What was found
ON TAKEOFF, EN ROUTE, CAPTAINS AIRSPEED INDICATOR WAS INOPERATIVE, REJECTED TAKEOFF AT 80 KTS AND RETURNED TO GATE. MX ISSUED MEL 34-24, COND 1 (CAPT A/S INDICATOR INOP). WHEN ACFT ARRIVED MX R / R CAPTAINS AIRSPEED INDICATOR IAW BMM 34-12-21. TEARDOWN REPORT FOR MACH AIRSPEED INDICATOR S/N 681 CONFIRMED FAILURE OF UNIT FINDING AIRSPEED COUNTER STICKING. MX OVERHAULED UNIT, REPLACED LAMPS AND AIRSPEED MOTOR & PINS, AND ALSO ACCOMPLISHED SERVICE BULLETIN 2083-34-13, REV 4. CLEANED, CALIBRATED, AND PERFORMED OPERATIONAL TEST, UNIT RETURNED TO SERVICE IAW CMM 34-12-02.