Hi All, I have a question for the pros: I was flying along enroute to LGSA that according to the charts I have has a VOR DME approach. How does one fly that in real life? I assume you find your approach speed and the from the decend rate table interpolate to get an approximate vertical speed and when passing the FAF you set the MCP to V/S mode with the determined V/S. Is that correct? For some reason I could not get the V/S mode to work. No matter how many times I pressed the V/S button on the MCP it would not go into V/S mode. Thinking that I could master the airplane by hand, I switched off the autopilot and hand flew the approach (landed ON the runway but not to the liking of the technical judges :-lol). With thanks in advance, :-waveBoaz

Well, a usual non-precision approach like a VOR/DME, an NDB, or a LOC or LOC BC, works by using step down altitudes. Basically the plate will show you different DME fixes as you fly a particular VOR radial toward the airport - as you pass these DME fixes (and by fixes, I don't mean something that's necessarily in the FMC database, I mean a particular point in space defined by the distance to the VOR from that point on the radial - like TUS303/5, which would mean 5DME from the Tucson VOR on the 123 radial) you're authorized to descend to a lower altitude as terrain permits. After you reach the end of the approach you should have the runway in sight and be able to land visually, otherwise you have to decalre a missed approach.If you want (and I haven't tried this on the NG yet though, but have many times in 767PIC) you can program this kind of approach into the FMC, and provided the logic works, it should be able to fly it in LNAV and VNAV mode. You'd do it with the place bearing/distance fixes I was talking about earlier - so the full approach might end up looking like this in the FMC:These fixes are in the FMC database, but I'm going to assume that we're not using the database and we're going to actually build the approach using custom waypoints:KTUS VOR/DME RWY 29R: http://www.myairplane.com/databases/approa...US_vd_tr29R.pdfIAF (Initial Approach Fix) is SULLI, which is defined as the TUS 107 radial at 20DME, so enter into the FMC LEGS page:TUS107/20You should see TUS001 or something similar appear when you click it in on the left side. Assign a speed/altitude constraint of 210/8000 to this fix on the right side of the LEGS page. Next we need to fly a short 20DME arc toward the ILEEN fix staying at 8000 feet due to terrain (the foothills of the Rincon Mountains specifically) Create three new custom fixes to build the arc:TUS110/20TUS115/20TUS120/20Make the first three have 210/8000 restrictions, then make the thrid one have a 180/8000 restriction, since we're getting close to the turn on to the final approach course.Next up is ILLEN, the final approach fix and the first fix on the actual radial we'll be taking into the airport - the TUS 303.TUS303/20 - 180/8000The next fix is VAINETUS303/13.5Notice on the chart's profile view (bottom right of the chart) that you're now cleared to decend to 7300 between 20 and 13.5 DME, so place a restriction of maybe 170/7300 at this fix.Next is NAIRBTUS303/9.5Enter a 150/6100 restrictionNext COPEYTUS303/5Enter a VREF/4800 restriction (get the VREF speed from the FMC Approach page)Next GAVETTUS303/2Restriction VREF/3600If you reach GAVET and you can't see the runway (you're 1000ft AGL and 2 miles out) you'll have to execute a missed approach and try again or fly a different approach with lower minimums.Hope that helps you!Ryan