What was found
CRACKED U CHANNEL IN AFT LH CENTER WING SECTION STATION 2380, AS FLAGGED. REPLACED CRACKED STIFFENER WITH NEW. SEE 337 DATED 03/11/2025 FOR FURTHER INFO. FAA FORM 337 STATES: FOUND CRACK IN STIFFENER ON THE LEFT CENTER WING AFT BEAM AT W.S. 2380. CRACKED STIFFENER WAS REMOVED AND REPLACED WITH NEW, FABRICATED STIFFENER MADE FROM 2024-T3 ALUMINUM, 0.032" THICK TO SAME DIMENSIONS AS PREVIOUSLY INSTALLED. REPLACEMENT STIFFENER WAS ALODINED, THEN PRIMED WITH SUPER KOROPON 511K011 AND INSTALLED USING MS20470AD RIVETS AND CR3213 BLIND FASTENERS. ALL WORK WAS PERFORMED WITH REFERENCE TO CASA 212 SRM SECTION II FIG 2.38. CONTINUED AIRWORTHINESS WILL BE MAINTAINED IN ACCORDANCE WITH CURRENT INSPECTION PROGRAM OR AIRCRAFT MANUFACTURERS INSPECTION PROGRAM.