As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON T/O CREW OF ANOTHER AIRCRAFT OBSERVED SMOKE (WHITE AT RST CHANGING TO DARK SMOKE) COMING OUT OF TAIL ON LEFT ENGINE DURING T/O ROLL AND CLIMBOUT. ALL COCKPIT INDICATIONS INDICATE NORMAL. PERFORMED VISUAL INSP OF INLET/ EXHAUST AND ENGINE EXTERIOR COMPONENTS. NO FOD, INSPECTED, RAN BOTH ENGINES TO T/O PWR, NO VIBS FELT AND ALL ENGINE PARAMETERS EVENLY MATCHED. RAN TO T/O PWR 5 TIMES, NO SMOKE NOTED. CONFERENCE CALL WITH ENG ANALYST AND SR COORDINATOR. OK FOR SERVICE.