Taipei, Taiwan THE crash of a Comair jet in Kentucky on Sunday ended the longest safety streak in aviation history: it’s been almost five years since a passenger died in a commercial airline jet accident in the United States. Crashes are actually very crude gauges of the safety of air travel because they remain so rare. We must pay attention instead to the little events that happen every day in the skies and on the ground that very, very slightly increase the risk of another disaster. For instance, a pilot attempts to talk to an air traffic controller but is...