ADIRU 1+2+3 faults
Many, many years ago an A340 (I believe AF) entered the very top of an undetected CB and experienced ice crystals of a perfect size to block all pitot tubes and so "faulted" all ADIRUS simultaneously. This immediately "tripped" the a/c into ALTN Law (or would it have even been Direct Law?-long time back).
It was night time and in the cruise with Captain as PF. As he struggled to control the a/c in the turbulence with degraded flt. laws, the PNF (F/O) became very concerned at the various attitudes on PFD and with the tables down, he believed the Capt was not trying to correct the flight path and became directly involved leading to dual inputs which prevailed for some time.
It was this incident, amongst others, which directly led to the modification for "Dual Input" warnings. The source of this information was a magazine published by Airbus for a number of years called "Hangar Flying". I think it was discontinued but not sure. But I could pinpoint the year more accurately with a little research but don't imagine that's necessary here.
I mention all of this to remind that a single external source could affect all ADIRUs and also of course because it occurred in quite similar circumstancesto this latest incident. Incidentally, the only radar return at the time of the first incident was a very small speck of green.
Like one or two others, I am also rather concerned at the some of the statements issued by the French Authorities. Whilst they are quite correct to play down the chances of finding the recorders, I would still expect positive statements along the lines of "whilst recovery may prove imposible, rest assured we will do absolutely everything within our power to find and salvage them"