Originally Posted by
krismiler
Surely a synthetic airspeed system would be more than a simple software upgrade ? The sources used to calculate it would need to be tied in to some form of computer with the ability to reject an erroneous input, calculate a value and then display it. This is more likely to require a major upgrade of the system, possibly a hardware change as well.
My educated guess is that they are going to use the flight control computers - which already receive data from several other systems (ADIRU, GPS, etc.) - to calculate a synthetic airspeed when the normal ones either disagree or are judged to be unreliable. So it would be a basic s/w update to the flight control computers.
If they can't do it all in s/w and need some sort of hardware update, all bets are off. But updating the flight control computer s/w is a long established process once the new software is certified.