prevent this would have been to reload the approach when he was given direct ILOPY, and this time select that fix as the IAF.
 
Dave Theisen said:
I’d be curious to see if Bryan sets it up again exactly like he did, if it truly was magenta or not. With everything being co-located like that, it is sometimes tough to decipher what you are really looking at.
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It's too bad that there is apparently no way to get an up-to-date database for Garmin's 430 trainer software. Maybe there's a comparable approach in the old database that could be used to test this.
 
Thinking about this some more, even if it was set up correctly to do a procedure turn after ILOPY as the IAF, that turn wouldn’t be magenta until he got to ILOPY. I really think this is just a case of the brain seeing what it thinks it should see.
 
As others have said, if you load the approach starting at WALON then you will be on a NoPT segement to ILOPY. If you hit the FPL button and scroll down to ILOPY and hit Direct Enter Enter it will take you direct to ILOPY and you will NOT get a procedure turn. The garmin has to make more than a 90 degree turn and will lead the turn by quite a bit to make it work with standard rate turns (hence the steep turn ahead msg). If you want the procedure turn, you must re-load the approach starting at ILOPY then select "yes" to add the course reversal (procedure turn). Box did exactly what you told it to do. I see it all the time with students getting confused if they have a PT or if they should have a PT.

Always, always, always review the FLP page after you load an approach. Make sure it matches your intent. If "hold" is not in there you won't get a procedure turn.
 
I flew it on the Garmin desktop simulator. cycle 1513 10-DEC-2015 07-JAN-2016. No idea how many software updates there have been since then. It was the RNAV RWY 18 Approach then. WALON didn't exist but TEYUS did as an IAF, not a feeder as it is now. I selected and loaded the Approach with IAF TEYUS It was obviously a NoPT fix by the way it loaded. I activated the Approach after passing BLECO. It turned Direct to TEYUS as expected. I went to FPL, got a cursor, went to ILOPY and Direct enter entered it. Present position Direct ILOPY goes magenta and plane goes Direct ILOPY. Got the steep turn ahead thing. When I got closer I slowed way down so it wouldn't get weird. It did a 'flyby' of ILOPY and turned to LUTNY, segment is now Magenta and it sequences right on down to the Runway. At Missed Approach Point I climb and OBS goes to SUSP as expected. I unsuspend. ILOPY is the Missed Approach Fix. But there are two fixes in between unlike now where it is Direct. I let it fly it's Missed Approach, ALBEW BECHY ILOPY. At no time during all of this is the Holding Pattern at ILOPY magenta. It does not turn magenta until crossing ILOPY where it does a Teardrop entry and flys the HOLD
 
luvflyin said:
I flew it on the Garmin desktop simulator. cycle 1513 10-DEC-2015 07-JAN-2016. No idea how many software updates there have been since then. It was the RNAV RWY 18 Approach then. WALON didn't exist but TEYUS did as an IAF, not a feeder as it is now. I selected and loaded the Approach with IAF TEYUS It was obviously a NoPT fix by the way it loaded. I activated the Approach after passing BLECO. It turned Direct to TEYUS as expected. I went to FPL, got a cursor, went to ILOPY and Direct enter entered it. Present position Direct ILOPY goes magenta and plane goes Direct ILOPY. Got the steep turn ahead thing. When I got closer I slowed way down so it wouldn't get weird. It did a 'flyby' of ILOPY and turned to LUTNY, segment is now Magenta and it sequences right on down to the Runway. At Missed Approach Point I climb and OBS goes to SUSP as expected. I unsuspend. ILOPY is the Missed Approach Fix. But there are two fixes in between unlike now where it is Direct. I let it fly it's Missed Approach, ALBEW BECHY ILOPY. At no time during all of this is the Holding Pattern at ILOPY magenta. It does not turn magenta until crossing ILOPY where it does a Teardrop entry and flys the HOLD
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I tried it with a similar approach that I have a old matching chart for, and I noticed that when I selected a NoPT IAF, it didn't depict the HILPT at all. It did depict it (in the colors you described) when I selected the IAF that is at the holding fix.
 
Dave Theisen said:
@SixPapaCharlie, You selected WALON as the IAF, at that point, even though it is charted as an IAF, ILOPY is just the next fix on the approach. When you selected Direct ILOPY, the GPS is going to go direct to that fix, but then go direct LUTNY because that is the next fix on the approach.
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I was starting to write that. Exactly. You can easily set up that scenario with the same result on any Garmin or Avidyne emulator. When you select a NoPT transition, you don't get a PT.

There's a reason I set up things like this when I give recurrent instrument training and IPCs.
 
By the way, at one point I did get the "steep turn ahead" message from the trainer software. In my case, it happened when I accidentally sent myself to a NoPT IAF from a direction that required a hairpin turn to get on the initial segment of the approach.
 
This is the same scenario in a brand new 750xi, except I'm coming from the east rather than the south. The first photo is with WALON as the transition. The second with ILOPY as the transition. One has the hold in lieu. The other doesn't. D923A1D2-4EB4-47E2-9947-CA8C20410016.jpeg
F897484D-03E0-4792-BA26-30532226FF1A.jpeg
 
Hahaha. I just went out and flew that approach again about eight times and I was able to recreate it. Dave is exactly right if I put in the approach and choose Waylon as the initial approach fix then I go direct Ilopy The Garmin doesn't treat that as an initial approach fix and does not insert the hold.

If I reload the approach and do direct Ilopy it puts the procedure turn in there.

I filmed the whole thing doing it multiple different ways with different outcomes but I think we've figured this one out I don't feel like editing a bunch of video but that was definitely the issue
 
This time I put it in the same way I did yesterday and I let the autopilot have its way and it just did a 180 and flew me down to final.

Makes sense but I would think it would be smart enough to say hey he's deviating to a different initial approach fix and treat it as such but now that I know it's fairly easy to do
 
SixPapaCharlie said:
This time I put it in the same way I did yesterday and I let the autopilot have its way and it just did a 180 and flew me down to final.

Makes sense but I would think it would be smart enough to say hey he's deviating to a different initial approach fix and treat it as such but now that I know it's fairly easy to do
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At least it's smart enough to warn you about the steep turn.
 
SixPapaCharlie said:
Makes sense but I would think it would be smart enough to say hey he's deviating to a different initial approach fix and treat it as such but now that I know it's fairly easy to do
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Giving the box too much credit. Loading an approach just loads a set of waypoints (with a little metadata added to tell it what to do with CDI sensitivity and such). Telling to skip some waypoints isn't going to make it think you wanted a different set.

I can't remember who originally made this observation, but the Garmin terminology of "activating" an approach has caused a lot of pilots to be misled from understanding what it's actually doing.
 
SixPapaCharlie said:
This time I put it in the same way I did yesterday and I let the autopilot have its way and it just did a 180 and flew me down to final.

Makes sense but I would think it would be smart enough to say hey he's deviating to a different initial approach fix and treat it as such but now that I know it's fairly easy to do
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It can only to what the PIC tells it to do. It's not AI or even a little smart.

hmmm.... GPS as HAL....? Instead of "steep turn ahead," perhaps a voice, "Sorry, I can't do that, Dave."
 
dmspilot said:
Giving the box too much credit. Loading an approach just loads a set of waypoints (with a little metadata added to tell it what to do with CDI sensitivity and such). Telling to skip some waypoints isn't going to make it think you wanted a different set.

I can't remember who originally made this observation, but the Garmin terminology of "activating" an approach has caused a lot of pilots to be misled from understanding what it's actually doing.
Click to expand...

I agree. It took me a while to understand what "activation" really does. It simply skips all the enroute fixes and jumps to the first fix in the approach group. An approach is just another sequence of waypoints. The interesting thing is, the approach is not tied to the enroute destination. You can load and activate an approach that is thousands of miles from the "destination".
 
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Glad you figured it out! But tell me. When the 430 started flashing “steep turn ahead “ did you reach up and put your hand on the red handle? Be honest, maybe just touch it?
 
SixPapaCharlie said:
Hahaha. I just went out and flew that approach again about eight times and I was able to recreate it. Dave is exactly right if I put in the approach and choose Waylon as the initial approach fix then I go direct Ilopy The Garmin doesn't treat that as an initial approach fix and does not insert the hold.

If I reload the approach and do direct Ilopy it puts the procedure turn in there.

I filmed the whole thing doing it multiple different ways with different outcomes but I think we've figured this one out I don't feel like editing a bunch of video but that was definitely the issue
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All right. You got this baby nailed. If you do this Approach on the check ride you do the know DPE is going to fail the 430 don’t you?
 
luvflyin said:
All right. You got this baby nailed. If you do this Approach on the check ride you do the know DPE is going to fail the 430 don’t you?
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That's why Cirrus gives you 2 of em ;)

Screenshot_7.jpg
 
SixPapaCharlie said:
This time I put it in the same way I did yesterday and I let the autopilot have its way and it just did a 180 and flew me down to final.

Makes sense but I would think it would be smart enough to say hey he's deviating to a different initial approach fix and treat it as such but now that I know it's fairly easy to do
Click to expand...

The workaround to to re-select the approach with the new IAF so you get correct sequencing. The 430 has know way of knowing if you are changing IAFs instead of just skipping to the next waypoint. Whenever a GPS box does something weird, it pays to look at the flight plan page and see what way points it is feeding you.

FYI for some GPS HILPT approaches you won't get asked if you want to fly the course reversal. It just puts it in and expects you to delete it if necessary. The GPS 35 into KVGC works this way. It can't figure out if you are in a NoPT heading or not, so I have to delete the hold while inbound to the IAF. Then the sequencing is correct.
 
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Dave Theisen said:
Thinking about this some more, even if it was set up correctly to do a procedure turn after ILOPY as the IAF, that turn wouldn’t be magenta until he got to ILOPY. I really think this is just a case of the brain seeing what it thinks it should see.
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And the above comment about the user interface showing things that "seem right" on the moving map, when the computer is thinking in terms of waypoint to waypoint is an interesting case study in how hard it is to create a user interface that's visual for stuff.

If the UI put little numbers next to each waypoint it's using, in the order it thinks it's going to fly them, that might be very useful in certain misprogramming scenarios...

1, 2, 3... Wait a minute...

Especially on approaches.

It also shows an interesting mind game issue -- how visually oriented is the pilot to pictures versus lists. If the picture gives you warm fuzzies you might not really read the flight plan list carefully.

Interesting challenge for training too. It was actually hard for my CFIIs to get me to even use the moving map. I didn't trust it after a couple decades of not having one. Ha. I wanted to focus on the six pack. Someone who's done ALL moving map probably trusts them more/too much.

Fun stuff to think about how the human interface via the eyeballs and brain work when just looking at two screens... Flight plan list and the map. Quite a bit to unpack there if you're the map display designer.
 
Should have activated the next leg instead of the approach.
It wanted to do the whole thing over again with the IAF I had originally selected.
 
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