Regarding that helios crash, and the pilots mis-identifying the horn: I think I could safely say that 99% of all Boeing pilots have heard that horn at some point in their career. And I'd say 90% of them have heard it in association with a configuration problem, while on the ground. Is it a big deal? Nope, not at all, until you're in the air, and the air is getting thinner by the second and then the horn goes off, and your first thought is... 'wtf is the configuration horn going off for?' Now you're getting a little light headed...getting giddy. how many seconds left do you have before you have a chance to remember it's a dual horn?
We are all taught that Hypoxia is insidious, that it's effects are different in different people, yet we have an alarm for a pressurization failure that is also insidious! Sure, an explosive decompression is impossible to mis-diagnose, but in the case of helios, the cabin rate was relatively slow compared to let's say, a window popping out in cruise or something.
I'll admit, I've been surprised in the sim, and it took a good solid 5 seconds or so to realize what the horn really meant, and another second or two wasted before I realized that I could cancel it(you can cancel it in the air, but not on the ground), and that was without the sneaky effects of hypoxia. Bottom line is, Boeing cut a corner by sharing the horn with 2 separate warning systems. Yes, only one can happen on the ground, yes the other only happens in the air, and the logic is perfect for a guy who wears a white coat and has a pocket calculator stuffed in the breast-pocket, and isn't in the plane at high altitude when the climbing cabin altitude is causing an intoxicating effect.
Given enough time, I'm sure the Helios boys might have figured it out, but they ran out of time and air.
The good news is the planes now coming off the factory line are getting additional lights installed to help the pilots identify and recognize a pressurization failure sooner, which will save lives. And, as per the Boeing play book, just like with the rudder hard overs, just like the exploding center fuel tanks, and now, just like the altitude warning horn... deny deny deny, blame the pilots, etc.
I guess you can't blame them; after all, how many lawyers does it take to file a class action lawsuit and sue successfully? Then they quietly fix the design flaw all the while denying the existence of any design fault on their part.
But hey! At least they fix it...

In the end the improvements are made; hell, maybe we can thank the ambulance chasers!

Drinking outside the box.