Narrative:

On the night of dec/xa/00, I was involved in a job to remove and replace the upper and lower torque links on the #2 main landing gear of aircraft xyz. I removed and replaced the links and signed off the discrepancy write-up. On the morning of dec/xb/00, the aircraft was en route from ZZZ, us, to baltimore, md. The pilot called into maintenance control and reported a weight on wheels [ground sensing] light on takeoff. The aircraft was ferried from bwi to ZZZ airport and the mechanics discovered, after some time, that the upper torque link required a bracket to sense the 'near' condition of the gear when extended. The mechanic installed the bracket and readjusted the weight on wheels sensors. One reason why this happened is that the upper torque links in our parts system are under the same class control number and the links had 2 different dash numbers (C-1 and -3). The -1 required a bracket, where the -3 was made thicker (to eliminate the bracket). I mistook both links to be the same (visibly no difference, unless one closely looks at it). One way to eliminate this problem would be to assign 2 different control numbers or install a tag on the -1 stating that it requires a bracket for weight on wheels sensing.

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Original NASA ASRS Text

Title: A DEHAVILLAND-8-100 WAS DISPATCHED IN NON COMPLIANCE WITH THE WT ON WHEELS SENSOR TARGET NOT INSTALLED.

Narrative: ON THE NIGHT OF DEC/XA/00, I WAS INVOLVED IN A JOB TO REMOVE AND REPLACE THE UPPER AND LOWER TORQUE LINKS ON THE #2 MAIN LNDG GEAR OF ACFT XYZ. I REMOVED AND REPLACED THE LINKS AND SIGNED OFF THE DISCREPANCY WRITE-UP. ON THE MORNING OF DEC/XB/00, THE ACFT WAS ENRTE FROM ZZZ, US, TO BALTIMORE, MD. THE PLT CALLED INTO MAINT CTL AND RPTED A WT ON WHEELS [GND SENSING] LIGHT ON TKOF. THE ACFT WAS FERRIED FROM BWI TO ZZZ ARPT AND THE MECHS DISCOVERED, AFTER SOME TIME, THAT THE UPPER TORQUE LINK REQUIRED A BRACKET TO SENSE THE 'NEAR' CONDITION OF THE GEAR WHEN EXTENDED. THE MECH INSTALLED THE BRACKET AND READJUSTED THE WT ON WHEELS SENSORS. ONE REASON WHY THIS HAPPENED IS THAT THE UPPER TORQUE LINKS IN OUR PARTS SYS ARE UNDER THE SAME CLASS CTL NUMBER AND THE LINKS HAD 2 DIFFERENT DASH NUMBERS (C-1 AND -3). THE -1 REQUIRED A BRACKET, WHERE THE -3 WAS MADE THICKER (TO ELIMINATE THE BRACKET). I MISTOOK BOTH LINKS TO BE THE SAME (VISIBLY NO DIFFERENCE, UNLESS ONE CLOSELY LOOKS AT IT). ONE WAY TO ELIMINATE THIS PROB WOULD BE TO ASSIGN 2 DIFFERENT CTL NUMBERS OR INSTALL A TAG ON THE -1 STATING THAT IT REQUIRES A BRACKET FOR WT ON WHEELS SENSING.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.