As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TUL - CREW REPORTED NOSE LANDING GEAR WOULD NOT RETRACT AFTER TAKEOFF. FLIGHT RETURNED TUL LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. FOUND STRUT FLAT. REPLACED NOSE LANDING GEAR STRUT SCHRADER VALVE AND SERVICED STRUT. PERFORMED FIVE GEAR SWINGS AND NO LEAKS NOTED. SYSTEM GROUND CHECKED NORMAL OPERATION.