If Southwest gobbles AirTran, do travelers get indigestion?

Travelers are entitled to some mixed feelings over the pending deal disclosed Monday of Southwest Airlines swallowing AirTran Airways.

On one hand, Southwest has always aimed for low prices, cheerful service and simple operations (flying only 737s, for instance, and not assigning seats). In doing so, the company has grown from a Texas start-up in 1971 to, as of today, a behemoth with more than 650 aircraft serving almost 100 cities.

So maybe we should be cheering that, if government regulators give their blessing, Southwest (strongest in Las Vegas, Chicago and Phoenix) will have its way with all those AirTran flights serving Atlanta, Orlando, Baltimore, New York, Boston and the Caribbean, among others.

So why are some consumer advocates wringing their hands over the likely disappearance of the AirTran brand? Because no matter how warm and fuzzy Southwest may seem, less competition usually means high prices for consumers.

Who, for instance, thinks air passengers are better off since US Airways and America West merged in September 2007, or since Delta and Northwest completed their merger in January, or since United and Continental announced merger plans in May? Anybody?

In the big picture, the Southwest-AirTran move is bad news for low fares, says George Hobica, an airfare expert and founder of Airfarewatchdog.com, because “it may cause other airlines to consolidate further. And that’s where it gets dicey,” Hobica said. “It may just create an avalanche of further consolidation.”

In terms of immediate effects, “people should be thrilled in Atlanta,” Hobica said. With its substantial presence there, Hobica said, “AirTran was a small thorn in the side of Delta’s fuselage. Southwest is going to be a much bigger thorn.”

Meanwhile, between Baltimore and Boston, Hobica expects consumers to pay a bit more. AirTran, Southwest and JetBlue have been at war over that route for more than a year, he said, with fares frequently down around $39 each way. With AirTran out of the picture, Hobica predicts, “you’ll see $59 and $69 fares” on that route. “It gives everyone permission to raise fares.”

AirTran, born amid a flurry of airline mergers in the early 1990s, has been using two kinds of jets, offering assigned seats, has a business class and has been reaping significant fees for changing tickets, all features alien to Southwest’s corporate culture.

Though much remains to be explained, Southwest officials have said they will eliminate the baggage fees charged by AirTran, one clear win for consumers, right off the bat.

Here, as the AirTran brand vanishes and Southwest grows, are a few other things for root for. (The numbers below, unless otherwise attributed, come from the U.S. Department of Transportation’s Bureau of Transportation Statistics and Air Travel Consumer Report.)

On the subject of bumping—when airlines deny boarding to passengers, usually because of overbooking— let’s hope the AirTran folk can give Southwest a little schooling. In the first half of 2010, AirTran’s denied-boarding rate was 0.5 per 100,000 passengers, well below the major-airline average of 1.37 per 100,000. Southwest Airlines, meanwhile, ranked 12th among 18, with 1.75 passengers bumped per 100,000. (The story was similar in the first half of 2009, when AirTran’s rate was 0.33 and Southwest’s was 1.37.)

Let’s hope Southwest, a perennial industry leader in on-time performance, can get AirTran on its schedule. For the year that ended in July, AirTran ranked 11th among major carriers in on-time arrivals, with 78.4% of its flights coming in on time. Southwest ranked fifth, with 81.3% of flights on time.

In the area of baggage fees, which have been rapidly rising throughout the industry, penny-pinchers will be grateful for Southwest’s extension of its no-baggage-fee strategy. From April through June, AirTran collected $39.2 million in baggage fees, the sixth-highest amount among major carriers. And in September, its fees rose to $20 for your first checked bag and $25 for your second.

Then again, if you believe in paying more for better performance, you just might like AirTran’s baggage style better than Southwest’s. In July, AirTran mishandled just 1.75 pieces of baggage per 1,000 passengers, an impressive rate that was surpassed only by Hawaiian Airlines (1.69 per 1,000 passengers). Southwest ranked down in the middle of the pack, ninth among 18 major carriers, with 3.72 mishandled-baggage reports per 1,000 passengers.

As for overall consumer complaints to the federal Department of Transportation, both airlines look strong, but Southwest is stronger. In July, complaints about Southwest amounted to 0.23 per 100,000 emplanements. That ranked Southwest tops in the industry. AirTran was fourth, with 0.62 complaints per 100,000 emplanements. The average complaint rate among the 18 major carriers was 1.3 per 100,000 emplanements.