As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FUEL FILTER BYPASS LIGHT ILLUMINATED IN FLIGHT FOR APPROXIMATELY FOUR MINUTES, THEN EXTINGUISHED; FLIGHT DECLARED EMERGENCY AND RETURNED TO FIELD. REPLACED FUEL FILTER DIFFERENTIAL PRESSURE SWITCH IAW AMM 73-34-01 AND REPLACED FUEL FILTER (AALA202104199044) IAW AMM 73-11-02 ON # 1 ENG, LEAK AND OPS CHECK GOOD.