What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) During climb and shortly after established on course, the gyro flag on the left HSI appeared, and the heading function failed on all associated heading indicators. The PIC declared an emergency to divert to the departure airport in VMC conditions and made an uneventful landing. An rmi was found to be faulty, and both rmi's were replaced as recommended.
As the FAA filed it
(-23) DURING CLIMB AND SHORTLY AFTER ESTABLISHED ON COURSE, THE GYRO FLAG ON THE LEFT HSI APPEARED, AND THE HEADING FUNCTION FAILED ON ALL ASSOCIATED HEADING INDICATORS. THE PIC DECLARED AN EMERGENCY TO DIVERT TO THE DEPARTURE AIRPORT IN VMC CONDITIONS AND MADE AN UNEVENTFUL LANDING. AN RMI WAS FOUND TO BE FAULTY, AND BOTH RMI'S WERE REPLACED AS RECOMMENDED.