As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6195 - IAD-MDT - DURING CRUISE, AIRCRAFT MADE AN UNSCHEDULED LANDING DUE TO CAPTAINS ALTIMETER FAILURE. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND REMOVED AND REPLACED CAPT'S ALTIMETER. OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)