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Old 15th Jun 2009, 06:01
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Graybeard
 
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Mad(flt)Scientist: "If the FMGEC (or whatever its called?) is spitting out an ADR DISAGREE, is that going to then cause either the ADR parts to consider themselves potentially invalid, or other systems to do so? (The FMGEC in effect is "policing" the ADR data in that model)"

The sensors police themselves, but do not police each other. It's up to the data user to compare inputs and apply logic. If there is an airspeed miscompare among the 3 Air Data units for example, the user that receives and compares them will report the outlier to the Centralized Management Sytem, which relays ADR 2 Fault to the ACARS. The user will continue to use and compare other ADR outputs that are valid.

This is why the TCAS Fault stands alone in the reports at 02:10. It does not directly relate to the other faults that could be traced to iced pitot tubes. It may indicate intermittent cabling shaken by turbulence, a lightning strike to an antenna, or a myriad other possibilities, so it may point to the initial aircraft failure - or not.

GB
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