What was found
M1 HAS DISCOVERED A DESIGN/ENGINEERING FLAW BETWEEN THE AMM 65-11-00, 4-9 FIGURE 1/1 SHEET 3/3 AND THE CURRENT MANUFACTURING OF THE TAIL ROTOR OUTPUT SHAFT WHICH IS QUITE POSSIBLY THE ROOT CAUSE OF DAMAGE TO THIS COMPONENT. M1 HAS REPEATEDLY DISCOVERED DAMAGE TO THE SPLINES ON LAKOTA TAIL ROTOR OUTPUT SHAFTS (6 SINCE 16 JANUARY 2023). THIS HAS BEEN AN ON-GOING ISSUE SINCE FORT NOVOSEL RECEIVED THESE AIRCRAFT. AFTER INSPECTING THE TAIL ROTOR SHAFTS, QUALITY SUPERVISION DOES NOT SUSPECT THIS IS A MAINTENANCE OR A TRAINING PROBLEM. THIS DAMAGE IS MORE LIKELY ATTRIBUTED TO THE DESIGN OF THE SPLINES OR A POTENTIAL DESIGN FLAW. QC MONITORS THIS PROCESS WITH A TECHNICAL INSPECTOR AND MECHANICS ARE FOLLOWING THE DOCTRINE. QC HAS INSPECTED THE TOOLING AND DOES NOT SEE A PROBLEM WITH THE INSTALLATION OR REMOVAL TOOLS NOR THE DOCUMENTED PROCESS OF THE REMOVAL OR INSTALLATION PROCEDURE. ADDITIONAL PHOTOS AND DOCUMENTS WILL BE SUBMITTED IN A SEPARATE EMAIL.