Getting from here to there by air can be a frustrating experience. Equipment failures, bad weather, even low clouds can set off a chain reaction of flight delays and cancellations at busy airports. The effects of problems at one airport can readily end up affecting airports across the country and around the world. At times, the international air transport system seems poised on the brink of failure.
Indirectly, the same system also plays a role in the transmission of deadly diseases, such as influenza and, most recently, Severe Acute Respiratory Syndrome (SARS), which passengers can unwittingly carry to new locations before getting ill themselves. Indeed, air travel played an important role in the spread of SARS in March 2003.