Hello everyone,I just got the PMDG recently and am a real noob with this equipment..I have mangeged to program a simple plan into the FMC.. Vancouver, BC (CYVR) to Seattle (KSEA)Everything looks good and I take off properly and engage AP A, LNAV and VNAV at about 1000 feet and the aircraft climbs to my cruise altitude (1200 ft) and follows course.the confusion comes when ATC contacts me and tells me to descend, to a certain altitude which I do. I'm not sure how the ATC instructions fall in with my FMC flight plan..I mean, if I descend, my FMC flight plan seems to be terminated..Well not terminated, it's still there on the Nav display, but I can't use Lnav or Vnav.I'm sure I've probably forgot something but would appreciate any help..

If you want to descend dial the altitude into the MCP and press Level Change or V/S, either of which will disengage VNAV. If you are losing both VNAV and LNAV it sounds as though you are also changing the roll mode, for example to heading.

Concur. Remember the FMC does all the work when in a programmed (i.e., the flight plan) mode. When you are descending under ATC control, you are better off coming out of VNAV and LNAV controls in the autopilot and using the Heading, Altutude and Airspeed on the panel. You are going to be vectored to the places ATC needs you to be, not the FMC.

Michael,I think that the issue, simply put, is that although one can pre-program (before takeoff) the FMC to fly the entire flight, that would not normally be done. Yes, the FMC can do that, and there are examples of that in the manual. However, both in simulator and real life, there are usually too many variables to program the entire route, such as weather and ATC. That means a little more familiarity with the FMC to be able to program enroute, or to make modifications to an existing route. Or, as the guys above said, at some point go off of the FMC. It still provides a good situational awareness display on the nav display.The FMC is has remarkable capabilities, but that doesn't mean all of us use all of the features. For myself, I have never been able to use the descent path programming on the FMC because ATC gets me first, and I prefer to use ATC. Hope this helps,keith

Where is the B737 manual at? I downloaded this plane last night and I can't find the manual.

Please sign your name to your posts.I bought the boxed edition which came with printed manuals. How great is that!Under your FS9 folder, you should have a PMDG folder which contains manuals and checklists.keith

Thanks a lot Geoff, DT, and Keith..Your explanation was a big help Keith and sorted things out a bit for me. It will all come together with more practice..ps. FL050 - look at START/ALL PROGRAMS/PMDG SIMULATIONS. Everything is there.