btw, from what I see, A320 has 2 ELAC (elevator and aileron computers) and 3 SEC (spoiler and elevator computers); the ELACs were produced by Thomson-CSF based on a 68010 CPU and the SECs were made by SFENA/Aerospatiale based on the 80186, as already noted. So you have 2 sets of completely different Hardware (CPU and architecture), and also different functional specs. (and at the Software Level, you have 4 different Software packages: ELAC control channel and monitoring channel, and SEC control channel and monitoring channel). Then there's also the FACs, for the A320...all this info is easily available. Imho this level of redundancy is completely appropriate, it's not "overdone" in any way, it's just based on safe and sound principles to avoid common mode failures, conservatively engineered, and adapted to the capacity of the hardware.
if you look at the A380, a much more modern design, possibly there's been a minimal increase in functional density (I counted 51 control surfaces vs X for A320?), but it still needs 3 Primary Flight Control and Guidance Computers, 3 Secondary Flight Control Computers, and 2 Slats & Flaps Control Computers.
I can't see how reducing the number of computers would be of any big help for anything (quite contrarily).
Last edited by deptrai; 30th Jun 2013 at 18:16.