As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ISI INSTUMENT STARTED TUMBLING DURING FLIGHT THEN BECAME STUCK SHOWING A 60 DEGREE BANK. AIRSPEED AND ALTITUDE INDICATIONS WERE NORMAL. RETURNED TO FILED AND ACCOMPLISHED UNEVENTFUL LANDING. REMOVED FROM SERVICE. REF WORK PERFORMED ON W/O 317849, N/R-00001. REPLACED ISI & LEAK CHECK NORMAL. OPS TEST NORMAL. ALL INDICATIONS READ NORMAL. NO FURTHER DEFECTS NORMAL. RETURNED TO SERVICE