Flight Attendants Reject US Air Proposal  NEW YORK (Reuters) - Flight attendants at US Airways  &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=UAIR.O target=/stocks/quickinfo/fullquote"&gt;UAIR.O&lt;/A&gt; on Sunday said they had rejected a new proposal by the  airline on cuts in wages and benefits which they said fail to  improve on sick leave and reserve policies.