As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 3144 - AFTER TAKEOFF FROM DTW, THE NR 1 ALTIMETER AND ALTITUDE ALERTER FLAGGED. THE AIRCRAFT RETURNED TO DTW. MAINTENANCE WAS UNABLE TO DUPLICATE THE DISCREPANCY. AS A PRECAUTION, THE NR 1 ALTIMETER WAS REPLACED. SYSTEM OPERATED SATISFACTORILY. (Z)