777 FMS descent rate

[Check Airman]

Hi all,

What rate of descent is targeted for an early descent or cruise descent? The FCOM is pretty vague and only says it’s at “reduced descent rate”.

Thanks

[STBYRUD]

The TMCF calculates a thrust setting to achieve approximately 1250 fpm (FCOM 11.42.33 and 11.42.34)

[Check Airman]

Excellent. Thanks!

[Flyboyjake]

Keep in mind, it will set the thrust required for that descent rate at your current altitude, and then release the thrust into "hold". As you descend, the thrust that was set at a higher altitude will soon be too much for 1250fpm. If you let it go long enough without catching path, it will nearly level off, as the thrust required for level flight at fl230 may be what's required for 1250 descent at 410.

Hold gives you the thrust levers, so you'll have to adjust manually on the way down.