What was found
DURING CLIMB, THE AIRCRAFT HAD A FAILURE MESSAGE, FLAPS LOCKED, RETURNED TO DEPARTURE. UNEVENTFUL LANDING. MAINTENANCE PERFORMED A FAULT ANALYSIS IAW TSM 27-51-00-810-820-A, REPLACED THE FLAP PCU IAW AMM 27-54-51 PB401. REMOVED AND REPLACED THE BLOCK-VALVE IAW TSM 27-51-00-810-802-A, AND AMM 27-54-53 PB401. PERFORMED OPERATIONAL TESTS, FOUND NORMAL.