View Full Version : A320 CRZ FL ABOVE MAX FL fms message....
Nick 1
25th Sep 2011, 07:34
Does anyone know more about this ?
In cruise ex. FL340 FMS start with this message "FMS 1/FMS 2 SPD TGT DIFF"
with flight plan stored or manully loaded , no difference.
After a period of time "CRZ FL ABOVE MAX FL"
FMS reverts from Max Rec Alt es.365 to Fl325 .
Varius test fron Aid Data Computer or Probes report no item.
Thank you.
"Fms1/2 spd tgt diff"
This particular case is mentioned in the new fcoms in flight crew bulletins
It happens when changing the Crz FL using the altitude knob.
The new fcu altitude is sent by the master fmgc to the slave, therefore the predictions are not computed at the same time on both fmgc's, a speed difference may occur during a very short period, triggering the message.
Solution: diregard the message.
capt. solipsist
25th Sep 2011, 11:23
try applying the supplementary procedure for FMGS ERRONEOUS PREDICTIONS :ok:
Eric Janson
25th Sep 2011, 11:29
Just over-write the cost index on the climb/cruise page.
capt. solipsist
25th Sep 2011, 11:34
Correct, that is one of the techniques (although note that in descent or approach, a CI change does not restart a computation). Another is do a Copy Active, then activate Secondary. Yet another is do a DIR TO to the "TO" Waypoint.
FlexibleResponse
25th Sep 2011, 12:50
"CRZ FL ABOVE MAX FL"
This message is generated by one of or both of the following:
1. Pilot inserted or FM calculated Temperature at the CRZ FL is too high; or
2. FM calculated AUW at the point in the flight plan when climb to new FL, is too high.
Normally to fix, enter the correct forecast or reported temperature at the planned CRZ FL.