NO.2 ENGINE - N1 MODIFIER SCHEDULE CHANGE FOR CFM56-7826 AND CFM56-7827 ENGINES. SERVICE BULLETIN NOT APPLICABLE MOS MRS/MSC - ENC SB 72-0148 NO.2 ENGINE - SAFETYING OF OIL RETURN TUBE - INTRODUCTION OF A NEW BOLT PERMITTING INSTALLATION OF COMPUED WITH - AT MANUFACTURE SAFETY WIRE. SERVICE BULLETIN MOS 16-DEC-1998 HRSAISC - 0