A320 WX RAD question
 

With failure of the FCU, the weather radar is inoperative, can anyone tell me why this is?

Many thanks

What kind of failure do you mean?
Basically:
If the radar did not get a signal of range selection, he can not give you the correct data. ;)

Makes sense IFix, thank you. Don't know the exact nature of the failure, I are pilot, magical things hidden from me, info provided only on need-to-know basis according to instructors.

The ND defaults to 80nm range, why did the Airbus folks not have the WX RAD also default to that value?

Hi Bingo! i think the chances of the dual FCU failure in flight plus flying in IFR conditions as well as in the middle of the atlantic ocean somewhere is close to nil.If it really does happen, i think u will be diverting back to the airport where the weather is good or perhaps ask ATC for radar vectors outta weather.