Idle engineering note: those airframes were engineered for a 40-year-plus service life, and then over-engineered beyond that, engineers thankfully being the conservative creatures they are. (Well, what's a little I-35 bridge collapse among friends? Or Apollo 1? Or...one begins to see why engineering managers tend not to have peaceful sleep.)
But despite just undermining my point my friends in Boeing -- and even, yes, EADS -- are people I would and do trust with my life.
Civil engineers, close but not quite as much, now that I think. Thank goodness buildings and bridges do not, generally, have to fly.