MD80 CAPT RPTS MISSING AILERON TRIM POINTERS IN THE AILERON TRIM INDICATOR ON MANY ACFT.

Narrative

I ARRIVED AT THE GATE AND WAS TOLD BY A MECHANIC WHO WAS LEAVING THE AIRCRAFT THAT THE AILERON TRIM POINTER WAS MISSING. I LOOKED IN THE LOGBOOK TO SEE IF IT WAS WRITTEN UP AND FOUND THAT IT WAS NOT. I THEN WROTE IT UP. THE TRIM POINTER WAS REPLACED SUBSEQUENT TO DEP. SOME BACKGROUND MIGHT BE HELPFUL. I'VE FOUND THESE TRIM POINTERS MISSING ON ABOUT TEN ACFT OVER THE LAST TWO MONTHS AND HAVE WRITTEN EACH OF THEM UP. I'VE WRITTEN THESE UP SO MANY TIMES THAT I'VE QUITE SIMPLY LOST TRACK OF NUMBERS. ON AT LEAST TWO OCCASIONS I'VE WRITTEN THIS UP TWO TIMES ON TWO DIFFERENT AIRPLANES ON THE SAME DAY. ON ONE ACFT I FOUND THAT THE MOUNTING TANG FOR THE POINTER WAS PAINTED WITH WHITE PAINT AND I FLEW THAT ACFT AND STILL DON'T KNOW IF THIS IS ACCEPTABLE. I DID NOT WRITE THAT UP. THIS IN HINDSIGHT WAS AN OVERSIGHT ON MY PART. GIVEN ENOUGH TIME I GUESS I'LL GET THROUGH THE ENTIRE FLEET. MAINT NEEDS TO GO TO EACH MD80 AND DETERMINE IF THE TRIM POINTER IS IN PLACE. IF NOT THEN IT SHOULD BE REPLACED.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR BELIEVES THAT AN ADHESIVE PROB IS CAUSING THE POINTERS TO FALL OFF. THE TANG TO WHICH THE POINTER IS FASTENED IS NOT VISIBLE ON SOME ACFT THAT HAVE THE SCALE BACKGROUND PAINTED THE SAME COLOR AS THE TANG.