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Automatically sequence from the end of a STAR to the approach?


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Thinking of getting the TBM but I do have one question.  I know that the default behavior of the LR G1000 is, at the end of the STAR it does not automatically activate the leg from the end of the STAR to the approach...you have to do a Direct To, Activate the Approach or vector yourself manually.  Does the TBM modification of the G1000 address that or do you still have to manually activate that the same way as with the LR version?

Thanks,

Gregg

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A question on top of yours, Gregg: do you know for sure that the real G1000 does it automatically in all cases ?

Also, do you mean "Direct To, Activate the Approach or vector..."     or    "Direct To, or Activate the Approach, or vector..." ?

Just asking because I sometimes experience the sequencing stopping and I haven't been able to figure out why yet :). Looking through the docs and videos hasn't provided an answer yet.

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1 hour ago, xpst said:

A question on top of yours, Gregg: do you know for sure that the real G1000 does it automatically in all cases ?

Also, do you mean "Direct To, Activate the Approach or vector..."     or    "Direct To, or Activate the Approach, or vector..." ?

Just asking because I sometimes experience the sequencing stopping and I haven't been able to figure out why yet :). Looking through the docs and videos hasn't provided an answer yet.

Good questions.  I can't say it always automatically sequences automatically, though, I suspect that it does.  The only real value I have with a G1000 is watching training videos of the real world system on YouTube which makes me far from an expert (though, I have many, many hours with the Flight1 G1000...but who's to say that one's correct?)  The videos I have seen, where there is a discontinuity, the G1000 activates the next leg.  

1 hour ago, xpst said:

Also, do you mean "Direct To, Activate the Approach or vector..."     or    "Direct To, or Activate the Approach, or vector..." ?

The second.  There is a fourth option: "Activate Leg" as well.  

There are a couple of reasons why automatic sequencing is important:

  • If your only altitude restrictions are on the approach and there is a disconnect, you can't use VNAV unless you add a restriction manually on the STAR.  It does not consider anything after the discontinuity.  The workaround for this is to manually add a reasonable altitude restriction at the last fix of the STAR.
  • If you modify your STAR to remove redundant fixes between the STAR and the approach the airplane flies into la la land.  

Here's a situation which illustrates both points at the same time (with another airplane). I was studying the G1000 VNAV by flying various STARs and approaches and decided to try the SUNST4 arrival into McCarran (KLAS) and the ILS 26L.  The SUNST4 links to the ILS26L at PRINO.  Here's the STAR and approach so you can get a sense of what I'm talking about.

https://skyvector.com/files/tpp/1903/pdf/00662SUNST.PDF

https://skyvector.com/files/tpp/1903/pdf/00662IL26L.PDF

I loaded up the STAR and the approach into the flight plan which left PRINO and KLAS at the end of the STAR, followed by PRINO again as the first fix on the approach.  So, I did the obvious thing...delete the PRINO and KLAS at the end of the STAR which, while it cleaned things up and looked right, was a very bad idea.  From looking at the flight plan on the screen it looked perfect but there was that discontinuity in there.  So this is what happened.  First off, at CHIPZ the airplane stopped following VNAV down to the PRINO IAF altitude of 8000.  It was holding at 11,000 feet and I didn't know why...the status indicators were confusing to me.  While I'm trying to sort that out, it got to POKRR and just continued on straight.  Not good.  So I spun the heading dial, did a Direct To PRINO and descended manually.  After I got on the ground and sat thinking about what happened, it occurred to me about the discontinuity.  The G1000 was blind to the approach...it didn't know about the IAF altitude restriction at 8000 and had no connection to PRINO despite it looking that way on the Flight Plan page.  I've pondered various workarounds.  There is simply no way I can think of to get the STAR to link to the approach.  You are going to have to do something manually somewhere in the process.  The best thing I could come up with in this situation was to delete KLAS but LEAVE THAT REDUNDANT FIX (PRINO) IN THERE and, also, add the altitude restriction that's at the ILS IAF to the redundant fix.  Finally, when you pass the last fix prior to the end of the STAR, Activate Approach (but be careful that VNAV doesn't stop when you do!).  More generally, and I mean this seriously, just never trust the G1000 between the end of a STAR and the beginning of the approach...understand the discontinuity and have a plan.  

Gregg

Edited by Gregg Seipp
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Hi Gregg, thanks for that explanation! I gave it a try with the TBM.

Of course you do always need to activate the approach at some point. That's a normal step you generally do not take too early just in case there are last minute changes (ATC, etc). Because of those left turns, I did it just before POKKR, and despite the sharp turn the TBM turned to PRINO and followed the approach.
Then the glideslope became active so normally you don't need vnav mode any more. But I couldn't get the AP to use the GP and flew down by hand too :). That may be because the arrival is plain RNAV and the approach is ILS/LOC so I needed to switch over. I'm not sure, and I need to do a few more tries. I'm still learning, so this may not make sense.

I also need to figure out how to update my X-Plane/TBM nav database. My approaches, arrivals and runways aren't up to date at all (SUNST3, ILS25L) although they're close.

BTW that runway is endless ;) !

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the approach is not connected to the STAR which is paticularly annoying in Europe, where the G1000 considers the transition part of the approach and not the STAR. It makes sense from a procedural point of view but overall it's problematic. For example look at LOWW. Arrive via VENEN (VENEN2W arrival), FL170 at MASUR and after NERDU transition 

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2 hours ago, xpst said:

Of course you do always need to activate the approach at some point.

Actually, it should activate if any of the following occurs:

  • If you activate the approach
  • When you activate a leg which is part of an approach
  • When you enter a leg of the approach but haven't yet activated it.
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On 3/24/2019 at 12:23 AM, Gregg Seipp said:

Actually, it should activate if any of the following occurs: 

  • If you activate the approach
  • When you activate a leg which is part of an approach
  • When you enter a leg of the approach but haven't yet activated it. 

Hi Gregg, I haven't tried the 3rd, so I don't know about that. 

Anyway, if shortly before POKKR you do the 1st or 2nd, then (before you deviate too much from the GS) switch the CDI to NAV1, and select "APR" mode on the Auto Pilot, it flies the plane correctly down the ILS26L approach you have chosen. If you do not switch to NAV1, you will get some guidance, but need to fly down the GS yourself.

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5 minutes ago, xpst said:

Hi Gregg, I haven't tried the 3rd, so I don't know about that. 

Anyway, if shortly before POKKR you do the 1st or 2nd, then (before you deviate too much from the GS) switch the CDI to NAV1, and select "APR" mode on the Auto Pilot, it flies the plane correctly down the ILS26L approach you have chosen. If you do not switch to NAV1, you will get some guidance, but need to fly down the GS yourself.

To be clear on that third point, as you fly along a route the G1000 automatically activates legs when you enter them.  If it activates a leg that is part of the approach then the approach is activated the same as if you had activated it manually.  BTW, here's a good video that shows how the real world G1000 auto-activates the next leg even if there is a discontinuity.  Lots of good information in this video.

 

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