12 Plane Crashes That Changed Aviation

(via Popular Mechanics)  Flying in a jetliner is extraordinarily safe: There have been no fatal crashes on a U.S. scheduled airline in the past seven years, an astounding record considering that more than 30,000 flights take off every day. How did flying get so reliable? In part, because previous accidents triggered crucial safety improvements. Here are 12 accidents whose influence is felt each time you step on a plane.