What was found
AIRCRAFT WAS GROUNDED: IN FLIGHT SLAT #4 FAILED TO EXTEND. LE FLAPS TRANSIT LIGHT ILLUMINATED. FLAPS - TRAILING EDGE - WERE NORMAL FOLLOWING LE FLAPS TRANSIT LIGHT PROCEDURE AND WHEN A/C CONFIGURED FOR FLAPS 15 LANDING. CONDITION CORRECTED IT SELF. CREW RECONFIGURED TO FLAPS 30 LANDING. AFTER LANDING NO LE DEVICES RETRACTED WHEN FLAPS RAISED.LE FLAP TRANSIT LIGHT IS ILLUMINATED AGAIN. **SUPPLEMENTAL REPORT FOR AALA202203251109: REPLACED #3 SLAT ACTUATOR DUE TO A CRACKED LINE ON THE ACTUATOR THAT WAS FOUND TO BE LEAKING AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK PER AMM 27-81-41-100-801** (CLOSED)