As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 754, ATL-PHL - ACRID SMELL NOTED DURING TAKEOFF BY PILOTS AND FLIGHT ATTENDANTS. PUNGENT SMELL UNTIL WELL AFTER TAKEOFF THRUST. ODOR SUBSIDED TO APPROXIMATELY 1500FT. NO COCKPIT INDICATIONS THRU 8000FT. IN DESCENT ODOR OCCURRED AGAIN. MAINTENANCE FOUND THE LEFT FORWARD AVIONICS FAN MAKING LOUD RUMBLE NOISE. REMOVED AND REPLACED AND PERFORMED SATISFACTORY OPERATIONAL CHECK.