Hi All, I was just dreaming along looking at pictures of NG cockpits at airliners.net. I stumbled on the picture given in the link below and noticed something that caused the following question: How many radios does the NG have? It can be seen from the ND that VOR2 is not tuned or at least not receiving anything at the time of the picture. VOR1 has been tuned by the FMC (or rather, I assume that is what the FMC indication means). On the PFD, another frequency to a station is displayed along with a DME indication that does not match the one displayed on VOR1. Can any of you pros out there explain that?With thanks in advanceBoazhttp://www.airliners.net/open.file/387764/L/

Boaz,I can only guess, but I would say that VOR2 seems to be tuned to Montpellier (LFMT) as the nearest suitable airport (for emergencies).GreetingsThomas

Hi Thomas, If that was the case, wouldnt that show on the ND?Boaz

> If that was the case, wouldnt that show on the ND?I don't know, as I said, it was only a guess...:-hmmm Let's the pro's answer that one.:-) Thomas

Hi Thomas, Hi Boaz,it took me quite a while to figure out what's happening in the picture. ;)After some thought, I'm pretty sure that the FMC has the approach into LEPA (Palma de Mallorca) loaded, namely runway 24L. Therefore, one navigation radio is autotuned to 109.30 already. Both, ILS frequency (109.30) and front course (240

0. Hello, PS1, please sign your real name on this forum, thanks! The 737 NG does not auto-tune, not in real life and not in this sim ;)[h4]Best Wishes,Randy J. Smithhttp://img.villagephotos.com/p/2003-5/196432/winglets_lg.jpg

"Can any of you pros out there explain that?"This phenomenon was highlighted recently on another website, Boaz, although I can't remember which one (Bluecoat? smartcockpit.com?). Note, at this point, I'm not 100% familiar with the NG FMC navigation processes, but this what I think was being said on the other site....The VOR's on the NG are not autotuned (known fact), but the DME's are autotuned (as well as being manually tuned, I believe). This VOR/DME manual/autotuning arrangement can lead to some strange indications on the 737NG ND. If the manually-tuned VOR is in range, the FMC may not necessarily autotune the DME associated (co-located) with that VOR. This may be because:1) The co-located DME isn't functioning.. or perhaps there isn't even a co-located DME (Sometimes there are VOR-only stations).2) The FMC may compute that two different DME's will provide a better fix than a co-located VOR-DME fix.Note that each DME Interrogator (there may be two or more of them), can, at the request of the FMC, autotune multiple stations and analyse the incoming data from four of these stations.... as well as analyse incoming data from a manually tuned DME. Even if there was only one DME interrogator functioning, the FMC could still get a DME-DME fix.In the pic, the identification of the VOR is shown below the annunciation "VOR L" as "TOU". This indicates that the VOR station is in range and the incoming morse code audio has been decoded by the VOR receiver. You can't see the VOR "TOU" on the ND as it is outside the range of the current ND scale, but, nevertheless, the signal is strong enough to be used if required. If the signal wasn't strong enough, "TOU" would not appear and you would simply see the manually selected VOR frequency below "VOR L" or "VOR R".Hope this makes sense? :-)Cheers.Ian.P.S. The green "FMC L" shows where the ND map is getting its position information from (The left FMC, in essence, is painting the map display on the ND). Sometimes there are two FMC's on a 737 and you can select which one you wish to use. You may see "FMC R" instead.P.P.S. BTW, there is an FMC page which is not currently modelled in PMDG's 737NG which gives you information on all the stations manually and automatically tuned by the pilots/FMC.

Please ignore my answer, Boaz.... I misread the question (It's been a long day) *:-* I thought you were saying that VOR L, tuned into "TOU", didn't have the correct DME distance for TOU (I missed the part about the PFD).As previously suggested, the R VOR/ILS panel is tuned to an ILS frequency. The ILS has an associated DME by the looks of things. Perhaps the VOR R is not displaying anything (frequency, ident or DME) because it is tuned to an ILS station (?).Cheers.Ian.

...just interested...which page of the FMC are you referring to, Ian?Cheers,Stefan

Well whats going on is that nav 1 radio is tuned to the TOU vor and the nav source info on the PFD is comming from nav 2 radio by way of the nav source transfer switch on the overhead. Thats the only way the display can look this way.

I beleive Ian was referring to the nav status page that show the freq scanning DME/VOR's that are used by the FMC for pos updating (this info is not displayed in the efis CDS display ,is ony shown on the FMC nav staus page.)

"Well whats going on is that nav 1 radio is tuned to the TOU vor and the nav source info on the PFD is comming from nav 2 radio by way of the nav source transfer switch on the overhead."Sorry, Wallace... I don't understand the significance of the Nav Transfer Switch in your answer. Is it not in the NORM position? Being the F/O's displays (in the pic), isn't the ILS data on the PFD simply coming from the onside (#2) MMR? The #2 VHF Nav Radio panel, I presume, is tuned to an ILS frequency.Thanks.Cheers.Ian.

Absolutley Ian your correct , I failed to notice Im on the FO's side. This would only be true from the pilots side.

Hi Ian,a 'dump' question here (I'm trying to learn more about the NG), what's the MMR? Multi Mode Receiver?Thanks, Markusp.s.in an unrelated question to Wallace - Wallace, would it be possible to contact you in private email on a VSD related question? That would be much appreciated.

Sure Markus reach me at [email protected]