2 B767-200 ACFT WERE DISPATCHED AND OPERATED IN NON COMPLIANCE WITH A LOWER BODY STRINGER REPAIR ACCOMPLISHED USING THE INCORRECT DETAIL IN THE STRUCTURAL REPAIR MANUAL.

Narrative

I WOULD LIKE TO RPT A SIT THAT AROSE DURING THE C-CHK MAINT OF ACR B767 ACFT AT THE ZZZ MAINT CTR. ACFT XYZ ARRIVED AT ZZZ APPROX APR/XA/99. DURING ACFT XYZ C-CHK; CORROSION TO NUMEROUS STRINGERS WAS FOUND IN THE AFT PIT BILGE AREA. REPAIR OF THESE STRINGERS WAS ACCOMPLISHED USING THE BOEING STRUCTURAL REPAIR MANUAL (SRM); WHICH IS A HAT CHANNEL SPLICE REPAIR. ACFT WAS RELEASED TO SVC. ACFT ABC ARRIVED AT ZZZ APPROX MAY/ZB/99 FOR A C-CHK. AGAIN; CORROSION WAS FOUND TO STRINGERS IN THE SAME AREA. REPAIR WAS ACCOMPLISHED USING THE SAME STRUCTURAL REPAIR MANUAL DETAIL. AT THIS POINT A ZZZ ACFT INSPECTOR DISAPPROVED THE DETAIL III REPAIR; STATING THAT THE STRUCTURAL REPAIR MANUAL REQUIRES DETAIL IV U-CHANNEL AND J CHANNEL REPAIR. THIS DISAPPROVAL 'RECHK' WRITE-UP WAS ADDRESSED BY THE ZZZ ENGINEERING DEPT AND THE ZZZ INSPECTION MGMNT TEAM. THEIR FINDING WAS THAT EITHER DETAIL III OR IV IS AN ACCEPTABLE REPAIR. ACFT ABC WAS RELEASED TO SVC. ACFT WXX ARRIVED AT ZZZ APPROX MAY/JJ/99. AGAIN; CORROSION WAS FOUND AND REPAIRED USING DETAIL III. AGAIN; A ZZZ ACFT INSPECTOR DISAPPROVED THIS REPAIR. AT THIS TIME; ZZZ ENGINEERING CHANGED THEIR INTERP OF STRUCTURAL REPAIR MANUAL AND ISSUED AN ENGINEERING VARIATION AUTH TO MODIFY THE DETAIL III REPAIR TO CONFORM WITH DETAIL IV. AS OF JUN/XA/99 I LEARNED THAT THE ACR B767 FLEET ENGINEER AND BOEING REGARD DETAIL IV TO BE THE ONLY ACCEPTABLE REPAIR. I FEEL THAT MYSELF; OTHER INSPECTORS; AND ZZZ INSPECTION MGMNT TEAM LEADERS APPROVED DETAIL III REPAIRS IN ERROR BASED ON A SOMEWHAT VAGUE STRUCTURAL REPAIR MANUAL AND INCORRECT ENGINEERING INSTRUCTIONS. I NOW UNDERSTAND THE INTENT OF THIS STRUCTURAL REPAIR MANUAL FOR FUTURE REPAIRS. ALSO WE (INSPECTORS) ARE ACTIVELY STRESSING OUR CONCERNS REGARDING ACFT XYZ AND ABC DETAIL III REPAIRS TO INSPECTION MGMNT; ENGINEERING DEPT; AND QUALITY ASSURANCE.