The Air Caraibe report shows that the NAV ADR Disagree is a consequence of clogged/iced Pitot tubes and static ports and slightly different patterns of errors on each ADM generating the disagreement, making air speed and maybe also barometric altitude erroneous/inconsistant (this may be a potential problem for the TCAS ?). The NAV ADR disagree did not require a manual intervention of the pilots on one of the ADIRUs to appear.
All the faulty instruments, the ADIRUs, the ISIS and the TCAS appear to be inputed by Pitots, static ports or barometric pressure sensors. What if these Pitots and the airframe (static ports) were rime iced crossing a cumulonimbus ? If in the mist of a tropical cell, subjected to turbulences, severe icing conditions, a gradual deprivation of all air references (air speed), followed by a cascade of faulted nav instruments, multiple alarms in the cockpit, unreliable/unconsistant indicators, loss of flight assistances/protections, maybe a stall due to erroneous air speed which surprised everyone on board ? (pilots trying to understand/cope with the multiple failures, air crew). A stall followed by a dive, resulting in an overspeed during which the vertical aileron (and the spoilers ?) may well have been ripped off (not protected anymore against excessive manoeuvers in alternate law) before a critical airframe break up.
Hope these black boxes will be recovered soon.
Jeff