What was found
LAS - FLT 131 - AIR-TURN-BACK, STICK SHAKER ACTIVATED AT ROTATION (139K) AND CONTINUED THROUGH 240K, THEN OFF. ON AGAIN AT 280K, THEN INTERMITTENT. ON RETURN TO LAS, STALL WARNING SWITCH WOULD SOMETIMES STOP SHAKER. REMOVED AND REPLACED LEFT ANGLE OF ATTACK SENSOR. ALL FLAP SETTINGS WITHIN TOLERANCE, SYSTEM TESTS NORMAL. REMOVED AND REPLACED P5-18 STALL WARNING PANEL. STALL WARNING TESTED GOOD. (M)