I presume this was not the very first time an A330 had (attempted to) land(ed) at Tripoli? Assuming not, if the "computer" did it, how come these other flights managed to land OK. Did the computer just decide that this time it was going to screw up?
I have worked with computers for my entire life and find this whole line of discussion just plain wrong. The code running in the Airbus family is embedded, and quite different from the run of the mill home/office PC code we are so used to locking-up/crashing.
The code we're talking about here is much more akin the engine management system of your car (admittedly many times more complex) but (this important) the code is running as a single thread, dedicated to the computing platform itself, NOT parasitically balancing on top of a general purpose operating system like Windows or similar, that is designed for you to run Word, iTunes, your email, and any number of other applications all at once, and allow you, the user to switch them in and out at random.
An FMC runs FMC code. That's it. So the problem of testing it, debugging it, and error handling are in fact much simplified. Also the code itself is subject to REAL testing, unlike the majority of domestic/office code that is in the main left to trial by fire testing with beta testers...
Also, as another contributor has already pointed out, these systems are multi-redundant, and have at least 2 suppliers that developed code entirely independently.
I'm not saying these systems are infallible - but the problem is the USER. Despite all the protections built into these systems, if the pilot commands the aircraft descend, then descend it will.
Much more likely in this case is that the crew thought they were somewhere different than they really were and, due to a combination of sun, haze, and perhaps fatigue (other posters have already crafted similar and better written scenarios for this), got the aircraft into a position that was unrecoverable, no matter what automation was available to them.
- GY
