What was found
(CAN) BOTH COTTERPINS FOUND WORN OFF OF FLAP CNTL LEVER ASSY DETENT MECHANISM PIN. SUBSEQUENTLY- WASHERS FELL OFF, AND PIN MIGRATED OUT OF LEVER ABOUT .50 INCH. DURING PIN MIGRATION, REMNANTS OF THE COTTERPIN LEFT INSIDE-,HOLE CONTACTED, DETENT ROLLER'S BORE STOPPING PIN FROM MOVING ANY FURTHER. IF PIN HAD COME ALL THE WAY OUT WITH FLAPS SELECTED OUT OF FULL RETRACT, FLAP CONTRO L SURFACES WOULD HAVE RETRACTED TO FULL UP. COTTERPIN HOLE EDGES NOT CHAMFERED, SHARP EDGES COMBINED WITH SOFT MATERIAL OF PINS COULD ACCOUNT FOR ABNORMAL WEAR AND FAILURE: OTHER FLEET A/C CHECKED AND ONE DETENT MECHANISM PIN FOUND WITH A COTTERPIN MISSING RESULTING IN PIN MIGRATING PARTIALLY OUT.