3 DC10-10 ACFT WERE DISPATCHED AND OPERATED FOR NUMEROUS FLTS WITH THE IMPROPER NOSE LNDG GEAR LOCK LINKS INSTALLED.

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THE ABOVE IDENTED ACFT HAD AN INCORRECT PART NUMBER LOCK LINK INSTALLED ON THEM FOR NUMEROUS FLTS. THE CORRECT MANUFACTURER'S PART NUMBER FOR DC10-10 ACFT IS ABCYXYX-W OR ABCYXYX-X. THE LINKS INSTALLED ARE AS FOLLOWS: ACFT PXP -- MANUFACTURER'S PART NUMBER DXZZZ-W SERIAL NUMBER MXZY. ACFT PZP MANUFACTURER'S PART NUMBER DXZZZ-W SERIAL NUMBER MXZZ. ACFT PYP MANUFACTURER'S PART NUMBER DXZZZ-W SERIAL NUMBER MXZY. THE DXZZZ LINK HAS A BORE WHICH IS APPROX 0.060 INCHES LARGER THAN THE CORRECT LINK AND WHICH RESULTS IN EXCESSIVE CLRNC WITH THE MATING PARTS. A POSSIBLE FAILURE MODE OF INCORRECT MATING PARTS WOULD BE THE COLLAPSE OF THE NOSE LNDG GEAR. SUPPLEMENTAL INFO FROM 421759: BASED ON THE UNDERSTANDING THAT LOCK LINK ABCYXYX AND DXZZZ WERE INTERCHANGEABLE; I AUTHORIZED A REVISION TO ESO TO PUT DXZZZ ON BOTH LINKS. IT HAS HOW BEEN DETERMINED THAT THESE LINKS ARE NOT INTERCHANGEABLE. GEAR SHOP ALSO ADDED THIS ACR NUMBER TO THE ABCYXYX LINK WHEN IT WAS CHKED BY THE STORES DEPT. MANUFACTURER PREVIOUSLY HAD INDICATED THAT THE 2 LINKS WERE INTERCHANGEABLE.