As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RTF SMOKE CABIN/COCKPIT AFT TRAN BLD TO ENG (CAPTAIN REPORTED THE SMOKE WAS COMING OUT OF VENTS IN CABIN AND WHEN CAPTAIN TURNED OFF NR 2 PACK THE SMOKE CLEARED). PERFORMED HIGH POWER RUNS AND PERFORMED RUNS ON PACKS WITH ALL BLEED SOURCES, NO DEFECTS FOUND. SUSPECT SOMETHING INDUCTED INTO PACK INLET CAUSING THE SMOKE.