What was found
ON T/O FROM PDX WHILE RETRACTING GEAR, HEARD A LOUD BANG AT FRONT OF A/C. LANDING GEAR HAD RETRACTED AT NORMAL SPEED AND NO ANOMALIES WITH LG OR A/C AFTER RETRACTION. LEG EXTENDED AND LOCKED NORMALLY ON APPROACH. LANDING UNEVENTFUL. REMOVED FROM SERVICE. PERFORMED GVI OF A/C FOR EVIDENCE OF BIRD STRIKES. NO DEFECTS NOTED. PERFORMED GVI OF NLG AND SURROUNDING AREA FOR DISCREPANCIES. NONE NOTED. CYCLED NLG DOORS. AUDIBLE NOISE WHEN DOORS CLOSE. NOISE NOT EXCESSIVE. A/C CLEAR FOR SERVICE.