As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT RETURNED TO FIELD DUE TO SLAT INDICATION PROBLEM. *S/D* GREASE AND GRIME ON SLAT NR 5 PROXIMITY SENSOR, S280 CAUSED THE FALSE INDICATION. THE SENSOR WAS CLEANED AND ADJUSTED, ACCOMPLISHED TARGET AND SENSOR BITE TEST AND FOUND NO DISCREPANCIES. OPERATED FLAPS SEVERAL TIMES AND PERFORMED BITE TEST OF FSEU, FOUND NO FAULTS. GROUND CHECKS NORMAL.