KASE approach clarication

Hello - more of a query I think than an issue.

Looking at the charts there are 2 instrument approaches to KASE, however, in sim there appear to be 4. 2 which are specific to RWY 15 and 2 that are not.

The 2 that do not note a runway seem to match up with the charts and the 2 with RWY 15 denoted seem to follow the same path but contain different way points that do not appear on the charts (only in sim?)

The 2 with RWY 15 seem to include the correct missed approach procedures too, whilst the two with ‘00’ do not have any.

Wondered if anyone could clarify why there are the additional 2 or are there some charts missing?

Thanks,
Rob

Aspen actually has at least 5 approaches:

  • LOC DME-E
  • RNAV(GPS)-F
  • LOC/DME 15
  • RNAV (GPS) Z RWY 15
  • RNAV (RNP) Y RWY 15

The first 2 are the only public approaches, and that appears to be what Navigraph charts is showing. Since the other 3 require specific approval, they won’t typically be in the real life nav database and chart subscriptions - unless you are an approved operator (such as NetJets, etc). That’s because they have waivers for obstacle clearance requirements, etc.

There is also a charted visual procedure (Roaring Fork), but it is pretty rare to fly this. The LOC DME-E is the most common. It is incorrectly labeled LOC 00 E in the sim.

Maybe Navigraph can improve the Jepp Chart subscription to include more of these special procedures?

Thanks! Makes more sense now.

Could I ask another question? Is the localiser for this runway located off site? The depiction seems to have it end at CEYAG and this seems congruent with the sim where it will lose the localiser at or around this point. Though looking at other (non-jeppessen) the depiction shows the localiser all the way down to the rwy.

Thanks again,
Rob

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The localizer for the main part of the approach (I-ASE) is located in the normal position (off the opposite end of the runway). But the missed approach procedure involves tracking another localizer / LDA (I-PKN), which is located on top of Aspen Mountain (southeast of the airport).

Since the missed approach point (CEYAG) is moved back 2.6nm from the end of the runway (to allow for terrain clearance on the missed), I suspect that is why it is charted with the localizer depiction stopping there. Just a guess though.

I wonder if someone from the Navigraph team could comment on this?

Hi guys,
this is not planned at the moment - such procedures are normally special procedures for a few airlines, which they pay a lot for (tailored / handmade procedures). It´s currently not worth for the sim, due the cost value ratio but we will see what happened in the future. Never say never :slight_smile:

Cheers,
Richard

Appreciate the response, thanks! That’s fair enough.

I wonder if you could also comment on the LOC outbound IPKN for the missed approach at KASE. It doesn’t seem to be located in the right spot for whatsoever. Is this another one of these sim limitation issues similar to the offset LOC at LOWI?

Looking at IPKN in LittleNavMap, the localizer appears to be in the correct location in both the default sim nav data, and when using Navigraph. (The beam width is narrower in default). The localizer is located on a mountain peak at a ski resort south of the airport.

With both default and Navigraph, the localizer points “the wrong way” on the map (to the southeast), because an aircraft using this for the missed approach would actually fly the back course portion of the localizer which points to the northwest. On the approach chart, it indicates that even though it is a back course, it has “normal sensing” meaning that the left and right sides of the beam are swapped.

Normally when flying a localizer back course, the needle response is opposite - if the needle drifts right of center, you would fly away from the needle (to the left) to bring it back to center.

It is likely that the nav receiver in MSFS aircraft does not have the ability to handle a back course ILS beam with normal sensing.

One way of dealing with this would be to set the course on the CDI to the reciprocal of the localizer front course - i.e. 123 degrees instead of the published 303 degrees. This would only work with an HSI course indicator - it would not work with a simple GA-style OBS/CDI gauge where the CDI needle is hinged at the top and does not rotate with the course selector.

Unfortunately, even with a rotating HSI, all default Asobo aircraft lock the course on the CDI to whatever localizer course is contained in the nav data as soon as a localizer is within reception range. The HSI ILS course setting cannot be changed once an ILS is being received.

There is probably nothing that can be done in the nav data itself when using default MSFS aircraft to make this back course/normal sensing localizer work the way it is supposed to. When trying to fly it outbound, you would have to fly away from the needle to bring it back to center as if it was a “standard” back course.

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There is a similar situation at Memphis KMEM which is the the primary US hub for FedEx. There are several custom SIDS and STARS at KMEM which are literally “owned” by FedEx, and only available for company aircraft. These procedures are not published in a standard IFR chart subscription for KMEM, nor contained in any non-FedEx FMS AIRAC.

I’m familiar with the positioning, sensing and how to fly the procedure.

It’s all well and good looking at what shows on littlenavmap etc but the reason I bring this up is because when the procedure is actually attempted in sim, here’s what actually happens…

Notice the CDI and the actual track flown.

The data seems to have more or less correct course but its track over the ground I looks incorrect. And to make matters more confusing the CDI is showing that we’re not on the localiser :man_shrugging:

There’s some weird things going on at this airport. As mentioned earlier, the inbound localiser IASE seems to mysteriously disappear at 4.9 DME too.

Thanks,
Rob

The CDI shows you are left of course, but you are actually right of course, because (unlike the real localizer) the sim probably doesn’t support a back course localizer with normal sensing. From your screen capture it looks like it is acting like a standard back course with reverse sensing, so you would have to fly away from the needle (to the left) to get the right-deflected needle to center up and bring your ground track to the actual localizer centerline.

I doubt that the sim autopilot can intercept and fly this correctly in standard LOC mode. The MSFS G1000 does have a back course (BC) mode button, but I have never tried using it to see if it actually works.

If not, you would have to fly it semi-manually in heading select, turning to the right after the missed approach to intercept the localizer back course, rolling out on a 303 heading when the needle centers, then steering opposite to any needle deflection to keep it centered as you fly outbound.

The loss of the main IASE localizer at 4.5 DME is a mystery to me. I have not flown into KASE in the sim yet, but will give it a try to see if I get the same result. LNM appears the show the IASE localizer originating from the correct location.

Ah, you’re right, admittedly I did overlook that, assuming the sim doesn’t support that type of localiser. I suppose one doesn’t immediately presume that limitation.

However having said that I have tried to manually fly the localiser with the raw data, and flying left outbound doesn’t bring the needle any closer, only by flying right.

I wonder if hitting B/C then flying using HDG like you say may be the key to get this to work somewhat as expected.

Thanks for your input! Really appreciate it. I’ll give this a try tomorrow and let you know how I get on.

This is a real fun approach to fly in the CJ4 and it would be great to be able to properly fly it - if possible - as charted. At the very least if we can find out if it’s really not possible using the tools available then this can be raised as an issue and potentially fixed for us and everyone else.

And yep. Really can’t work out that one with IASE!

Thanks again!
Rob

I just tried the approach. You are absolutely correct - The main IASE localizer does indeed disappear at about 5 DME, as does the IPKN localizer - it vanishes just inside the point on the approach plate where it shows the right hand turn as part of the missed approach procedure. What is more, IPKN appears to be set to a course of about 150 or 330 degrees, not 303 degrees. After (unsuccessfuly) trying to do the missed approach as published, I turned right to due east, and flew until the needle centered, then turned to follow it outbound and I found the airplane tracking parallel, and just to the east of the main IASE localizer.

BC mode in the default G1000 appears NOT to work, and once you select it, regular LOC tracking no longer works either.

IPKN is acting like other offset localizers in MSFS when such offset localizers are linked to a specific runway, in which case the Nav receiver “sees” the localizer as having the runway heading despite how the nav data might actually define it.

Both IASE and IPKN disappear when you get closer to the airport than about 5 miles. Curiously, the IASE localizer CDI needle disappears, but the DME part keeps working

Very strange indeed.

This was with Navigraph active. I will try it again with default data later this evening.

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