** Alliance Aviation Services AQZ.AX jumps 8.8% to A$2.35; on track for best day since April 30
** Stock among top 10 gainers on ASX All Ordinaries index .AORD
** Aviation services co strikes A$62.3 mln ($40.4 mln) deal with U.S.-based private co Beautech Power Systems for sale of 12 General Electric CF34-10 engines
** About 85,999 shares traded, 1.1x the 30-day avg
** AQZ falls 20.5% YTD
($1 = A$1.5434)
(Reporting by Jasmeen Ara Shaikh in Bengaluru)
((JasmeenAraIslam.Shaikh@thomsonreuters.com;))