What was found
DFW - FLT 556 - AFTER TAKEOFF DFW WHEN LANDING GEAR RETRACTED, RECEIVED NOSE GEAR ALERT. RECYCLED LANDING GEAR SEVERAL CYCLES AND INDICATIONS NORMAL ON EXTENSION, BUT WIND NOISE EVIDENT FROM NOSE GEAR AREA WHEN GEAR RETRACTED. EXTENDED LANDING GEAR AND AIRCRAFT RETURNED TO DFW, LANDING WITHOUT INCIDENT. REPLACED NOSE LANDING GEAR DOOR SELECTOR VALVE AND NOSE LANDING GEAR SEQUENCE VALVE. ACCOMPLISHED NOSE LANDING GEAR RETRACTION CHECK WITH NO DEFECTS FOUND. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)