What was found
DURING THE B6 BASIC CHECK AT EAMS, CORROSION DAMAGE WAS DISCOVERED INSIDE THE P/N 170-2365-01-404-109 AFT WI-FI (ATG) ANTENNA FITTING/SKIN DOUBLER. REFERENCE FIGURE 1 FOR DETAILS AFTER DAMAGE REMOVAL. THE AFT WI-FI (ATG) ANTENNA FITTING WAS INSTALLED BY STC ST03904AT AND CANNOT BE DISPOSITIONED BY EMBRAER. THIS EO IS BEING RELEASED TO REMOVE THE DAMAGED FITTING AND REPLACE IT WITH A NEW FITTING USING THE APPROVED INSTALLATION DRAWINGS FROM THE STC AS A REFERENCE. THEREFORE, AFTER INSTALLATION OF THE NEW FITTING THE RESULTING CONFIGURATION WILL BE THE SAME AS THE ORIGINAL STC INSTALLATION AND THE SUPPLEMENTAL INSPECTION OF THE AFT WI-FI (ATG) ANTENNA FITTING REQUIRED BY THE STC REMAIN VALID. THIS INSPECTION IS BEING FORECASTED BY COMPASS EO E175-53MA-003.2 AND THE INITIAL INSPECTION WILL BE DUE 17,700 CYCLES AFTER THE ORIGINAL INSTALLATION OF THE AFT WI-FI (ATG) ANTENNA ON AIRCRAFT 619CZ BY COMPASS EO E175-53MA-003 REV 2. COMPASS ENGINEERING HAS CLASSIFIED THIS AS A MAJOR REPAIR. EO E175-53MR-470 IS BEING ACCOMPLISHED UNDER WO 2791915