A FOKKER 100 WAS DISPATCHED AND OPERATED WITH THE ALTERNATE LNDG GEAR HANDLE LOCK SOLENOID REPLACED. ENGINEERING ORDER REQUIRED REPLACEMENT OF THE NORMAL LNDG GEAR HANDLE LOCK SOLENOID. ERROR WAS CAUSED BY A PUB DEFICIENCY.

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ON MY SHIFT; I WAS ASSIGNED AN ENGINEERING ORDER (EO) PREPARED BY ACR TO REPLACE AN ELECTRICAL SOLENOID ON THE LNDG GEAR HANDLE IN THE COCKPIT. THE ENGINEERING ORDER WAS A DRAFT ENGINEERING ORDER AND A MINOR ALTERATION TO THE AIRFRAME. THE TITLE OF THE ENGINEERING ORDER DIDN'T CLRLY STATE THE HANDLE REQUIRING THE MODIFICATION. THE ACFT; XYZ; WAS IN HVY MAINT FOR A 'Q CHK.' THE SUBJECT FOR THE ENGINEERING ORDER WAS A LNDG GEAR-ANTI-RETRACT SOLENOID REPLACEMENT. THE ENGINEERING ORDER REPLACES THE CURRENT SOLENOID WITH A MORE RELIABLE SOLENOID. I WAS FAMILIAR WITH A SOLENOID ON THE ALTERNATE LNDG GEAR WHICH WAS KNOWN TO FAIL; LOCATED ON THE REAR OF THE PEDESTAL IN THE COCKPIT. I HAD REPLACED THAT SOLENOID IN THE PAST TO REPAIR OTHER ACFT. I DIDN'T KNOW THERE WAS ANOTHER SOLENOID ON THE NORMAL LNDG GEAR HANDLE LOCATED ON THE MAIN INST PANEL. THE ENGINEERING ORDER ASKED TO IDENT THE PART NUMBER OF SOLENOID (-1); WHICH WAS DONE. A NEW AND IMPROVED (-2) SOLENOID WAS INSTALLED. THE POLARITY OF THE WIRES WAS DETERMINED AND WIRES CONNECTED TO THE SOLENOID. NO TESTING OF THE SYS WAS REQUIRED. NO INSPECTION OF WORKMANSHIP WAS REQUIRED. ACFT LNDG GEAR WAS TESTED IN HANGAR; TEST FLOWN BEFORE ENTERING SVC; AND RETURNED TO SVC ON DEC/XB/98. THE NEXT ACFT WAS BROUGHT INTO THE HANGAR; AND THE 'Q CHK' STARTED. ANOTHER FELLOW WORKER WAS ASSIGNED THE SAME ENGINEERING ORDER ON DEC/XA/98. I OBSERVED HE WAS CHANGING A SOLENOID ON A DIFFERENT HANDLE THAN WHAT I HAD DONE ON THE PREVIOUS ACFT. I WAS PUZZLED AND ASKED TO READ THE ENGINEERING ORDER AGAIN. I DISCOVERED I HAD CHANGED THE WRONG SOLENOID. I SELF- DISCLOSED THE ERROR TO MY LEAD MECH; THE FOREMAN; AND ANOTHER FOREMAN THAT SAME SHIFT. THE ACFT WAS ROUTED BACK TO THE MAINT HANGAR THAT SAME DAY. THE ENGINEERING ORDER WAS CORRECTLY COMPLETED AND RELEASED FOR SVC BY SOMEONE OTHER THAN MYSELF. A REQUEST FOR ENGINEERING SVCS AT ACR HAS BEEN SUBMITTED TO REVISE THE ENGINEERING ORDER TO MODIFY BOTH LNDG GEAR HANDLES AND PURGE ALL (-1) SOLENOIDS FROM STOCK.