Pmdg FMC question

[limjack]

How do I get the aircraft to follow the FMC altitude settings in the flight plan? It does follow the speeds as well as the flight plan but just seems to stay at whatever altitude I type in the auto pilot box on the panel. Hope someone knows the answer here so I don't have to sign up at the Pmdg website and add yet another sign in/password to my collection of passwords...lol.

Thanks
Jim

[Boomer]

I dont have the 747 but on the MD11 the pilot must watch his FMC & manually change the altitude. When you hit cruising alt just change the alt to the next setting (even if its hundreds of miles away) & when you get to your descent point she will start to descend.

AFAIK this is a safety measure.

[IanP]

It depends how you are getting there... If you are using Vertical Speed, then the version implemented in the (pretty abysmal) default airliner autopilot is plain wrong and you shouldn't be using it. In a more realistic sim such as the PMDG B744, the two vertical path modes that will get the aircraft to move to and stop at a pre-set altitude are FLCH (Flight Level CHange) which is usually over by the speed controller, which causes the aircraft to climb or descend at the speed you set in the window or VNAV (Vertical NAVigation), which will cause the aircraft to change altitude depending on the settings in the FMS.

If you are flying manually, not following a flightplan, then FLCH is the way to go. If you have fully filled in a flight plan with cruise altitudes, speed restrictions et cetera, then the fully managed VNAV is the best option - although most real world flights will simply be "take off, press LNAV, press VNAV, turn on autopilot, sit back and monitor" in theory. It doesn't always work that way due to ATC vectors, weather, traffic and suchlike.

Edit: It's also worth remembering that you do have to change the altitude set on the glareshield panel for step climbs and any form of descent. You might, I'm not 100% sure, have to press the altitude setting knob on the B747-400 to tell the system to accept your change of altitude. But I might be getting confused with Airbus there!

[limjack]

OK, thats what I thought. When the 747 steps up to my next level I must change altitude to next level and yes IanP, i found out through trial and error you do need to push the altitude button to accept the change.

Thanks

Jim

[Kiwikat]

And also remember that just because you have full VNAV capabilities, sometimes in real life on descent they are actually using VS control along with LNAV. This gives them more control over the descent because they control the descent rate instead of the FMC.

The Super 80 Pro forces you to learn this style of flying because it doesn't even have VNAV descent. So it is a great learning tool if you want to try it. It is certainly more difficult than letting it use autoflight the whole flight and on landing. :kilroy: