A few hours?!?!?! This requires the programming of cascading sets of Kalman filters...the first set of calculations has to normalize the pitot/static differences due to the local flow effects of the respective locations. Since the MAX pitot are fixed, and AoA are free to rotate, the effects must be compensate for in the sideslip flow. (MAX does not have sideslip indicators.)
Since the MAX only has 2 ADIRU's, the computing power is already used up.
The second set of Kalman filters will balance the differences, and the third set of filter will provide the synthetic resultant.
Who expects this many levels of filter to provide an accurate resultant, especially given the software issue that BA currently has???
They should have simply added another AOA sensor to the tail, and either hard wired it in...What about replacing the 2 pitots with the combi pitot AoA??? now instead of 2 AoA, they would have 4, and how difficult would that wiring have been???