On the flight deck of 757 last week I noticed that the NAV1 & NAV 2 Auto & Manual tuning can be independent.For examplethe NAV 2 box was tuned to TRN VOR 117.50 CRS 189 in Manual Mode, but switched to GOW BOR 115.40 CRS --- when selected in Auto Mode.When the Auto/Man switch was pressed again the TRN VOR reappeared.The Nav1 box was tuned in to the GOW VOR CRS 234 in Manual, and again displayed dashes when selected in Auto Mode.I tried this in PIC, but when swithcing back to MAN mode, the VOR remained tuned to what ever the last Auto Tuned Station was.How does the real NAV unit accomplish this.Mark

Hmm, not sure what you are asking, but I'll see if this helps. I hope I am not being too basic....First, the actual radios are a black-boxes on the rack below the flight deck. What is on the glare shield is a "control head" that sets the frequency for Nav 1 (left) and Nav 2 (right). The FMS has that same capability. The radio box determines if it is Auto (FMS/IRS) or manual then selects the freq that it is supposed to.Also, you can "hot swap" freq in manual mode. You can dial in a new Nav freq but the old one stays active till you press the selector "In". Eric's original panel did that, but not in PIC767.Timothy

When in auto mode both VOR radios will dial up various VOR/ILS/DME in order to radio update the FMC position.When you press manual it will return to the last manually entered frequency. When you press auto again the radio will tune to whatever frequency it feels like.The radial selected will stay the same in auto or manual, and is never changed by the fmc in auto.

Does it use ILS frequencies too for position updating? Isn't that a separate receiver?Martin767 fetishistIt's a lot like life and that's what's appealing

Yep, my mistake!The FMC can use the VOR/DME and ILS radios for position updating. However as you point out the ILS reciever is totally separate in the real aircraft!

I only knew it used VOR and DME for position updating, but a quick dig in the manual confirmed that localizers are also used. It says that the POS REF page 2/4 (PIC only has 3 pages BTW) shows different combinations of LOC, RADIO and GPS, and of course IRS. I have only seen RADIO and IRS in PIC. It seems PIC only uses VOR/DME for position updating, and not ILS localizers.Martin767 fetishistIt's a lot like life and that's what's appealing

Given the limitations of FS, this makes sense. On the real bird, I believe there are three VOR receivers and three separate ILS receivers. It'd be nice to have more radios in FS to make tuning a bit more realistic for heavies like this.Ah, Flight Simulator 2002...in some ways so advanced, in other ways it's still the same program it was 15 years ago.Jon (KSEA)

"On the real bird, I believe there are three VOR receivers and three separate ILS receivers."I think the latest poll puts the number at:Two VOR-Marker Receivers (but the Marker is only active in the Left Receiver because of equipment rack "pin programming".Three ILS Receivers or three "Multimode Receivers" (MMR's). MMR's have GPS circuits in them as well as GS & Loc.The ILS mode control panel on the real aircraft tunes all three ILS Receivers at the same time (to the same frequency/course)http://www.ozemail.com.au/~iriddell/767/ILSControlPanel.jpgCheers.Ian.