Thorough crash investigations around the world have led to design and mechanical improvements throughout the history of aviation. The last two decades, in particular, have seen remarkable developments in airplane safety features and procedures. This is because investigations have become more adept at diagnosing problems, while at the same time aviation technology has improved. Even so, annual accident rates have remained virtually unchanged since 1980. Perhaps more disturbing, while accident rates have remained unchanged, the number of flights has grown vastly over the last two decades, meaning that more and more people are involved in airplane crashes.

No doubt many features have saved lives, but there is plenty left to do. And though certain problems are easily diagnosed, changing behaviors and policies in the highly competitive airline industry is a particular challenge. Government regulators, air traffic controllers, and safety inspectors often...