Jump to content

Sign in to follow this  
Guest jkendrix

PSS 777 FMC (CDU) VNAV DES Hangs FS2004

Recommended Posts

Guest jkendrix

Hi,I've noticed that when using the FMC on the PSS 777 that it has a tendency to come in hot. I've tried starting the descent earlier by entering a crossing restriction on a waypoint. I also enter some speed restrictions. That crossing restriction appears to work fine but the speed isn't adjusted appropriately. For instance, if I enter .73/20000 for a waypoint. The speed just seems to keep increasing. I expect when passing through 10000 that the speed will drop to 240kts (the default restriction). Instead, it seems to want to stay at .73. If I try inputing too many waypoints or making too many changes then FS2004 will just hang. Until this is fixed I'm going to have to put this plane back in the hangar. I'm hoping that this will be addressed soon!!Thanks,John

Share this post


Link to post
Guest dt1951

I never use VNAV for descents. I dial in a mach number about FL300, and 290 knots below until I reach a speed restriction point (like a crossing point on a STAR), at which time I dial in taht speed. In all the forums I have read, real world pilots say that VNAV descents aren't used.

Share this post


Link to post
Guest jkendrix

Really?! It seems amazing that LevelD and PMDG would model something so expertly that is never used by Pilots in the real world. I'm sorry, but I have to disagree. VNAV descent is valid, and it should be properly modeled. In fact, if you look at the manual for the FMC that PSS puts out you will see that VNAV descent should work, but right now it's not. I can try using your method until PSS gets the FMC fixed. I'm used to being able to modify the flight by entering restrictions in the FMC in LevelD767 and PMDG738 so it's frustrating to have it hang FS2004 with PSS777.

Share this post


Link to post
Guest jkendrix

Try making multiple modifications to the descent profile. It hangs FS2004. I've seen other reports of this hanging as well in the forum. PLease fix this! Don't blow it off!John Kendrix

Share this post


Link to post

Works OK for me too.I select an appropriate STAR, check the FMC for the minimum safe altitude as I'm going, dial it in, select FL CH and reselect VNAV and it's fine. Follows the guage faithfully. Does tend not to follow the STAR very well though. Has a habit of missing out waypoints to take a shorter route resulting in very steep (4k fp/m) descents to catch the line, but once it's caught the line again it's fine, although some shortcuts means it misses the ILS i/p point and needs to circle back around to get it right (that is wrong). I suspect a problem with the STAR as the curve seems backward (it doesn't mtach the genuine Jeppessen real world charts I use), but that's not a PSS problem.I just hang a bit of spoiler out to keep the speed down.Recently flew to Mexico on a real BA T7 and they used about 25% spoiler all the way down from FL300 to about 8,000ft as the descent was more than 3k fpm. 1st Officer told me that this was completely normal. Another flight in a BA 737 into EGKK was done without VNAV on the way down too. Again the stepped descents under ATC instruction were of the 3k fpm type. The Captain told me they can't use VNAV very often as ATC determine their FL not the FMC/FMGC computer.Richard

Share this post


Link to post
Guest jkendrix

>vnav des with no modifications work fine>vnav des with fp mods causes probs, it is on the list>>John>PSS SUPPORT>support@phoenix-simulation.co.ukGood! I look forward to a fix!!! It's a really beautiful plane and I love flying it.John

Share this post


Link to post
Sign in to follow this  
×
×
  • Create New...