FMC question
 

Can someone explain why on the Airbus A320 models there are only 2 FMC's. I swear A330s have 3 FMCs? Any one explain expand.

Thanx

No idea about the A320 but the A330 has 2 FMGEC's.

The A330/340 family only have 2 FMGECs but there are 3 MCDUs in the centre pedestal.

And some of them (A320's) have a MCDU downstairs as well. Four options.

2 x FMGS with 2 x MCDU on the 320, On the 330 the third MCDU on the centre pedestal at the rear is mainly used by maintance staff for various tasks. Although all 3 MCDU's can print off to the printer the 3rd MCDU is always used by engineers to print off required details for whatever reason.