Jump to content
Sign in to follow this  
Guest JimC1702

How to determine if a backcourse approach, etc.

Recommended Posts

Guest DanWalloch

You will be assigned an approach, then you read your approach chart which you legally need. And a BC doesn't have glideslope, it's just the backside of the localizer that is feeding the other end's ILS or Localizer. Lastly, it's all in your instrument rating training.

Share this post


Link to post
Share on other sites

>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?The pax that the various news outlets interviewed had nothing but praise for the pilot and crew. What happen on the ramp at KGYY was obviously out of their control.At that time of evening it would take right at one hour to drive a bus from KORD to KGYY. That it took United six hours to get busses to KGYY is what irritated the pax and the crew for that matter!By that time everyone on the a/c had been onboard for at least 16 hours... They couldn't even allow the pax to deplane and stretch their legs.I am surprised that the a/c wasn't diverted to KMDW though. Perhaps remaining reserves were insufficient to get slotted into the already overloaded arrival sequence.


Fr. Bill    

AOPA Member: 07141481 AARP Member: 3209010556


     Avsim Board of Directors | Avsim Forums Moderator

Share this post


Link to post
Share on other sites

I am resurrecting this topic a week later to try and get it back on its original track and distill in one post what I

Share this post


Link to post
Share on other sites

I tied as hard as I could with the default crj-700 and default KALB, and never could get it to capture or show a backcourse. I took off in both directions and as I overflew the localizer the ident and sensing changed. Then I flew a racetrack parallel to the runway, and finally flew in perpendicular to the runway. In all cases the sensed ILS localizer switched back and forth depending on the end I was closest to. But using ADE to turn off the backcouse avail option on the ILS should fix the problem for good.http://forums.avsim.net/user_files/189767.jpgafter flyng back and forth across the perpendicular (reversing course after the ILS ident changed) Finally I flew for an approach to Rwy 19, and even selecting APPR on the A/P I had no trouble captuing LOC and GS.scott s..

Share this post


Link to post
Share on other sites

>>FSX is unable to follow the real world >model since it can

Share this post


Link to post
Share on other sites

Scott, thanks for trying this out. About all I can say is that my experience is entirely different from yours. Had it been like yours, I never would have posted in the first place. Using the default afcad, I have no GS for Rwy 19 at KALB. Furthermore, the only way I can capture the localizer for Rwy 19 using the autopilot is to use the REV mode. The APP mode turns me around 180 degrees. However, as you indicate, the idents for the runways do switch as you change direction. But I still wind up with a front course approach on Rwy 1 and a back course approach on Rwy 19. And if I use ADE to uncheck the back course boxes in the default afcad, I wind up with no localizer at all for Rwy 19. Why my experience should be so different than yours I just do not know.Thanks,Robert

Share this post


Link to post
Share on other sites

Jim, I will follow your suggestion and check the ADE forum. Perhaps I need to do something more than just uncheck the Enable Back Course checkbox in the default afcad.Look, I readily acknowledge that before making this post I knew little about afcads and the nuances of ILSs. Now, due to all the confusion - and my apparent misuse of Reggie Fields' analysis - I probably know even less. In any event, all I did in my original post was to make an observation about how the ILS's at certain runways at KALB and KPHX operated in FSX. Based on my observations, it appeared to me that when both ends of the runway use the same ILS frequency, the higher numbered runways function as a back course approach without a glideslope. How else can one explain that I needed to use the reverse sensing mode on the AP in order to capture the localizer for the higher numbered runways? What troubled me was that the real world charts did not indicate that these higher numbered runways were back course approaches - and are in fact not back course approaches.Now it seems that Scott for one has an entirely different experience with the runways at KALB. For him, apparently, both Rwy 1 and Rwy 19 work as front course approaches with a glideslope. I can't begin to explain why Rwy 19 works for him in this manner and not for me.Thanks for your assistance.Robert

Share this post


Link to post
Share on other sites
Guest PPSFA

Runway numbers have no bearing on the type of approach, and checking KALB in Airnav, Albany has no backcourse approaches at all, only ILS, LOC, and RNAV/GPS. This might be where you are getting confused?BTW, same for KPHX, with the addition of Visual approachesXP Pro SP2-FSX SP2AMD FX60-8800GTS-2 Gigs RAMFEX-GEX-UTUSA-FSGenesis-and a bunch of other stuffComputer optomized by www.fs-gs.com

Share this post


Link to post
Share on other sites

RobertAlways set yourself a standard to work with. For KALB use the default Cessna 172. Make sure there is no other KALB bgl on your computer somewhere and only the stock FSX airport is in use.I also checked KALB and everything is working correctly even though both Localizers are 109.50 and BC is checked. Like Scott's picture shows the BC for each end is nullified once the User plane crosses mid field (gets behind the Lat/Lon of the antenna).If you are using a 3rd party plane for your test, that can sometimes be a issue. If you have a enhanced KALB (some call AFCAD) that can be a problem if the Localizer data has been tampered with. There are Utilities available for FSX that can destroy Localizer data due to the way they scan in the XML code on a decompile. Always use a proven airport utility that is 100 percent FSX /SP1a /SP2 compliant and plays by all the correct SDK rules. There is only one enhancing airport utility that dose that. It is called Airport Design Editor(ADE).

Share this post


Link to post
Share on other sites

Jim, since reading your earlier post, and digesting Scott's experience, I've been doing a lot more testing. I think I've found the problem. It has to do with other custom afcads that I'm using that I've downloaded from Avsim. They also turn out not to have been made with ADE, just as you indicated might be the case. So your latest suggestion hit the nail on the head - and I am very thankful. Here's what I found.I was not using a custom afcad for KALB or KPHX. However, if I disabled all custom afcads that I've installed, then I no longer have the problem I've reported. In other words, runways using the same frequency now have front course localizers with glideslopes, if available, at both ends. No more back course behavior at KALB and KPHX on the higher numbered runways. So the problem apparently was being caused by other custom afcads having nothing to do with the two airports in question. I suppose by trial and error I could determine which particular afcad or afcads are causing the problem, but I'll have to decide whether it's worth it.What started me on this path - along with your and Scott's posts - was a post I found on the AFX forum (which I looked at after checking the ADE forum) where a guy had the exact problem I was encountering, but he was having it at EGNX. He solved it by changing the frequency but that's not what I wanted to do. I gave the airport a try - and it worked for me just as KALB worked for Scott, and now you too. I have no afcads installed for that part of the world, and so I decided to disable all my custom afcads and give KALB and KPHX another try. I had just finished doing this testing when I got your latest post. So an afcad having nothing to do with the airports in question appears to have been causing my problems. Thanks again to you and all the others who posted for the assistance.Robert

Share this post


Link to post
Share on other sites

>How else can one explain>that I needed to use the reverse sensing mode on the AP in>order to capture the localizer for the higher numbered>runways? Robert,This probably can be explained by watching your procedures. In order to get behavior like in Scott's diagram you have to always switch the course (to runway 01 or 19 in this example). If you don't do it you get this 'backcourse' behavior - in my opinion you can always get backcourse sensing if you mismanage your course setting. So the key is to know where you are in relation to the runway at ALB (which 'side' you are on) and what is your course setting.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

Share this post


Link to post
Share on other sites

I would be interested if you could nail it down to a specific bgl file causing your behavior.scott s..

Share this post


Link to post
Share on other sites

Ok, Scott, after extensive testing I have determined the source of the problem at KALB and KPHX - at least on my system.The ILS for Rwy 19 at KALB is being interfered with by several of the northeast airports created by Jim Cook and listed at Avsim. Only one of his airports doesn't give rise to this problem, and it is KGFL. Jim's plain civilian afcads (as opposed to the full airports that he does) do not pose a problem at KALB; nor do his military afcads (but see below for more on the military afcads).The ILS for Rwy 26 at KPHX is being interfered with by one of Jim's military afcads. I have not bothered to determine which one is the culprit since there are so many, and have just disabled them all. I should also note that there may be a conflict here between one or more of Jim's military afcads and other software I am using at KPHX. I use the Megascenery for Phoenix and Ray Smith's KPHX afcad. I have not tested Jim's military afcads against the default KPHX.Jim's work may affect other airports with runways where both ends use the same ILS frequency, but I haven't encountered any yet. So be forewarned.I am letting Jim know about these problems and perhaps he can remedy them.Robert

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
×
×
  • Create New...