What was found
PILOT REPORTED THAT THE RIGHT HAND (CO-PILOT'S) AIRSPEED INDICATOR WAS INTERMITTENT. AIRCRAFT RETURNED BACK TO ANCHORAGE FOR AN UNSCHEDULED LANDING, NO ISSUES WITH LANDING. MAINTENANCE PERSONAL REMOVED AND REPLACED THE RIGHT HAND (CO-PILOT'S) AIRSPEED INDICATOR, SYSTEM OPERATIONAL CHECK SUCCESSFUL, AIRCRAFT RETURNED TO SERVICE.