Simplicity vs complexity
The simplicity vs complexity argument was already an old discussion before Pprune but for younger readers someone has to answer the claim that simpler is always more reliable.
This comes from the mathematical "law" that if something breaks every ten years and you have ten of them then you will get *on average* one failure per year. But this is only applicable to stuff that is independent. When the complexity is part of a system then adding more functions can add reliability.
A simple example is multi engine A/C. If I add a second engine to my airplane maybe I double the chances of one engine failing but I improve dramatically the chances of being able to finish the flight with at least one engine. Having two engines doesn't mean I end up in the sea twice as often.
You can also see it from common experience. Old, simple cars used to be supplied with tool kits and breakdowns were common. Modern cars packed with electronics and extra systems yet they fail much less often.
Adding complexity often adds benefits that outweigh any parts count calculations. And be honest with yourself, does the complicated 777 really have a safety record worse than say the DC3?
Last edited by deltayankee; 9th Mar 2008 at 17:54.
Reason: typo!