A PIPER PA31 LANDED GEAR UP INCURRING DAMAGE TO THE ACFT. CAUSED BY INCORRECT INSTALLATION OF CTL HANDLE CABLE TO HYD PWR UNIT.

Narrative

DURING ROUTINE INSPECTION; IT WAS DETERMINED THAT THE PIN CONNECTING THE CTL CABLE TO THE HYD PWR PACK WAS SAFETIED INCORRECTLY. IN ORDER TO CORRECT THIS PROB; I HAD TO PULL THE PIN TO FACILITATE REMOVAL OF THE OLD WIRE AND INSTALLATION FO THE NEW SAFETY. AFTER THE NEW SAFETY WIRE WAS IN PLACE AND THE SAFETY STARTED; I REINSTALLED THE PIN AND FINISHED THE SAFETY. AFTER THE INSPECTION WAS COMPLETE; THE ACFT WAS RELEASED FOR SVC AND FLEW FOR OVER 50 HRS WITHOUT ANY INDICATION OF TROUBLE. ON THE LAST FLT WHEN THE PLT ATTEMPTED TO EXTEND THE GEAR THEY FAILED TO COME DOWN. AFTER SEVERAL ATTEMPTS TO EXTEND THE GEAR; IT WAS DETERMINED THAT THE PLT WOULD HAVE TO LAND WITH THE GEAR UP. INVESTIGATION REVEALED THAT THE PIN WAS STILL IN THE ARM OF THE PWR PACK AND SAFETIED AND THAT THE CLEVIS WAS NOT ATTACHED. THE ONLY WAY THAT I CAN SEE THAT THIS COULD HAVE HAPPENED IS IF BOTH ARMS OF THE CLEVIS WERE ON THE BACK SIDE OF THE ARM INSTEAD OF THE ARM OF THE PWR PACK BEING BTWN THE ARMS OF THE CLEVIS. IN THE FUTURE; THE COMPANY IS GOING TO USE A RII PROGRAM SO THAT CRITICAL ITEMS ARE LOOKED AT BY MORE THAN JUST THE PERSON DOING THE WORK. IT ALSO SEEMS THAT THE PWR PACK SHOULD INCORPORATE A SPRING SO THAT; IN THE EVENT OF LINKAGE FAILURE; THE SPRING WOULD RETURN THE LEVER ON THE PWR PACK TO THE DOWN POS CAUSING THE GEAR TO EXTEND.