What was found
AIRCRAFT WAS GNDED. EMER DECLARED, LANDING UNEVENTFUL & ACFT NOT OVERWEIGHT. DURING CLIMB, WHEN FLAPS SET TO 5 THE NR 3 LE IN TRANSIT LIGHT ILLUMINATED, THEN EXTINGUISHED. INDICATION RETURNED & REMAINED UNTIL FLAPS 15 SELECTED. INDICATION RETURNED TWICE DURING APPROACH WITH FLAPS AT 15. FOUND LE FLAP NR 3 EXTEND SENSOR STRINGER 173, IMPEDANCE OUT OF LIMITS. R & R SENSOR IAW AMM 27-88-11. SYS CHECKED NORMAL.