It's prevalent all over the aerospace industry. It's also why the Columbia was lost (foam shedding happens but it's "in family" ie - it's a known issue that has

It's prevalent all over the aerospace industry. It's also why the Columbia was lost (foam shedding happens but it's "in family" ie - it's a known issue that hasn't prevented a flight from being successful). Complicated systems are always having some issues that aren't to spec. The difficulty is assigning an appropriate risk to them. I've heard people who design 5+ sigma aircraft who refuse to fly on it because they know of some system that isn't up to spec in their eyes; in that case, the opposite is true: they're assigning a risk that is probably too large given the data.