Quick question about VNAV. I have been reading the Continental B737 manual posted elsewhere in this forum, and note that some non-precision approaches have a descent gradient coded in them. An example of this, I believe, would be KSAN RW 27. Does the PMDG 737NG have this capability using VNAV? Are the STARs so coded?Ennis

>Quick question about VNAV. I have been reading the>Continental B737 manual posted elsewhere in this forum, and>note that some non-precision approaches have a descent>gradient coded in them. An example of this, I believe, would>be KSAN RW 27. Does the PMDG 737NG have this capability using>VNAV? Are the STARs so coded?>>EnnisMy guess is that the approach procedures in the current SID/STARS file don't have the altitudes coded, but it wouldn't be too hard to do.I'll pick an RNAV approach at BWI or another non precision approach that has provisions for LNAV/VNAV on the approach chart and code in the waypoints and hard altitudes and speeds. Then I'll fly it in LNAV/VNAV and let you know how it goes.

Great, thanks... Look forward to hearing how it goes! KSAN being one of my favorite approaches (and often quite foggy!), I'm hoping the capability's there.

>Great, thanks... Look forward to hearing how it goes! KSAN>being one of my favorite approaches (and often quite foggy!),>I'm hoping the capability's there.Short answer is YES, you can fly a non-precision approach in LNAV/VNAV very well.You can do this two ways (in the sim).You can edit the SID/STARS file for your airport and put in the waypoint altitudes in the approach section, just as I did in the example below for the KBWI RNAV Y 15R approach:APPROACH RNAVNP15RY FIX BLABR 2500 SPEED 180 FIX KEVVN 2000 RNW 15R FIX RANGL FIX SAYLR 2500 HOLD AT FIX DATED RIGHT TURN INBOUNDCOURSE 187 ALT 2500 SPEED 230 LEGDIST 4 TRANSITION EMI FIX EMI 4000 SPEED 180 FIX BMORE 4000 SPEED 180(The numbers right after the FIX NAME is the altitude constraint).or you can insert the altitude constraints in the FMC LEGS pages. Since the vertical path is always a straight line (constant angle) from the FAF (KEVNN in the example above) to the runway, as long as those altitude of those two points are defined the autoflight system will try to fly that path in VNAV.The trick in VNAV to manage your speed (until we get SPD INTV in the 800/900) is to use your flaps. Extending flaps will force the FMC to set a new speed target. When I test flew the approach above, I had the gear and flaps 5 set crossing BMORE, and then extended flaps 15 at BLABR, and out to 30 as I approached KEVNN. The autopilot flew the approach vertical profile PERFECTLY, and I disengaged the autopilot at minimums and landed normally.In the real-life airplane, the altitude constraints will be already in the database, and you will NOT be able to modify them.