What was found
DURING TAXI NLG TRUSS SEPARATED FROM ACFT. DISCOVERED DURING RECORDS INSPECTION, IN 1999 THE TRUSS WAS R & R WITH A TRUSS WITH STOPS INSTALLED. THE ENTRY READS, REPLACED TRUSS WITH PN L540041-501. THE TAG READS REPLACED BENT TUBES, ADD STOPS, HEAT TREAT. THE TRUSS WAS TAKEN TO ACFT MFG FOR A ROCKWELL "C" HARDNESS TEST. THE REQUIRED HARDNESS READING SHOULD BE ROCKWELL "C" 38-41. THE ACTUAL TEST SHOWED READING AS LOW AS 23.5, THUS FALLING BELOW REQUIRED LIMITS. THE IMPROPER HEAT TREATING COULD HAVE LED TO THE TRUSS FAILURE. APPEARS TO PUT AN L IN THE FRONT OF THE PART NUMBER.