As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORRODED HARDWARE FOUND ON A/C LEFT WING TOP SURFACE COMMON TO AILERON MIDDLE HINGE SUPPORT (C CHECK RO 12-31-21) INSTALLED NEW HARDWARE ON A/C LH TOP WING SURFACE COMMON TO AILERON MIDDLE HINGE SUPPORT REF: CRJ900 AMM. 20-21-00-910-801-A01 CALIBRATED TOOL #TUC5600 DUE CAL: 28 FEB 22