After the airline went through bankruptcy twice, turnaround expert George Putnam now sees improving long-term prospects for US Airways (NYSE: LCC).

In his The Turnaround Letter, the advisor suggests, "When travel does begin to pick up again, US Air with its lean cost structure should profit handsomely." Here's his review.

"US Airways began in 1939 as All-American Airways delivering mail to Western Pennsylvania and the Ohio Valley; from there it grew through acquisitions to be a major national airline.

"If there's one sector that stands to benefit handsomely from a further slide in oil or, at least, a moderation in crude's rally: the airlines," explains energy sector expert Elliott Gue.

In The Energy Strategist, he says, "Airlines may make a terrible long-term investment but can be an outstanding short-term trade." Here he looks at Delta Air Lines (NYSE: DAL) and, for the even more speculatively-inclined, US Airways (NYSE: LCC).

"Some investors will rightfully cringe from any mention of this sector; after all, the airlines have consistently lost money throughout their post-deregulation history.

"Most of the majors have declared bankruptcy on multiple occasions since that time. However, we've traded the airlines on a few occasions; we took some triple-digit percentage gains in the airlines back in 2005.

"The airlines' leverage to oil prices is well known. Expectations are so low, in fact, that several major air carriers actually managed to beat consensus expectations in the second quarter.

"And although sentiment is already at rock-bottom, there's a real basis for cautious optimism. First, if I'm right about oil, fuel costs won't rise appreciably in the third quarter. This huge headwind is dissipating.