As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STANDBY DRIFT LEFT BANK UP TO 12' AND DOWN 11' PERFORM A ERECT ALIGN AND FAST ALIGN IN FLT, INSTRUMENT IMPROVE BUT STILL INDICATED A L BANK OF 5' TO 7' IN LEVEL FLIGHT.A/C PERFORMED AIR TURN BACK (ATB) , AND MTX GROUNDED A/C . TROUBLESHOT AND REMOVE AND REPLACED ESIS IAW SUP AMM 34-25-00 AND REA 3425-66044-- C/W OPS CHECK GOOD. MTX RETURNED A/C TO SERVICE.