2-53-00) - REPLACEMENT OF LPT STAGE 1 NOZZLE SEGMENTS DUE TO ENVIRONMENTAL DISTRESS, SERVICE BULLETIN MOS 22-JUL-2013 HRSIMSC - ENC SB 72-0929 NO.2 ENGINE - HP TURBINE ROTOR ASSEMBLY (72-52-00)- HPT ROTOR DISK AIR SLOT REDESIGN. SERVICE CUSTOMER BULLETIN CONVENIENCE MOS 06-AUG-2013 HRS/MSC - ENC SB