As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT - FLT 115, ENROUTE PIT-SEA, NR 1 ENGINE BEGAN TO VIBRATE. REDUCTION IN POWER DID NOT ELIMINATE THE VIBRATION. FLIGHT RETURNED TO PIT AND LANDED WITH NO FURTHER INCIDENT. ENGINE WAS NOT SHUT DOWN IN FLIGHT. MAINTENANCE INSPECTED THE ENGINE INLET AND EXHAUST SECTIONS, AND FOUND THE RUBBER SEALS ON THE ANNULUS FILLERS TO BE OUT OF POSITION. THE STRIPS WERE REPOSITIONED. (M)