What was found
(CAN) THE SEAT BELT SHOULDER STRAP CHAFED ON A RETAINING BRACKET FOR THE SEAT BACK COVER ON THE PILOTS SEAT. THE CHAFING OCCURRED DURING RETRACTION AND EXTENSION OF THE INERTIA REEL OVER A PERIOD OF TWO MONTHS AND SEVERAL FLIGHTS. THE BRACKET IN QUESTION HAD SHARP EDGES WHICH IS NOT THE NORM FOR THIS PART. IT ALSO HAS A LARGER RADIUS ON ONE OF THE TWO BRACKETS USED FOR HOLDING THE PILOT'S SEAT BACK COVER IN POSITION. REPLACED THE INERTIA REEL ASSEMBLY WITH A NEW UNIT AND SMOOTHED OUT THE EDGES OF THE SUSPECT BRACKET WHICH CUT INTO THE SHOULDER BELT. THE SYSTEM HAS BEEN TESTED, HQ NOTIFIED, AND WE SHALL BE KEEPING A REGULAR WATCH ON THIS AREA AS IS OUR NORM .