Airlines offer deep cuts on ticket prices

— -- A trio of discount airlines led by Southwest on Tuesday rolled out some of the lowest fares seen in years.

The sales are short-term offerings. Southwest's fares must be bought by 11:59 p.m. PT Wednesday, while the sales window for AirTran prices for travel on off-peak days through Nov. 11 remains open through Thursday. The Frontier sale expires on July 14. Travel on those tickets covers a longer period: Aug. 10 through Jan. 15.

"This is the biggest, best fare sale of the year," said veteran airfare watcher Tom Parson, CEO of BestFares.com in Arlington, Texas. He called Southwest's fares "the kind of sale you write Mom about. Heck, it's the kind of sale you fly in Mom for a visit."

The low prices are a throwback to the mid-1990s, when fares that low were designed to entice passengers during a post-Gulf-War travel slump.

"We haven't seen $30 fares in at least 15 years," Parsons said. "I remember in the mid-'90s when people were excited about $99 coast-to-coast fares. These are $90, a decade later."

The sales come after most U.S. airlines pushed through their first fare increases of the year in June, then let most of their big summer sales expire on June 30. Fare watchers weren't expecting to see new sales announced until August, when airlines typically begin drumming up business for the slow fall travel season.

"This tells us that fall travel is real light," said Terry Trippler, another veteran airfare watcher at TerryTrippler.com in Minneapolis.

U.S. carriers have been reducing the number of available seats since last fall as fewer people travel amid the recession. Many plan to cut more by reducing flights or moving to smaller planes in the fall.