What was found
LANDING GEAR WOULD NOT EXTEND ELECTRICALLY ON APPROACH. OPERATIONS NORMAL WHEN LANDING GEAR EXTENDED WITH MANUAL EMERGENCY EXTENSION SYS. FOUND LANDING GEAR ACTUATOR MOTOR INOPERATIVE. WOULD MAKE NOISE BUT NOT ROTATE. REPLACED MOTOR WITH OVERHAULED REPLACEMENT UNIT; LANDING GEAR SYS OPERATIONS NORMAL. CLEANED CORROSION FROM BATTERY TERMINALS, SUSPECT VOLTAGE DROP UNDER LANDING GEAR OPERATIONS LOAD MAY HAVE CONTRIBUTED. TRANSIENT AC, RECORDS NOT AVAILABLE TO VERIFY MOTOR TIME IN SERVICE. (K)