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Bigmack

SU2 course following

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For some reason my last 2 flts the FMC is off 10-15 degrees from flt plan. I built my plan with FSBuild2 and exported to FSnav and PMDG. The correct route shows in the color mengenta on the display but the FMC won't fly the exact course. Also when landing when I press the Nav|loc button, the AC intercepts the localizer then fly right pass it. It won't hold on the localizer. But it will follow the glidescope down. Even when the glidescope starts to desend, I press the apr button, the AC still won't follow the localizer.Bill M

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Bill -Actually, the FMC is right, and the ND is wrong. On longer routes, about 60 nm or bigger, the error becomes large enough to see. Basically, the FMC calculates the correct routing(great circle), but the ND draws something different, a straight line not taking into effect the great circle route.

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So what shold I do. ATC is constantly tell me to change my course when in the v-nav mode. Does this also effect the localizer when trying to intercept??Bill M

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Also if the FMC is correct, why do FSNav show different headings than AC FMC if I use the same flt plan??? ATC constantly corrects me the the FsNav heading, not the v-nav.Bill M

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There is something wrong with the FMC and ILS tracking. Please do not insult my intelligence by saying this is normal. I flew your previous version with no problem with ND plan mode or ILS tracking. I'm not trying to sound harsh, but there's a problem. Please don't ignore me. Again there is a problem. Lets work together to solve it.Bill M

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Bill, I am not so clear on your issue, I do not use FSNAV so have no idea what's going on. I think I understand what you are saying but you would do us a favor please if you say a few lines more about this. I'm not asking you to beta tester here sir, but a detailed listing of the issue you are having, what programs other than FSNAV you are using etc etc would be a great help. As to you mentioning ATC telling you to correct your course, are you not flying your own route at this point (LNAV)? If ATC wants me to deviate from my original route then they provide VECTORS for me to follow. If it's a DIR TO, this is simple matter for me to stay in LNAV or intercept a RADIAL etc. Otherwise I do what pilots do, go HDG SEL. Maybe I did not understand your post on that one. For ILS, what is it not doing correctly? I seem to be able to nail the ILS for any apporach I try. This does not mean that you are not having a real issue though so again please give us details, what ILS approach etc, give enough details for us to reproduce. Thank you Bill.[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/betaimg.jpg

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When I create a flt plan using FSBuild or FSNav, save and export it to PMDG plan and try ti fly the route, The ND display and the Heading course from the 737 FMC are off 10 to 15 degrees. I 'm not sire if the Fmc or the ND are fly magnectic heading or true heading. But I should not have to keep correcting my course when flying in V nav mode, It shound fly the plan route. I did not have this problem in the SU1 ver. What ever plan riute I put in the FMC it fkew precislly and showed correctly in the ND display.Also when doing an ILS landing, I have correct course setting, Correct runway freqs, but the AC will not follow the localizer or do a partial intercept wheither the loc or the Apr button is depressed. The heading and course is off 10 -15 degress, just like the problem flying the plan. Every ILS landing that I made since this new SU2 upgrade, I have to take over the landing because the instraments are off.Again this was never an issue in the earlier SU1 ver why is it an issue now??Bill M

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Here is a pic Attachment. Flting to peper isec I shold be at heading 279, which is the correct course. The 737 FMC using vnav mode flies the heading of 302. I manually set 279 on the MDU and ND displays 281 and the mengenta map is off almost 20 degress. That's the problem I'm having and it effects the auto pilot ILS landing.Bill Mhttp://forums.avsim.net/user_files/53709.jpg

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Bill,From that screenshot there I see straight away why you're having problems.Why are you letting the FS Navigator AP fly the aircraft?? Look at the FSNav FMS and you can see it has a heading of 279 to PEPER and that's what it's dialled into the MCP. For the aircraft to follow the PMDG FMC flightplan you must be in LNAV (not v nav as you describe) mode. Engaging VNAV will let the AP control the vertical profile as well.Are using the same AIRAC cycle for both PMDG & FSNav? Might explain the heading differences.

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No I'm not letting FSnav fly the AC. It's only monitoring the vor radio. Besides your autopilot don't accept input from FSnav anyway. The only thing I use FSnav to do is create flt plan. L nav is what I'm having a problem with. As far as the airac cycles, it's what you guys posted.Bill M

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Randy - great circle problem? Look at the distances between the fixes... could be.Ryan

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Sorry Bill but in the screenshot you posted FS Nav is definitely *trying* to fly the aircraft. The 'Fly Flightplan' tab is green signifying the 'Fly AP' button is depressed.Now whether you meant to press the button is something else ..

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Why is it difficult to understand. Fsnav cannot fly your AC. The green button is depreesed to monitor and change radio freqs. Nothing else. I was trying to show in the pic, in order to fly the AC on course to the correct heading the heading select button had to be selected. When Lnav is selected the AC flies the incorrect course. Which is the same flt plan that's inputed to FS2004, FSnav and 737 FMC. Is there any way to get back the SU1 version?? Then I won't have to bother you anymore.Bill M

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Hello again Bill, I'm sorry this is not working out the way you had it in SU1-1, like I said in my first responce to you, I do not use FSNAV, but just to understand this conversation I came across this statement on thier web site under this caption "How does it work?" "Now the interesting bit. Put in your flight plan route, go back to FS and take off. After you are airborne and have the gear and flaps up engage the autopilot. On the left hand side of the screenshot above you see a group of grey boxes - one of which is labelled Fly FP. If you now select this FSNav will fly your flight plan - completely automatically. It will climb to the right levels, set the correct speeds (it even knows to reduce below 250kts below FL100) and follow your route to perfection. On approaching your destination it will position automatically for the runway selected and gradually descend and reduce speed to the touchdown value for that aircraft. The only thing you need do is lower gear and flaps.... and taxi in after FSNav has landed your aircraft..." http://www.homepages.mcb.net/bones/04FS/fsx/fsn.htm This IS a problem Bill. Seems your statement "Why is it difficult to understand. Fsnav cannot fly your AC" is incorrect? Anyways you desire to be happy with how you want it to work, that's perfectly ok. If you have the original EXE (and four W files) you can install that and Su1-1. Did you happen to save those? I might have SU1-1 around, will have to check. I would aslo invite you to bring this question up to the Developers of FSNAV and see what they have to say, I am sure you are not the only one who uses the two? Thanks.. [h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/betaimg.jpg

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Yes, FSNav is a rather remarkable little program which was really helpful in FS98/FS2000 days when FMCs weren't the "norm". Its still helpful today with some freeware aircraft that doesn't have any FMCs. You can even program a Hold in you route and FSNav will fly the hold perfectly for you.Now, I know that CaptainSim deliberately removed all functionality with FSNav and their 727, therefore the Fly Flightplan button has NO effect on their 727. However, I'm not sure if PMDG has done the same. So although you think that it may not be having an effect, its possible that it could be. Its certainly an avenue to consider.Note also that, besides Randy, who is the lead beta tester, the only other people that have answered your post are customers. You are not bothering anyone. I know its easy to get fustrated when such serious problems crop up but its at times like this that one should remain calm and focused. I'm sure that your problem will eventually be solved. SU2 has too much enhancements to even consider going back to SU1.1Hang in there.

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I guess I'm getting fraustrated because you guys are locked on the issue about FSnav. For the third time FS Nav don't control the AC. I have programmed it to stickly to change radio freqs. And monitor my Flt path. Nothing else. I've used both products long enough to know how they operate. PSS has a simular auto pilot system as PMDG in their Airbus. And I flew the same exact route useing the same exact flt plans and it flew the correct course and landed with no problems. No I don't have the orginals. Please look and see if you have them.KindlyBill M

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Bill,First off, you're not bothering anyone (Randy can just get cranky at times ;) :D ) - we are here to help and this definitely has my curiosity up since I own FSNav as well and never saw anything like this during the beta.Can you mail me the exact route to load into FSBuild along with a description of the exact steps you're taking to reproduce this right from loading FS? My email is TabsAZ@aol.com I do want to point out however that you are mistaken as to FSNAV's "Fly Flightplan" button - on aircraft that use the default FS autopilot, this takes over the autopilot controls (like HDG, SPD, ALT, VS) and commands them to get the desired lateral and vertical flight path. It's sort of a poor man's FMC if you will... Judging by the pic though, it doesn't look like pressing that button is causing this issue.Email me those files and I'll post back with what I find out... Trust me, you DO NOT want to go back to SU1!!!

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Bill just to let you know I had the same problem in the original release back in August, for some reason when I installed SU1-1 they all went away. I Tried re-load after re-load with the original but it was still there my personal opinion is that I originally had a problem with my first install and after the complete removal prior to SU1-1 I had zero problems tracking an ILS. Just my $.02.

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I don't have the exact same SU2 behavior as Bill is describing, but I too do see that sometimes the heading being displayed by the ND is not the actual heading the aircraft is flying.http://www.fsbuild.com/dl/pmdg7377navdisp.jpgAs you can see in this screenshot, the aircraft is flying heading 180, but the Navdisplay is only showing heading 177.Something else I noticed too, is that when making a left heading selection the aircraft turns past the HDG SEL course then has to turn right to correct itself. But either with a left or right turn it seems to stay 3 or 4 degrees off from the actual heading.Perhaps this is a symptom of the same issue that is affecting Bill ?Regards.Ernie.

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PSS had this problem wih their A330/340 series. It was caused by the AIRAC file (can't remember which version) having been compiled without taking magnetic variation into account and taking all headings from "true north" instead of "magnetic north".Try downloading the latest AIRAC cycle from www.navdata.at and see if that solves your problem.

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Hi,Ernie, those pictures look more like you are affected by winds. Coming from the right at 20 knots you get a deviation of between HDG and TRK of approximately 3

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1. If anyone who knows how to use FSnav, knows that it can be programed not to fly the AC but simply monitor the flt plan and change radio freqs. If you noticed on my screen shot the M1 button is depressed and thats the only function it has to moniter the plan. If press the button below it(M2), it's programed to take over FS based Auto pilots to fly and land or what ever inputs you decide to put in. I don't use FSnav auto pilot features with PMDG or PSS AC because I know it won't work. And up to this point the FMC's has been so accrurate, FSnav is only used to create flt plans and monitor them. Or I use FSBuild to create flt plans and inport them to FS nav and PMDG. The problem is my PMDG 737 is not flying the correct heading wheither I use FSnav or not and even though it aquires the loc on landing for some reason it won't lock on and I must manully land the plane.2. I have not had this problem until the upgrade. The 737 flew the sid, stars and approach landing without a glitch. Again wheither FSnav was used or not.3. Do anybody have ant older Airdac cycles I can load to see if that is the problem. Because like I stated before I'm not sure if the AC is flying a magnectic heading or a true north heading, but according to the ND display, something is off 10-15 degress.I will email you the flt plans I used. But like I said before I flew the same flt plan with PSS Airbus and monitored With FSnav and had no problem.Bill M

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