As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - THE CREW ELECTED AN AIR TURN BACK AFTER THE FLAPS STUCK IN THE 15 DEGREE POSITION. AFTER AN UNEVENTFUL LANDING, MAINTENANCE CHECKED THE FAULT SYSTEM IN THE MX MODE OF THE FLAP COMPUTER AND CLEARED FAULTS PER BRASKA MM CH27-50-00. OPS CHECK OF FLAPS COULD NOT DUPLICATE PROBLEM.