What was found
AT CRUISE, CAPTAIN'S ALTIMETER FLUCTUATES +/- 40 FEET IN SMOOTH AIR AND FO'S ALTIMETER IS STEADY. REPLACED NR 1 ADC IAW MM 34-13-01, OP CHECKS GOOD.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
AT CRUISE, CAPTAIN'S ALTIMETER FLUCTUATES +/- 40 FEET IN SMOOTH AIR AND FO'S ALTIMETER IS STEADY. REPLACED NR 1 ADC IAW MM 34-13-01, OP CHECKS GOOD.