What was found
AFT DRAIN MAST AND FUSELAGE AT ATTACH POINT IS CORRODED. MARKED. REPAIRED AFT FUSELAGE SKIN F.S. 1661-1681 S25R-26R IAW AMES REA 47518REA01 REV A AND UAL ECRA 5360-01663.INSTALLED A NEW DRAIN MAST PN 75-3831-3-0004 IAW B757 AMM 28-31-01-404. REPAIRED AFT FUSELAGE SKIN F.S. 1661-1681 S25R-26R IAW AMES REA 47518REA01 REV A AND UAL ECRA 5360-01663.INSTALLED A NEW DRAIN MAST PN 75-3831-3-0004 IAW B757 AMM 28-31-01-404.