Does anyone have any idea regarding whether things like AOA, Pitot Pressure, Static Pressure, Acceleration and TAT start out as digital information or as analog information that is then processed to digital on A330 systems?
If initially analog data, RC smoothing can smooth spiky ouput very reliably and predictably if the time constant is appropriately chosen. Of course if the data is just plain wrong, the output is just as wrong. Data that starts out digital encounters the problems of choosing appropriate processing techniques that JD-EE has discussed.
Ideally data needs to be reviewed for appropriateness before being used by aircraft systems.
Checks such as:
Is the value reasonable by itself?
If the value is changing, is the rate of change appropriate?
Is the data consistent with other related aircraft data, not just with like sensors, but with related aircraft sensors.
Has there been recent anomalous behavior by that sensor?
Data input identified as suspect should have its confidence rating reduced appropriately so that it is not used or is minimally used.
Data checking would probably require a new computer (in triplicate) together with certification of its correct operation. Trying to use existing aircraft computers for this purpose would likely slow them down.
The present Airbus solution to the airspeed problem seems to be diversity of pitot tube manufacturers. Perhaps they too believe AF447 encountered a synchronous common mode pitot icing situation. They not only removed Thales
P/N C16195AA pitots from service, but instituted a defined mix of Goodrich and Thales pitots.
From
AD No.: 2009-0195
" replacement of Thales Avionics P/N C16195BA pitot probes at positions 1 (Captain) and 3 (Stand by) with Goodrich P/N 0851HL probes and the installation at position 2 (First Officer) of a Thales Avionics pitot probe P/N C16195BA."
Does anyone have data on how this new pitot configuration is faring?