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 IAW AMM 73-11-02 AND REPLACED FUEL FILTER DIFFERENTIAL PRESSURE SWITCH (AALA202104199043) IAW AMM 73-34-01 ON # 1 ENG, LEAK AND OPS CHECK GOOD.