Page 1 of 1
Yet another PMDG 737 thread......

Posted:
Sat Oct 02, 2004 6:34 pm
by zcottovision
Is it possible to use VNAV descent with the default FS ATC? At the minute I'm using LVL CHG, which sometimes isn't the best.....
Re: Yet another PMDG 737 thread......

Posted:
Sat Oct 02, 2004 7:13 pm
by Nexus
The PMDG FMC and FS ATC are 2 different things and they can't seamlessly
Re: Yet another PMDG 737 thread......

Posted:
Sat Oct 02, 2004 10:35 pm
by Silver1SWA
The FMC can be programmed to begin VNAV descent whenever you wish. If ATC asks you to descend before the FMC is ready to begin descent, force VNAV to begin descent.
Re: Yet another PMDG 737 thread......

Posted:
Sat Oct 02, 2004 11:16 pm
by Nexus
[quote]The FMC can be programmed to begin VNAV descent whenever you wish.
Re: Yet another PMDG 737 thread......

Posted:
Sun Oct 03, 2004 6:06 am
by zcottovision
That's pretty much what I was looking for. Now I just have to figure out how to do it!
Also, why the switch to VS below 10,000?
Re: Yet another PMDG 737 thread......

Posted:
Sun Oct 03, 2004 6:55 am
by Nexus
LVL CHG is so sensitive to speed changes, if you want to lose 10kts, the AFDS will instantly command an agressive nose-up attitude, which sometimes will put you un-necessary high on the vertical path.
If you're noticing that the speed won't drop in V/S mode , simply decrease the V/S and the speed will bleed of..much smoother way of operation, and definetly more comfortable for you and the virtual passengers ;D
Re: Yet another PMDG 737 thread......

Posted:
Sun Oct 03, 2004 8:26 am
by jrpilot
I find it so diff. to make a descent with the PMDG 737 becasue I always come in to high...then the VANZ discounects becasue it can't reach the altitude constraints I've asked it to complete
Re: Yet another PMDG 737 thread......

Posted:
Sun Oct 03, 2004 12:30 pm
by Nexus
Junior do the mental math first, are you constraints on the "right" side of the performance envelope, the aircraft must be able to comply with the hard contraints, you know, or else VNAV will disconnect.
Hint: losing altitude and speed at the same time is never easy in the 737.
Re: Yet another PMDG 737 thread......

Posted:
Sun Oct 03, 2004 2:14 pm
by jrpilot
When I descend 90% of the time VNAV will disconnect and I will have to do a 4000 fpm descent. right away...so what are you saying for me to do...descend earlier?...If I use "descend now" The aircraft only descend at a rate of 1,000 feet per minute...should I use V/S when I use "descend now"...?
Re: Yet another PMDG 737 thread......

Posted:
Sun Oct 03, 2004 4:23 pm
by Nexus
jr, read the post above regarding "DES NOW"

Yes, it will descent with a rate of 1000ft/min, but just UNTIL you reach the original descent path, then VNAV path will follow the vertical profile, as calculated.