48 Hour Soutwest Airlines Fair Sale

Calling it "one of the biggest fare sales in the company's history," Southwest launched an unusual airfare sale for fall travel.

The Dallas-based airline's sale is based on travel miles, offering customers one-way prices of $30, $60 and $90 depending on how far the flight goes. For flights up to 400 miles, the price is $30; between 400 and 750 miles, the cost is $60; and for more than 750 miles, the ticket is $90.

Customers must travel between Sept. 9 and Nov. 18 and weekend dates are blacked out. The sale also only lasts for the next two days.

Farecompare.com chief executive Rick Seaney said he expects major carriers to match Southwest's fare sale, even if it is for this short period of time.

"The meaning of this sale: it is one indication that airlines are by no means out of the woods yet - as oil prices remain volatile and demand precarious," Seaney said in his morning e-mail.