Twice now on climbout in the'900 VNAV cicks off way before I reach assigned ALT. then the N1% drops to idle and airseep sinks to a stall. I've recouverd manualy, then Engage VNAV again but the disconnect returns. I also noticed that the traget speed remains at 240kts above 10,000 but the FMC is calling for 319kts. I'n not overloaded and I'm sure the FMC is set right and I haven't passed any restrictions.Ideas?Dave FisherCYYZP4 2.8 GB 478P 533 MHZ CPUP4P800S Asus Motherboard512 DDRGeforce Ti 4200/128Maxtor 80 Gig ATA 133 HDhttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

Dave-Sounds like you might have a conflict with speed intervention running around there....I've just completed a couple of flights with the airplane using VNAV for full climb and descent- and haven't run into what you are describing.... I'll have anthony check in on your post and see if he has any ideas what you might be doing that creates the situation- or whether or not it is something running amock...RSR

Robert,I've just tried the SID with the '800 and it climbed perfectly.I'll ry the '900 tommorrow and let you know if that condition continues.Dave FisherCYYZP4 2.8 GB 478P 533 MHZ CPUP4P800S Asus Motherboard512 DDRGeforce Ti 4200/128Maxtor 80 Gig ATA 133 HDhttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

Dave,The VNAV DISCONNECT message is issued in the following situations (note that it might be a consequence of something not directly VNAV related)- N1 dissymetry of 5% or more- Invalid TOC TOD computations (not the case if you still see the markers on the ND or predictions on the legs / progress page). Can happend if cruize alt is too high relative to FP total distance.- Off the top of my head some configuration where a wpt has a speed constraint not associated with an alt constraint.Let us know how things go...anthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.com