As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF THE CREW REPORTED THAT AFTER THE LG WAS RETRACTED THAT THE NLG DEPLOYED TO THE DOWN POSITION. TROUBLESHOOTING & INSPECTION FOUND THAT THE NLG HAD AN INTERNAL LEAK. THE INTERNAL LEAK IN THE STRUT WAS PREVENTING THE STRUT FROM FULLY EXTENDING AFTER TAKEOFF & THIS PREVENTED THE STRUT FROM ENGAGING GEAR UPLOCK HOOK. THE STRUT ASSEMBLY WAS REMOVED & AN OVERHAULED ASSEMBLY WAS INSTALLED. RETURNED TO SERVICE.