7 Safest U.S. Airlines, But Who's Counting?

April 11, 2011 -- It's easy enough to name the nation's seven safest airlines. It's hard, however, to say what good these lists are if your goal, as a traveler, is to avoid dying.

Consider the case of the passengers on the Southwest flight earlier this month who heard a loud bang and looked up to see daylight coming through the ceiling of their Boeing 737.

If, before belting-in, they had consulted the latest safety rankings, they'd have seen that Southwest's record is exemplary. On an incidents-per-flight basis, Southwest ranks as the safest of the major U.S. carriers and second-safest overall, coming in just behind much smaller, top-ranked AirTran Airways. (Southwest is in the process of acquiring AirTran.)

Knowing Southwest's safety ranking would have availed the passengers on the pop-top flight absolutely zip. That doesn't mean there aren't steps you can take to help ensure your safety in the air—and we'll get to those—only that studying rankings isn't one of them.

"These lists," says Bill Voss, head of the Flight Safety Foundation in Arlington, Virginia, "are effectively meaningless." Why? Death is whimsical. The reaper can reach you randomly. More importantly, says Voss, "the safety record in the U.S. is so good that it's very difficult to find enough accidents or incidents to draw much of a conclusion about who's safest. There aren't enough data points to draw distinctions between the very safe and the extremely safe."

The most popular rankings compare a carrier's number of flights against its number of safety "incidents." As determined by the FAA and NTSB, "incidents" are events that do not meet the aircraft damage or personal injury thresholds of more serious "accidents." For example, a midair collision between a plane and a bird would likely qualify as an incident. A collision in the air between a plane and another plane would be an accident.

For leading U.S. carriers, there are a whole lot of flights, few incidents and even fewer accidents. So, while it's possible to say mathematically that Southwest outranks US Airways, the difference between Southwest's 0.0000203 and US Airways' 0.0000212 is…small. Too small to have real-world significance, it's a splitting of hairs so tiny as to require nano-tweezers.