A DASH 8 WAS RETURNED TO SVC WITH A DAMAGED AILERON REAR SPAR.

Narrative

WHILE CHANGING A TAB FITTING ON THE REAR SPAR OF THE AILERON; I DENTED THE REAR SPAR WHILE TRYING TO GET THE OLD FITTING OFF. AT THE TIME I THOUGHT THE REAR SPAR WAS THICKER THAN IT IS AND DIDN'T CONSIDER IT A PROB THAT NEEDED FURTHER ATTN. I RECENTLY FOUND OUT THE REAR SPAR IS ONLY .025 INCHES THICK. HAVING FOUND THIS OUT; I TOLD THE BASE MGR WHAT HAD HAPPENED. HE HAD A QUALITY CTL INSPECTOR LOOK AT ANOTHER AILERON THAT WAS REMOVED FROM ANOTHER ACFT TO SEE IF THE REAR SPAR COULD BE TESTED FOR CRACKS FROM AN ACCESS HOLE. THE INSPECTOR SAID THAT THEY COULD EDDY CURRENT THE SPAR FOR CRACKS. THE BASE MGR IS GOING TO FIND OUT THROUGH RECORDS WHICH PLANE IT WAS AND HAVE THE AILERON REAR SPAR EDDY-CURRENTED. SINCE THIS HAPPENED APPROX 7-8 MONTHS AGO; I DON'T KNOW WHICH ACFT IT WAS OR WHICH AILERON IT WAS. HOW I FOUND OUT ABOUT THE SPAR THICKNESS IS THAT ANOTHER SHEET METAL MECH WAS CHANGING A FITTING IN THE SAME SPOT WHEN HE CRACKED THE REAR SPAR AND ENDED UP SPLICING IN A NEW SECTION OF THE REAR SPAR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS IDENTED AND THE AILERON WAS INSPECTED AND ONLY MINOR DAMAGE WAS NOTED. THE RPTR SAID THE SHOP PROCS WERE NOT CHANGED BUT EVERYONE WHO WORKS AILERONS IS AWARE OF THE SPAR PROB.