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Radio Nav question

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Guest

Hi,When flying in VOR mode with the nav. radios set to manual, if I needto check the MAP mode, the setting goes to auto what is fine. The problem is when back to VOR the frequency tuned before as gone. I needto look to the chart, set Rad Nav to Manual and ajust again the freq,witch can be difficult on final.Is this correct or am I doing something wrong.thanksJoao

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Guest MB327

I rarely use the VOR mode so I won't be able to help here but there are a few of the guys out there who do. Perhaps Ian Ielchitz or someone can answer this for you.

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Guest

The 767 has a perfectly functional FMC that can do anything a VOR can do, but better. If you are trying to track VOR's for navigation, stop. If using VOR's/radials to navigate, just like you have done with MS default aircraft, I suggest some time with the PIC manual - Mike B can point out the relevant sections in his previous post.

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Guest

I think (I'm not positive) that this is due to a FS2002 limitation. The real 767 has multiple VOR and ILS receivers; FS2K2 gives you two navigation radios. The PIC team had to make some adjustments and I think you're experiencing one of them.That being said, if you need to track a VOR, it's usually easiest to just program it through the FMC and fly it via LNAV.Jon (KSEA)

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Guest

Thanks for your answers, butI am not sure if I explain my problem well. Please try this:If you are in MAP mode on auto, the frequencies will be set by thethe FMC.If you change to manual and set it to xxx.x freq, then you can gofrom auto and manual again and this freq will be always xxx.x (in manual)If you are in MAP mode in auto and change to VOR the setting willchange to manual but the frequency will be the last in auto mode notthe manual xxx.x.With some tests I found a way. If I set to manual in MAP mode before change to VOR I will still have the xxx.xWe just have to remember thisRegardsJoao

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Guest WorkingStiff

This problem is discussed in the 767 PIC team FAQ Section D #10: http://www.flightsimnetwork.com/efpanels/7...C/767PICfaq.htm"When on an ILS approach, my ILS frequency sometimes changes for no apparent reason. Changing the EHSI mode between the MAP mode and the VOR/ILS modes causes the NAV1 receiver to change between AUTO and MAN tuning modes (see the systems manual for an explanation). To avoid having the ILS frequency change during an approach, manually tune the frequency in MAN mode and then place the NAV receiver back to AUTO mode. This will cause the FMC to auto tune the ILS frequency so that both the AUTO and MAN modes of the receiver have the same ILS frequency tuned. Changing EHSI modes will thus not affect the frequency tuned."It was also discussed extensively on the old forums...here's an old post from Eric Ernst: http://www.avsim.com/cgi-bin/dcforum/dcboa...D43&archive=yes"Unexplained ILS frequency changes......Explained!!" Friends,Some users posted regarding unexplained ILS frequency changes during an ILS approach. Also, some have reported that the AUTOPILOT warning light comes on as well during an approach. Well here is the reason....the long version . It is partly a design "flaw" (if you will) that can be prevented procedurally.In the real aircraft, there are three separate nav receivers. NAV1, NAV2 and ILS. The NAV1 receiver is the one you see on the main panel next to the AFDS panel. NAV2 would be on the opposite side (we put it on the pedestal). On the pedestal would be an ILS receiver. NAV1 and NAV2 in the real plane can ONLY receive VOR stations. The ILS receiver can ONLY receive ILS stations. This was a problem from a sim design standpoint because FS only supports 2 NAV receivers. As a workaround, we allowed NAV1 to receive both ILS and VOR stations. The NAV1 will "auto tune" the ILS for you if it is in AUTO mode. You can also tune in the ILS frequency manually by placing the receiver in MAN mode. The problem comes in when you switch EHSI modes. If you are in the EHSI MAP mode and switch to an ILS or VOR EHSI mode, the NAV receiver automatically reverts to MAN mode. This is the way the real aircraft works because AUTO tuning is only available when the EHSI is set to MAP or PLAN mode. The problem is that the AUTO tuned frequency will be "switched" to the stored MANually set frequency (as it would in the real aircaft). This presents a problem on approach because if the manually set frequency is a VOR station, the ILS signal will be lost. This would generate an AUTOPILOT warning since the AFDS has now effectively lost it's navigation signal.Now. If you MANually tuned an ILS frequency, it will be stored in memory and the ILS will tune in. However, if you switch EHSI modes between MAP and the ILS modes, the tuner reverts back to AUTO mode upon return to the MAP mode. This is the way the real aircraft works. However, in our sim this presents a problem for those that manually tune in an ILS frequency and frequently change EHSI modes. I call this the design "flaw" since these problems are not encountered on the real aircraft because of the existance of the third dedicated ILS receiver.How do we prevent this??? Easy. When you are preparing for an ILS approach, MANually tune in the ILS frequency as a backup. Put the receiver back in AUTO mode and allow it to auto-tune the ILS frequency. This way, when switching EHSI modes, the ILS frequency will remain tuned regardless of whether the receiver is in AUTO or MAN mode.

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Guest Ian_Riddell

Now that's what I call an explanation! (grin)An epic in the making.Thanks, Stiffy.CheersIan.P.S. Just a clarification on the "receivers". There are actually 2 VOR receivers and 3 ILS receivers (on the real aircraft).... but only 3 control panels/heads. The traditional-looking ILS control panel (found on the real 767 pedestal) tunes all three ILS receivers at the same time (to the same frequency).The 747-400 also tunes all three ILS receivers at the same time, but via the Captain's/Co-Pilot's FMC CDU(s), not unlike PIC. It gets interesting though, when the FMC's fail (in real life).... You can still use the CDU's, but you now have the opportunity to tune the ILS receivers to 3 different frequencies/courses (as there are 3 CDU's on a 747-400).

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