What was found
DURING FLIGHT, THE LEFT HEADING COMPAROTOR CAME ON DURING FLIGHT, COULDN'T RESET. AIRCRAFT RETURNED TO DTW. MAINTENANCE REPLACED THE NR 1 AHRS. SYSTEM TESTS IAW SF340 MM34.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
DURING FLIGHT, THE LEFT HEADING COMPAROTOR CAME ON DURING FLIGHT, COULDN'T RESET. AIRCRAFT RETURNED TO DTW. MAINTENANCE REPLACED THE NR 1 AHRS. SYSTEM TESTS IAW SF340 MM34.