What was found
APPROXIMATELY 7 TO 8 MINUTES PRIOR TO LANDING WITH POWER AT IDLE, NR 1 ENGINE FIRE WARNING SOUNDED FOR APPROXIMATELY 1/4 SECOND. THEN ABOUT 2 OR 3 MINUTES LATER, NR 1 ENGINE FIRE WARNING SOUNDED FOR ABOUT 1 SECOND. NO OTHER ABNORMAL INDICATIONS. ENGINE WAS NOT SHUT DOWN. OPENED COWLING, FOUND NO SHORTS. CLEANED CONNECTORS ON LOWER LOOP, TESTS OK. SHOOK DOWN WIRING ON ENGINE. COULD NOT DUPLICATE PROBLEM. NR 1 FIRE DETECTION TESTS GOOD.