What was found
A/C N16999 FLIGHT 3071 FROM EWR AIR RETURN. L/G/AIR AIR GROUND FAIL AFTER TAKEOFF, GEAR WOULD NOT RETRACT. MAINTENANCE REMOVED AND REPLACED LANDING GEAR CONTROL LEVER RELAY K0024 AND SERVICED NOSE STRUT IAW EMB-145 AMM 32-32-02, 20-13-02 AND 32-20-01. OPERATIONAL CHECK WAS GOOD IAW 32-30-00, COULD NOT DUPLICATE. THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.