What was found
STL - FLT 585 - AFTER TAKEOFF WHEN LANDING GEAR WAS RETRACTED, NLG UNSAFE RED LIGHT REMAINED ILLUMINATED WITH INTERMITTENT WARNING HORN. CYCLED LANDING GEAR. FOUND ICE IN NLG STRUT SCHRADER VALVE, MFG PN B05076-2. REPLACED SCHRADER VALVE, SERVICED NOSE STRUT WITH OIL AND NITROGEN AND LANDING GEAR INDICATION CHECKED NORMAL. CHECK C - 12-22-95 - STL.