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ILS

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Hi,I am working on a xml gauge and I wonder if it is possible get the following values;ILS ident, ILS frequency,ILS course and ILS-DME distanceBrgdsEugen

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ident, frequency and DME distance can be obtained from a tuned ILS from NAV1 IDENT,NAV1 ACTIVE FREQUENCY,NAV1 DME (or NAV2). I don't know if the localizer course is derivable from any of the other variables, at least for the "old" C-gauges it wasn't possible, maybe with xml.Are Bartels

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Hi Arne,Could this be used for ils course?((A:NAV1 OBS, degrees) dnor)%!03d! brgdsEugen

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NAV1 OBS is the selected course, not necessarily the localizer course. In reality you have to select the correct localizer course on the OBS though. In FS you don't need to select the correct course at the OBS, the aircraft will "find" the localizer course anyway. This is unreal, because (apart from FMC databases) the aircraft doesn't "know" the localizer course, it gets only left-right deviation information from the localizer (the same is true for up-down info from the glideslope).With the same argument RMIs that show bearing to localizers are also unreal, the VOR needles of RMIs can only show bearing to VOR, no bearing to localizers nor bearing to DME stations (maybe TACAN) available.Arne Bartels

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>In FS you don't need to select the correct course at the OBS, the aircraft will "find" the localizer course anyway. This is unreal, becauseHmm, don't agree (but correct me if I'm wrong), I think it is very real. When on a localizer the OBS setting doesn't matter at all, if I have understood it correctly. Setting it anyway, is just a matter of "good practice and a pilot reminder", and don't influence how the display works. That's why back courses are so easy to do with a HSI where one can rotate the whole "system". Maybe I'm just misreading what you're saying.Based on this, it appears to me that the to/from flag on default VOR indicators shouldn't be active during a localizer reception, since there exist no radials in the signal? Or is this a varying "function" depending on which reciever and/or display one is using?Also, on an RMI, the ADF pointer goes to a locked position when not recieving. Should the VOR pointer behave the same way or should it lock to a certain position on the rotating card (default Baron RMI)?But for the question. You *can* (although not realistic) calculate the approach course based on deviation error and bearing to station (I think) that the (faulty) localizer inhibit.

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Sorry it wasn't probably clear enough. For a manual ILS approach it isn't necessary to select the ILS course, if you know it. An autopilot though needs to know the ILS course to be able to follow a localizer properly, in my opinion. It might be possible that an autopilot is able to follow an ILS purely on left-right information, but it won't be able to align in the first place, if the aircraft isn't flown on the localicer manually before engaging the autopilot. What I wan't to say is, the way the FS autopilot is able to align on a localizer with a wrong OBS from big angles to the localizer (>45

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Hi guys,I have followed your discussion with great interest, sohave do I calculate the localizer course in degrees from deviation and bearing ?BrgdsEugen

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Oops, I didn't know that before, but (A:NAV1 LOCALIZER,degrees) dnorgives the localizer course without further calculations.(A:NAV1 RADIAL,degrees) 180 + dnor is bearing to the NAV1 station(A:NAV1 CDI,number) 127.0 / 2.5 *is the deviation if a localizer is tuned (127 full deflection equals 2.5 degree offset from localizer. VOR is different! It has 10 degrees at full deflection)So if a localizer is tuned and received, the deviation (CDI) is within -127,127 then the localizer course can be calculated with:(A:NAV1 RADIAL,degrees) 180 + dnor (A:NAV1 CDI,number) 127.0 / 2.5 * - , but of course using "(A:NAV1 LOCALIZER,degrees) dnor" is simpler and more precise. As stated in the other posts, in reality this isn't possible, since there is no bearing info available for localizers, luckily we simulate only, so we can.Arne Bartels

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