What was found
SHORTLY AFTER STARTING THE APU AND SELECTING BLEED ON, A GRAYISH SMOKE COULD BE SMELLED AND SEEN THROUGHOUT THE CABIN AND COCKPIT. SMOKE DISSIPATED AFTER APU SHUT DOWN.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
SHORTLY AFTER STARTING THE APU AND SELECTING BLEED ON, A GRAYISH SMOKE COULD BE SMELLED AND SEEN THROUGHOUT THE CABIN AND COCKPIT. SMOKE DISSIPATED AFTER APU SHUT DOWN.