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.

Rankings Show Airline Safety Record

AirTran, Incidents per flight: 0.0000196

Southwest, Incidents per flight: 0.0000203

US Airways, Incidents per flight: 0.0000212

Continental, Incidents per flight: 0.0000260

Delta, Incidents per flight: 0.0000386

United Airlines, Incidents per flight: 0.0000407

American Airlines, Incidents per flight: 0.0000701

--Source: FAA and NTSB

You'd think that Christopher White, spokesperson for AirTran, would like to do a little boasting about his carrier's safety supremacy, but he, too, emphasizes that the top carriers are interchangeable when it comes to safety. "Everyone is 'safest,'" says White. "Today's aviation system in America is the best in the world. At AirTran, we do have a couple of things going for us: We have an extremely young fleet, the youngest all-Boeing fleet in the U.S. Newer planes give you less to worry about, fewer mechanical issues." AirTran also has scored highly for overall customer satisfaction.

So, what can you the traveler do to help ensure your safety? Quite a lot, say experts. Advises Voss, "Look for airlines that have passed what's called an IOSA Audit, which goes above and beyond most regulatory requirements for safety." The International Air Transport Association (IATA) maintains a registry of airlines that have passed this audit. "Second, look to see if your carrier is part of a larger, global alliance, because airlines are very discerning about who can join these." As examples he cites the STAR and OneWorld alliances. Third, if flying internationally, see if your carrier has been placed on the so-called 'European Commission Blacklist'--which is pretty much what it sounds like: a list of airlines banned for safety reasons from operating within the E.U.

Airline industry analyst and consultant Robert W. Mann of Port Washington, New York, says the best thing the traveler can do is to be "situationally aware"—in other words, keep your eyes and ears open, and if you see something that disturbs you, act on it.

He cites a flight he boarded some years ago on which "it was just clear that the plane hadn't been maintained properly. There were exposed wires and exposed insulation. I just didn't feel comfortable, so I got off." He was traveling on somebody else's dime at the time, but, he says, "If it had been my own money, I'd have done the same thing."

Furthermore, if you do see something that strikes you as wrong, call it to the attention of the crew. The worst that can happen, he says, is that you'll mention your concern to the flight attendant, who'll pass it up to the captain, who'll send word back, "Thank you, but it's not a safety issue."

Mann, who is accustomed to flying in bad weather, doesn't hesitate in winter to ask crews if they're sure a plane has been properly de-iced. He says he knows of incidents where passengers, concerned about there being too much ice or snow on the wing, have rung their call button, told their concern to the attendant, and the result has been that the captain, in agreement, has turned the plane around for a repeat de-icing.