JetBlue Airways is tacking on an extra fee for checked bags on peak travel days in an effort to improve profitability.  The New York-based carrier told FOX Business that it will charge an extra $5 for the first bag checked, followed by an additional $10 for the second bag during high-traffic periods.For JetBlue, the cost for Blue Basic, Blue and Blue Extra travelers to check their first bag within 24 hours of departure rose to $45.  The cost for a second checked bag within 24 hours of departure also increas ...