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Guest JimC1702

How to determine if a backcourse approach, etc.

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I need some help understanding how one does the following two things when setting up an instrument approach:1. How do you determine - in advance of the landing - that you will be making a backcourse approach? From my review of the various approach documents available to me, it appears that the only way to get this information is to call the Tower before landing. If that's how one is supposed to do it, so be it. But I would think you should be able to ascertain this information from the airport documentation on line. For example, I have recently encountered what appear to be backcourse approaches at KALB, Rwy 19, and KPHX, Rwy 26. Both runways use the same ILS frequency as their respective reciprocal runways. Yet, if I examine the approach plates for each runway and its reciprocal, I can find no indication as to which runway - in the case of KALB for example - Rwy 19 or Rwy 1 is the backcourse. The only way I seem to be able to determine this is to activate the APP mode on my autopilot and if the plane veers off to the right I know it's a backcourse and I have to also activate the REV mode on the A/P if I wish to use it to follow the localizer. I guess I find it surprising that there is no approach documentation that provides this information and I would hope that if such documentation exists, someone could call my attention to it.2. How do you determine - in advance of the landing - when you know you are making a backcourse approach, whether it has a glideslope?In this situation as well, I can find no information on the approach plates for the runways specified above whether there is a GS. The only way I've been able to determine this is to actually fly the approach and see if the GS comes alive. Oughtn't this basic information be available to a pilot in advance in the approach documentation, and if so, where?Thanks for any assistance on these issues.Robert

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>1. How do you determine - in advance of the landing - that you>will be making a backcourse approach? In real world? While flying IFR you would get this information before contacting tower, it would either be some sort of ATC approach facility or even Center which would tell you what approach to expect. Very often you have to fly transition routes which are hooked with specific approach so you would normally know about it way before contacting tower. Approach is normally predicated by winds/runway in use.Bear in mind that ATC in FSX has many limitations and shortcomings. For better ATC fidelity you should use a product like Radar Contact.>I can find no indication as to>which runway - in the case of KALB for example - Rwy 19 or Rwy>1 is the backcourse. I am not sure what you are asking. Every backcourse approach has independent approach plate. You can **NOT** use an ILS/localizer approach plate for some runway and then try to use it for a backcourse approach to opposite runway end, it doesn't work like that. Look for specific backcourse approach plates - if one doesn't exist it means this approach doesn't exist. For example unless I am missing something I don't see any backcourse approaches at KALB or KPHX.Please bear in mind that for example in case of KALB runways 19/1 - in real life only one approach would be working, only one would be turned ON. This is a problem in FSX that all approaches are turned on all the time.>2. How do you determine - in advance of the landing - when you>know you are making a backcourse approach, whether it has a>glideslope?Backcourse by definition is always a localizer approach so it NEVER has glideslope.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

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Michael, thanks for the input. I may not have been as clear as I might have been. Let me present each question again with some more detail.1. ATC is not an issue. Let's assume I'm not using it. I'm out flying around. I could be near Albany or Phoenix. I choose to land on Rwy 19 at KALB or Rwy 26 at KPHX using each's respective ILS. In both cases I find that if I activate the APP mode on my A/P, the plane veers to the right and turns 180 degrees. I am assuming that this means that these are backcourse approaches. The only way I can land using the localizer is to also press the REV mode button on the A/P. Also, each runway uses the same frequency as its reciprocal runway. It is on the basis of these facts that I have concluded that Rwy 19 at KALB and Rwy 26 at KPHX are backcourse approaches. Am I mistaken in analyzing this data?What I want to know is whether I can determine in advance from the airport documentation (as opposed to when I'm trying to capture the ILS) that these runways are what I believe to be backcourse approaches? The approach plates for each backcourse runway and its reciprocal use the same frequency but different identifiers. And except for the obvious differences in waypoints, directions, etc., the approach plates describe the approaches identically, i.e., there is nothing - to me anyway - to indicate that one is a backcourse approach. Assuming I am correct that one of the approaches is in fact a backcourse approach, how is one to know this from the documentation for the airport and its runways?2. My research indicates that backcourse approaches can in fact have their own GS or use the one from the reciprocal runway. See http://stoenworks.com/Tutorials/ILS%20Back...Approaches.html. What prompts this second question is that from reading the approach plates for Rwy 19 at KALB and Rwy 26 at KPHX, I had no reason to believe that they did not have glideslopes. But they don't and I consequently overshot them. And my question is ought not one be able to determine this before making the approach from the documentation available?Thanks again for your input.Robert

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>In both cases I find that if I activate the>APP mode on my A/P, the plane veers to the right and turns 180>degrees. I don't know how you approach the airport, what airplane/autopilot you use, how you set up for approach, etc. so it is difficult to get an idea what is going on. Try to use some quality add-on aircraft with proven autopilot. Also you procedures can be wrong. I simply don't know.>I am assuming that this means that these are>backcourse approaches. Reverse sensing often means "backcourse" but it can also happen if you set it up incorrectly, you are in the wrong place in respect to approach. Again, what I said above.>What I want to know is whether I can determine in advance from>the airport documentation (as opposed to when I'm trying to>capture the ILS) that these runways are what I believe to be>backcourse approaches? Again, if approach is backcourse it says so in bold letters right at the top of the approach plate - in the name of the approach. Unless it says "BACKCOURSE" or "BACK CRSE" at the top of the page it ain't so.>runway and its reciprocal use the same frequency but different>identifiers. Like I said before - in real world only one end of the runway would be working.>2. My research indicates that backcourse approaches can in>fact have their own GS or use the one from the reciprocal>runway. See>http://stoenworks.com/Tutorials/ILS%20Back...Approaches.html.Yes, I see but no, it is not GS. There is no glideslope on this diagram. Don't confuse step-down with GS. If this author claims that there are backcourse approaches with glideslopes he should have given you an example. I don't see any here. I think he may be dead wrong here. That's the nature of internet - you can trust only well know sites.>What prompts this second question is that from reading the>approach plates for Rwy 19 at KALB and Rwy 26 at KPHX, I had>no reason to believe that they did not have glideslopes. But>they don't ...?? they do have glideslopes. You can either fly a full ILS at KALB rwy 19 or fly only LOC to this runway. I think you need tutorial how to read/understand approach plates.>And my question>is ought not one be able to determine this before making the>approach from the documentation available?I suggest you read some tutorial on IFR flying because you have major misconceptions how it all works. This is a highly technical area and is full of pitfalls for novices.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

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Ah Robert I see your issue.1. Runways that have the same freq on both ends of the runway have only one turned on at a time so don't let that confuse you. EITHER ILS 1 or 19 is in use and the ILS transmitter for the active runway is the only one on.2. KALB shows LOC/DME OR ILS/DME which is why you don't find a glideslope only a localizer. FSX probably modeled the LOC approach but not the ILS approach. You must fly the approach manually (KALB doesn't have the capability for autolands anyway).Neither of these runways are backcourse since backcourse approaches explicitely says...backcourse.

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Ok, Michael and MIke, so I conclude that these are indeed NOT backcourse approaches and that my inability to capture the localizer without using reverse sensing may be due to pilot error. I will check my procedures again. Also, there may be some kind of corruption of my system as well, as I recently installed the Reality XP Garmin 530 and that installation or its settings may be the source of the problem. The problem exists, however, not only with the RXP unit, but also with the default GPS, and, at KPHX anyway, the PMDG 747.Thanks for clarifying how one identifies a backcourse approach. At least I'm clear on that now.Robert

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I don't think there are that many true "backcourse" approaches IRL. There are some interesting things, like at Juneau, where you fly outbound on the departure on the localizer reciprocal.In the case of KALB, I looked at the FAA database for AVN (this is the flight inspection office which flies instrumented aircraft along the ILS signals to verify their performance).For ALB, it uses a log-periodic array antenna with a single Mk20 transmitter. For DEJ, it also uses a log periodic array antenna but with dual frequency, dual Mk20A transmitters. (Dual frequency provides for a wider localizer "beam" signal to help ensure correct capture.)Log periodic antennas have a characteristic that not nearly as much energy is transmitted in the backside direction. Thus, IRL, getting a reliable signal in the reverse direction is not likely. Of course, FS by default enables the backcourse signal on all localizers. I've never had a problem with capturing the backcourse rather than the proper frontcourse when the ILS localizers are using the same frequencies (there are only so many frequencies so FAA likes to conserve them. As stated up thread, there is a requirement for a switch over in the tower to prevent both systems radiating simultaneously, except for certain maintenance conditions.) But I've seen many posts from people with that problem, so accept that it does happen.scott s..

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If you want to know if a FSX airport has a Back Course then simply look at the default GPS receiver for the airport that will be your arrival. There are many Airports that still have a Back Course for their runways. Go to Airnav and pull up KCLL which is Easterwood in College Park, TX. Download the RWY 16 Back Course Chart and study it.Once you have done that now position your plane at KCLL. It is best you use a FSX default plane with the proper GPS receiver that came with FSX. Open the GPS receiver and/or select KCLL if you are somewhere else. The very first approach in the list is the BLOC 16 with vectors to final and 3 additional Transitions (not shown in the pic) as per the Jeppesen published charts.http://img48.imageshack.us/img48/7831/bc1xz7.jpg[/img][/url]Anytime you see BLOC in the GPS receiver that is a Localizer Back Course (BLOC) approach. All the world BLOC's as of the backdate that MS read from the Jeppesen charts are coded in the FSX approach database and look like the following

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geofaI opened up one of my Jepp manuals and just thumbed through some airports until I found a Localizer BC. Both the airports you listed (KPTK, KAZO) have the BLOC also in the FSX GPS display so the User can Load and Activate the BC and practice flying them. See post below

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It is a good thing that they are still used! Last night, a United A320 made two attempts to land at KORD and had to G/A twice because of extreme crosswinds.The pilot diverted to KGYY and used the BC approach to Rwy 12. United dropped the ball though and didn't ask for the terminal to be (re)opened (it closes at 10pm when the tower closes), the poor pax had to remain onboard for over six hours while busses were sent from KORD to pick up the pax and baggage......the pax were not happy at all!

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Always strikes me strange though-would the pax prefer to be dead?The crew obviously made the right decisions to have a safe outcome to the flight. How can anyone complain about that?I did recently witness a buddy pass passenger go ballistic because their flight was overbooked and they had to wait another hour for another flight. I was flying for free at the time too and didn't consider that to be a big deal since it was FREE...go figure!http://www.mediafire.com/imgbnc.php/1b5baf...b9f427f694g.jpgMy blog:http://geofageofa.spaces.live.com/

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>Yes they do. My point was they are still used irw! I use mine>all the time. (Can't say I'd prefer an ils but the winds>commonly blow from the west here-kinda makes you wonder why>they chose the ils to be rwy 9 at my airport).>The ILS at KPTK is shown by FAA as having a VRING-15 antenna for the localizer. The V-ring assembly does, in fact, radiate significant energy in the back course direction compared to a log-periodic antenna. FAA says the backcourse usable distance is 14 nm vice 18 for the front course.scott s..

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