What was found
IN A CLEAN CONFIGURATION, WITH FLAPS AND GEAR UP, AT FLIGHT LEVEL 410 AND A CRUISE POWER SETTING, WE RECEIVED AN AURAL HIGH-SPEED WARNING. THE AURAL WARNING LASTED APPROXIMATELY 15 SECONDS. AS SOON AS WE HEARD THE WARNING, THE THROTTLES WERE BROUGHT TO IDLE; HOWEVER, THE AIRCRAFT CONTINUED TO ACCELERATE. IN AN EFFORT TO SLOW THE AIRCRAFT, THE PILOT FLYING DEPLOYED THE SPEED BRAKES FOR APPROXIMATELY TEN SECONDS AT WHICH TIME THE ORAL WARNING SILENCED. UNFORTUNATELY, WE DO NOT REMEMBER THE INDICATED AIRSPEED, ONLY THE MACH NUMBER, WHICH INCREASED TO MACH 0.806. TECHS PERFORMED THE OVERSPEED INSPECTION/CHECK. ALL 3 PHASES OF THE INSPECTION WERE PERFORMED. NO DEFECTS OR DISCREPANCIES RELATED TO AN OVERSPEED CONDITION ARE NOTED. ALL WORK PERFORMED PER AMM 05-50-04-200-801A