As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLAPS FAIL AT 25 WHEN SELECTING FLAPS TO 30 FROM 20. EMERGENCY VEHICLES WERE ON STANDBY AS A PRECAUTION (SKEW DETECTION SYSTEM). REMOVED AND REPLACED FLAP POWER DRIVE UNIT IAW AMM 27-52-01. FLAPS OPERATE NORMALLY AT ALL SELECTED POSITIONS.