As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6412 - PHX-COS, DECLARED AN EMERGENCY AND RETURNED TO FIELD DUE TO FLAPS SYSTEM FAILING AT DEGREES. MAINTENANCE HAD REPLACED THE LT INBOARD FLAP ACTUATOR THE NIGHT BEFORE FOR A PREVIOUS FAILURE. MAINTENANCE REMOVED AND REPLACED BPSU. MAINTENANCE COMPLIED WITH PART A ON 10/13 AND PART B ON 10/14. (M)