As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6418 - IAD-BOS - TAKEOFF ABORTED DUE TO TAKEOFF CONFIGURATION WARNING INDICATION. AIRCRAFT RETURNED TO THE GATE WHERE MAINTENANCE FOUND THE PARKING BRAKE SYSTEM WAS AT FAULT. MAINTENANCE ADJUSTED THE PARKING BRAKE MICROSWITCH. AIRCRAFT SYSTEM WAS THEN OPERATIONALL CHECKED AND THE AIRCRAFT WAS RELEASED FOR SERVICE. (M)