A B757-300 WAS DISPATCHED IN NON COMPLIANCE WITH 1 ENG PRESSURE RATIO SYS INOP USING INCORRECT MEL WT LIMITS.

Narrative

ACFT X WAS RELEASED ZZZ-ZZZ1; A B757-300. 1 OF 2 ENG PRESSURE RATIO (EPR) SYS ON THE ACFT WAS DEFERRED. THE MEL REF IS 77-11-01. PENALTIES WERE APPLIED AS STATED IN THE REF PAGES OF OUR MEL MANUAL. THE PENALTIES WERE APPLIED PROPERLY; HOWEVER; THE WT PENALTIES WERE FOR B757-200 WITH RB211-535E4 ENGS; NOT FOR THE B757-300'S WITH RB211-535E4C ENGS. THE DATE OF THE MEL PAGE I REFED WAS FEB/XA/97. ACR X BEGAN ACQUIRING THE B757-300'S THE SUMMER OF 2001. THE B757 MEL MANUALS WERE NEVER UPDATED TO REFLECT THE ADDITION OF THE -300. THEREFORE; SINCE THERE WAS NO DESIGNATION OF WHETHER THE PENALTIES SHOULD BE APPLIED TO THE -200'S AND THE -300'S; IT WAS ASSUMED THE COMPANY HAD REVIEWED THE DATA IN THE MANUALS AND WERE CORRECT FOR BOTH VERSIONS OF THE ACFT. THE ERROR WAS DISCOVERED BY AN FAA INSPECTOR UPON ACFT X ARR INTO ZZZ1 WITH IMMEDIATE EFFECT. B757-300'S ARE NOT TO BE DISPATCHED WITH MEL CODE 77-11-01 UNTIL THE PROPER DATA HAS BEEN REVIEWED AND ENTERED INTO THE COMPANY'S MEL MANUAL. ACTIONS ARE TAKING PLACE CONCERNING THIS MEL ITEM; AND THE PROPER DATA WILL BE PROVIDED IN THE COMPANY MANUALS.