Thinking Outside the Box, by Karen I.
My father was an engineer at Boeing, and Boeing builds in (or at least they used to) triple redundancy. Kind of hard to find a hardware store or plane mechanic mid-air over the Atlantic, so you can see why what appears to be over-building really isn’t in the case of an airplane. You might think that to effect this on the ground you’d need three or more of everything, but that’s not actually the case. What you need for food, for example, is obviously more than one year’s supply. You aren’t going to quit eating if you can help it, …