As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CRACK WAS FOUND DURING D CHECK VISUAL INSPECTION IN THE BACK SHOP. DISCOVERED THE MAIN SPAR CRACKED IN THE LOWER CHORD/WEB RADIUS COMMON TO THE OUTBOARD AFT FLAP TRACK ATTACH POINT. THE CIRCUMSTANCES UNDER WHICH IT OCCURED IS UNKNOWN. COULD BE FATIGUE OR AN EXCESSIVE FORCE AT THE OUTBOARD AFT FLAP TRACK.