As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOS - FLT 4383 - AFTER TAKEOFF, THE LEFT ENGINE CHIP DETECTOR WARNING ILLUMINATED. AIRCRAFT RETURNED TO BOS AND LANDED WITHOUT INCIDENT. MAINTENANCE FOUND LARGE AMOUNTS OF METAL ON DETECTOR. LEFT ENGINE WAS REPLACED. AIRCRAFT WAS RETURNED TO SERVICE. (M)