Help in Top of Descent

[Lonepilot 9]

Hi!This is from page 24 in the 777 FMC manual.http://simvideos2.com.sapo.pt/TOD1.JPGYesterday I was flying at FL390 from LOWW to LPPT. The approach was set and as I was approaching the T/D symbol I reset the MCP altitude to 6000. I passed T/D but the plane did not start an automatic descent, just remained at 390. So I had to push the altitude button and then she begun the descent. Nedless to say that I had to switch to V/S with a steep descent and apply speedbrakes in order to track again the VNAV path.Would appreciate some help as im pretty sure the plane is not performing well.Best regards,

[baw716 0]

Hi all, I experienced a similar problem. The VNAV captured the speed reduction, but not the altitude reduction. It should have started a descent as soon as the aircraft was slowed down, but it did not...it needed a little help. I disco'd the VNAV, changed to FLCH, initiated the descent and flipped back to VNAV (which I actually didn't think I could do), and it held the descent profile all the way down to the correct point. More detail in my flight report.Thanks to all, Dave Lamb