ATA Files for Bankruptcy  LOS ANGELES (Reuters) - ATA Holdings Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=ATAH.O target=/stocks/quickinfo/fullquote"&gt;ATAH.O&lt;/A&gt;, parent  of struggling low-cost carrier ATA Airlines, on Tuesday filed  for Chapter 11 bankruptcy protection as falling fares and  soaring fuel prices drained it of cash.