Good Day Everyone,
Yesterday, we were flying without auto thrust (it was U/S) and it was a new interesting experience for me. But I got a bit confused how does the FMGS works in the case you fly half manually( manual thrust control) and half managed (AP/FD ON).
For example, if you are cruising at FL 330, thrust is manually set to maintained the current managed speed and you select FL 120 and Pull OPEN DES but you intentionally don't move the thrust levers. The plane should not start descend as in OPEN DES the FD will pitch UP or Down in order to keep the speed. Right?.
Please correct me if I'm wrong.
Now we were in managed descent on the profile so the thrust levers were set to IDLE. Captain was PF and I asked him if he could put some power to see what's going to happen. He did spool up the engines and the speed went way through the upper limit of the brackets... I was a bit confused as I thought the FD will command a pitch up to stay within the speed bracket limit..
Could someone help me on this one?
Thank you.
