JetBlue Profit Tumbles, Misses Estimates  NEW YORK (Reuters) - JetBlue Airways Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=JBLU.O target=/stocks/quickinfo/fullquote"&gt;JBLU.O&lt;/A&gt; on  Thursday said third-quarter earnings fell 71 percent, missing  analysts' lowered estimates, as it struggled with skyrocketing  fuel prices, storm disruptions and competition.