What was found
DURING THE STRUCTURE INSPECTION, IT WAS FOUND THE SIDEBOX BEAM FLANGE AT LH IN S15 FR 43 AREA WITH CRACK ACTION: PERFORMED PERMANENT REPAIR AT THE SIDEBOX BEAM FLANGE AT LH IN S15 FR 43 AREA PER ALLEGIANT EO # E5331-0009 AND E5331-0010. THIS EO, BASED ON SB A320–53–1251 REV 04, INTRODUCES A FULL LIFE SOLUTION FOR THE TORSION BOX LOWER SIDESHELL, LEFT SIDE. TESTS REVEALED THE POTENTIAL FOR FATIGUE ISSUES ON THE HORIZONTAL FLANGE OF THE TORSION BOX. THIS EO (CONFIG 001 AND 002) PROVIDES THE DETAILS TO REPLACE THE OLD SMALL BRACKET WITH A NEW INTEGRAL BRACKET, EMBODIMENT OF THIS MODIFICATION LOCALLY STRENGTHENS THE TORSION BOX. ACCOMPLISHMENT OF THIS EO/SB CANCELS THE INSPECTION REQUIREMENTS OF SERVICE BULLETIN A320-53-1258. THIS EO REPLACES EO 5331-02 WHICH WERE WRITTEN FOR THE PREVIOUS SB REVISION.AD REQUIRES MODIFICATION OF THE AIRCRAFT ON OR BEFORE 48000TFC/96000TFH. THIS MODIFICATION MAY ALSO BE ACCOMPLISHED AFTER EXCESSIVE CRACK FINDINGS ON INITIAL INSPECTIONS