Troubled Flight

[Guest]

I am NOT by any means comparing products but experienced something strange yesterday. I set up and flew from KORD to CYYZ using a 767 with the real weather thingy in FS9. I used a STAR for the approch to CYYZ and landed perfectly.I then set up the 747 using the same flight plan perameters minus the STAR at CYYZ which was non-existent in the FMC. At takeoff the 747 did a 360 degree turn to magenta line but all went well using vnav until decent. The plane descended according to altitudes set on the FMC legs page but the speed stayed at 300 knots and would not change. I had to use MCP speed control to slow down. I am going to try it again now because I may have missed some small detail but if anyone can think of something obvious from what I have typed so far I would appreciate it.Rick

[lostmoon 0]

did you descend in vnav? if so, make sure that the speed restraints are entered into the fmc.if you descended in FL CH, then, you don't have speed protection. i don't think you get speed protection during V/S as well.

[MELKOR 5]

Assuming that VNAV was in "PATH" mode, the 747 was doing the right thing: i.e. pitch to maintain a path - with no regard to your speed. I, too, have been confused about the behavior of FMC modes - do a little reading on the subject, and you will quickly find that PMDG has done an excellent job of modelling real-world FMC behavior.- Bill

[MELKOR 5]

Actually, no: in FLCH mode, the aircraft pitches to meet a speed. So it DOES have "speed protection", as you say.In V/S mode, the aircraft will maintain whatever rate you have commanded - with no regard to speed.- Bill

[Guest]

you need to download the sidstar package from navdata.at

[MELKOR 5]

BTW, there is a useful summary of Vertical and Lateral modes here:http://human-factors.arc.nasa.gov/IHperson...vers/App-A.html- Bill

[Guest D17S]

For what it's worth, here's my take on Vnav path descent: "Descent: The FMC will alert you to screw down your altitude so the FMC can begin its scheduled descent. Here, you are just getting this altitude setting down out of the FMC

[Guest]

I have done the reading and I have flown many flights with no problems and yes this palne is modelled nicely. LNAV was working and VNAV was working as well. All speeds and altitudes were set in the FMC as they are every time I fly the 747. The speed just didn't change but the plane decended as programmed.I downloaded the latest airac again and loaded it again and this time the speed did change but there were no sids for KORD and no stars for CYYZ. All I got was an NDB for six left.I will try a different flight tonite. Thanks for the help.RegardsRick