Thanks for the quick reply Jan,
It may be the "engaged mode after pressing CMDA" - I was on a SID and the initial altitude is 6000ft, after which the climb to cruising FL is permitted.
I set 6000ft in the altitude window and shortly before the waypoint at which the restriction is lifted I reset to cruising level (FL280). However we flew past the waypoint with no climb abd when i checked, the VNAV button was no illuminated. When I prssed it, then I got stuck in CWS P mode.
However, it may possible be I missed the waypoint and only increased the altitude set after it - whereupon it may have affected the AP mode. But after resetting the altitude window to FL280, I cannot get either VNAV or LVL CH to work.
Could you suggest a testing logic for me? I was on a BCN1X SID out of EGGD.
Thanks,
Roger.