I'm having a weird problem when descending with VNAV. If I let the aircraft reach top of descent and start down on it's own in VNAV, everything works normally and the power reduces to idle smoothly. However, if I use the "descend now" function, it will start down slowly and reduce power a little bit like it's supposed to, and when it catches up with the VNAV profile and captures the path for a steeper descent, the throttle mode switches to "hold" and will overspeed if I don't manually reduce power to idle. Perhaps I've missed something, but I believe it's supposed to retard to idle at this point on it's own. Any input would be greatly appreciated!

I'm having a weird problem when descending with VNAV. If I let the aircraft reach top of descent and start down on it's own in VNAV, everything works normally and the power reduces to idle smoothly. However, if I use the "descend now" function, it will start down slowly and reduce power a little bit like it's supposed to, and when it catches up with the VNAV profile and captures the path for a steeper descent, the throttle mode switches to "hold" and will overspeed if I don't manually reduce power to idle. Perhaps I've missed something, but I believe it's supposed to retard to idle at this point on it's own. Any input would be greatly appreciated!

If your using a hardware throttle, be sure you bring it back to idle as well else you will get this problem. Its in the manual somewhere, I think it was the tutorial. 

http://forum.avsim.net/topic/419791-vnav-descent-oddities/