originally posted by CONF iture
Would it be possible that when you did initiate your descent, the distance to DEST was more than 200 NM ?
In such case, the system would not activate the descent phase.
As now your distance was within 200 NM when you noticed the CRZ phase was still active, the procedure would be to enter your passing CRZ FL on the PROG page, and the descent phase should activate.
IMO it is not a question of AP/FD ON/OFF.
We tried that, we changed the flight level in the PROG page, to no avail.
I really think that AP and/or FD ON, are the only way to make the FMS do its "duty".
B_D