As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: CRACK IN INNER SKIN IS HORIZONTAL APPROXIMATELY 1 INCH IN LENGTH. FORWARD END OF CRACK IS LOCATED 2.7 INCHES AFT OF STIFFENER AND 0.6 INCHES BELOW NEAREST FASTENER HOLE. STA 663, STR 18L AND WATERLINE 0. PERFORMED A FLUSH DOUBLER REPAIR PER EA AND SRM.