MCDU question please?

[G7USL 117]

I entered a flight plan into the MCDU last night and all I kept getting was 'UNABLE CRZ FL' error.I checked the flight levels and corrected what I thought was the discrepency as after entering a flight level of 10,000 and reducing to 6000 I noticed that the following flight level was back to 10,000? I re-set it to 6000 but the MCDU kept putting it back thus sausing the error.Can anyone tell me what I was doing wrong? Norman maybe?Dave T. .........On the lovely warm Devon Riviera and active 'FlightSim User's Group' member at http://www.flightsimgrpuk.free-online.co.uk/

[Guest vrandar]

The UNABLE CRZ FL is caused when your Top of Descent is going to be before the Top of Climb in the F-PLAN. So either reduce the cruise FL in the PROG page of the MCDU or you can try reducing your weight.You say your flight level is being re-set: on which page of the MCDU and which LSK line is this happening as I have never known anything other than manual intervention change the FL in the INIT page or the PROG page? Where did you do the reset?What flight are you doing and what is your FL, ZFW and block fuel?

[Guest NormanB]

Dave,Like Rob, I have never seen the behaviour you describe. Catch me omline if you want to describe this real time. It certainly sounds like you are doing something not quite right.