AN EMB120 DURING THE R ENG PROP ANTI-ICE REPAIR IT WAS DISCOVERED THE PROP HUB HAD NEVER BEEN TORQUED PER THE JOB CARD.

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SCHEDULED MAINT: R PROP HUB CHANGE DUE FOR OVERHAUL. PROP IS MANUFACTURED BY HAMILTON STANDARD MODEL #14RF-9. TECHNICIANS ARE AUTH TO DISASSEMBLE AND REASSEMBLE COMPONENTS OF THIS PROP IN ORDER FOR A HUB TO BE INSTALLED ONTO A PROP FLANGE ON AN ENG THE PROP BLADES AND ACTUATOR MUST BE REMOVED TO MAKE THE HUB MANAGEABLE FOR INSTALLATION. UPON MOUNTING THE HUB ONTO THE PROP FLANGE ON THE ACFT ENG; 12 NUTS NEED TO BE INSTALLED TO PREVENT THE HUB FROM FALLING OFF OF THE FLANGE. THE WORK CARD PRESENTLY BEING USED AT OUR FACILITY IS TITLED 'PROP REMOVAL/INSTALLATION.' THE STEP ON THIS CARD THAT REFERS TO HUB TO FLANGE MOUNT STATES TO TORQUE THE 12 NUTS AT THIS POINT. NO WORK CARD IS PRESENTLY AVAILABLE AT OUR FACILITY FOR INSTALLATION OF A HUB WITHOUT THE BLADES AND OR ACTUATOR INSTALLED ON THE HUB. TO TORQUE THE 12 NUTS ONTO THE HUB/FLANGE WITHOUT A PROP BLADE INSTALLED IS IMPOSSIBLE. THE PROP BLADE IS USED BY THE MECH TO PROVIDE LEVERAGE AGAINST THE TORQUEING ACTION ON THE NUTS. THE 12 HUB NUTS WERE INSTALLED BY WRENCH BUT NOT TORQUED; DUE TO NO PROP BLADE BEING INSTALLED TO LEVERAGE AGAINST; THEN THE 4 PROP BLADES AND ACTUATOR WERE INSTALLED AND THE PROP BALANCED AND THE ACFT RELEASED FOR REVENUE FLT. 10 DAYS LATER UPON ACFT ARR IN ZZZ PLT RPTED R PROP HEAT INOP. LINE MECH LOOKED INTO PROB; FOUND HVY OIL LEAK CONTAMINATING DEICE BRUSH BLOCK. ACFT BROUGHT TO HANGAR FOR FURTHER INSPECTION. INVESTIGATING MECHS FOUND HUB/FLANGE NUTS NOT COMPLETELY TIGHT AGAINST PROP FLANGE ALLOWING OIL LEAKAGE AT PROP FLANGE TO PROP 'O' RING. PROP REMOVED TO FURTHER INVESTIGATE; FOUND WEAR ON HUB STUD THREADS AND DOWEL PIN HOLES AND WEAR IN PROP FLANGE HOLES AND STUDS. REPAIR ACTIONS: REPLACED ENG AND PROP ASSEMBLY. HUMAN FACTORS: THE MECH FORGOT TO COMPLETE TORQUEING OF NUTS BUT SIGNED WORK CARD AS HAVING DONE SO. I SIGNED BEHIND HIM STATING THAT HE HAD TORQUED THE NUTS BECAUSE HE STATED HE HAD. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE PROP HUB WAS ASSEMBLED PER THE JOB CARD EXCEPT WHEN THE PROP HUB WAS POSITIONED ON THE PROP FLANGE AND TORQUEING THE 12 NUTS TO 135 FT LBS WAS REQUIRED. THE RPTR SAID WHILE NOT IN THE JOB CARD THE NORMAL PRACTICE IS TO PUT AT LEAST 1 PROP BLADE ON THE PROP HUB AND FLANGE TO ALLOW LEVERAGE TO TORQUE THE HUB BOLTS. THE RPTR SAID IN THIS CASE THE TECHNICIAN TORQUED THE HUB BOLTS AS TIGHT AS A HAND WRENCH COULD ACHIEVE THINKING THE NUTS COULD BE RETORQUED AFTER THE BLADES WERE ADDED AT A LATER STEP PER THE JOB CARD. THE RPTR STATED THE RETORQUE WAS MISSED DURING A LATER SHIFT DUE TO THE 8 STEP PORTION OF THE CARD INCLUDING THE TORQUE WAS SIGNED OFF. THE RPTR SAID THE CARD HAS NOW BEEN CORRECTED TO READ THE REAL WORLD. CALLBACK CONVERSATION WITH RPTR ON ACN 465279 REVEALED THE FOLLOWING INFO: THE RPTR STATED THE JOB CARD DID NOT ALLOW FOR INSTALLING THE PROP BLADES OR BLADE TO ALLOW TORQUEING OF THE HUB BOLTS. THE RPTR SAID THE JOB CARD HAS BEEN REVISED TO ADD THIS PROC.