As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IRS 3 ON POS IAW 2 - 4 SHOWED AN INCREASING ACTUAL MILEAGE THROUGHOUT THE FLIGHT. DIS OF IRUS WAS GROSSLY DIFFERING IN BEARING. UP TO 140 DEGREES DIFFERENCE RT INERTIAL IAW UNIT FAILS REMOVAL CHECK IAW FIG 107B, REPLACED RT IRU IAW AMM34- 21-401. ALSO PERFORMED MCDP TEST 30 IAW AMM 22-00-03 117. OPERATIONS CHECKED GOOD ACFT REMAINS FULL CAT CAPABLE AUTO LAND