What was found
ON TAKEOFF FLAPS (20) WOULD NOT RETRACT TO ZERO. FLAP HANDLE WOULD NOT MOVE FROM DETENT. UPON LANDING AND SHUTDOWN, FLAPS THEN RETRACTED NORMALLY. OPERATED FLAPS NUMEROUS CYCLES AND FOUND NO FAILURE, HOWEVER, FOUND THE FLAP HANDLE SIDE GUARDS LOOSE. REMOVED FLAP HANDLE AND TIGHTENEND SIDE GUARDS, REINSTALLED FLAP HANDLE ASSY FLAPS. OPS CHECK GOOD IAW THE MODEL 650 MM 27-54-01.