What was found
ON TAKEOFF ROLL, THE CAPTS AIRSPEED IND FAILED. VMO AIRSPEED MACH FLAGS IN VIEW, & AIRSPEED POINTER OFF SCALE & INOP IND VIEW, REJECTED TAKEOFF BELOW 100 KTS. MAINT PERFORMED A BITE TEST OF LT ADC IAW BMM. R & INSP CONNECTOR TO CAPTS AIRSPEED IND, NO DEFECTS NOTED, OPS CHECK GOOD. A FOLLOW-UP WRITTEN TO REPLACE MACH SPEED IND. MAINT R & R CAPTS AIRSPEED IND IAW BMM, OPS CHECK WAS GOOD. FUNCTIONAL TEST OF MACH SPEED IND CONFIRMED FAILURE OF UNIT FOR FAILING SLEW RATE TEST. TEARDOWN REVEALED A BROKEN TORSION SPRING & AIR SPEED COUNTER, ALSO FOUND RESOLVER & AIR SPEED BACK GEARS WORN OUT. REPLACED DAMAGED PARTS, CLEANED CONTAMINATION FROM GEAR TRAIN AND BEZEL GLASS, CALIBRATED, AND PERFORMED FUNCTIONAL TEST.