View Full Version : A320 FMGC - Independent Mode

21st Mar 2009, 15:49
Independent Mode is displayed on the scratchpad - Airbus state there is no MEL to apply because the FMGCs are still working. Troubleshooting is problematic and because of an upgrade program on spares, swapping out boxes (even swapping out both) is moreso. To keep the operation running you dispatch in Independant Mode and will continue to do so for quite a few more cycles.

Does anybody have any experience to relate or advice to offer on some of the issues / concerns associated with operating while FMGC's are in Independant mode?

eg FCOM advises crew to manually enter the same data on both MCDUs. How do you handle that below 10,000 when PF is supposed to be flying? PNF has to reach across and make same entries in PF's MCDU and hope he didn't make a typo?

eg Aircraft remains Cat II/III capable but would you impose restrictions?

22nd Mar 2009, 01:31
We do not allow independent ops, but you asked the correct question....turn down the aircraft because one crew member will be heads down below 10000.

22nd Mar 2009, 10:28
PNF has to perform revisions on both MCDUs

22nd Mar 2009, 10:40
Independent mode can be triggered by a database discrepancy, ranging from NAV DB to AMI, or from weight, speed FMS/FG discrepancy, or position.
So the first thing is to know the reason of the independent mode, when the reason is known, the restrictions will be clearer, in anycase remember that you are not in DUAL MODE, so any operation requiring DUAL MODE is a NO NO :=.

23rd Mar 2009, 23:53
Thanks for the feedback folks. With the age of our FMGCs and the lack of spares this issue is becoming real ugly real quick here with little support from Airbus in terms Flt Ops concerns re Safety.

As you all agreed, into busier dest'ns, below 10000, I just don't see how you can operate without relaxing a level of safety.

New or upgraded units are something like a 1/4 mill apiece so you can imagine the reaction to the obvious solution in recessionary times. Still fighting for it though.

Anyway's, thanks again for the feedback. Twas much appreciated.

24th Mar 2009, 05:21

I think your fleet is equipped with a Legacy HWL FMS1, if it s the case I think that you cannot be P-RNAV Approved due to data base size.
PM a message with company name, I will send you contacts within FMS suppliers.
It is not that expensive.