B757-200
Flight Crew Air Transport Pilot (ATP)
Physiological - Other; Situational Awareness; Troubleshooting
Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Ground Event / Encounter Other / Unknown
Flight Crew Took Evasive Action; General Evacuated; General Declared Emergency; General Maintenance Action
Human Factors; Company Policy; Procedure; Weather
With APU running and in the blocks at gate preparing for pushback; cockpit filled up with heavy; acrid smoke.  Turned off packs and closed bleed valves; smoke slowly dissipated. Smoke emanated from the vent areas on the lower left side of the flight deck.  First Officer got up and opened L1 door; stairs were in place.  Contacted ramp tower; who notified fire department; and then we contacted maintenance.  Conferred with both maintenance and fire crew; wrote up discrepancy.Possible de-icing of the tail area without notification to flight crew.  When leaving the aircraft; noticed de-ice fluid on the ground.  There was also snow in the courier area and main cargo deck upon arrival at the aircraft.  Called maintenance; who removed the snow and water; but moisture may have gotten into certain systems.
Preflight Normal. Called maintenance for snow removal. Closed the door and ready for push back. Called for Beacon and Engine Inlet Inspection. While waiting for approx 1 hour (total time from jet arrival) with Packs running noticed Heavy smoke out of vents on left side of cockpit. Shut down Packs Bleeds and APU; then notified Ramp tower. Smoke dissipated as we waited in courier area with door open; Fire Department and Maintenance could find no evidence of heat although smoke appeared when maintenance tried to duplicate. After exiting the aircraft we noticed some evidence of de-icing at the back of aircraft. It is possible Deicing commenced without our knowledge. No one contacted us on the radio or intercom.It is possible the aircraft was deiced without communicating with crew.
A B757-200 filled with smoke while at the gate with the APU running. The smoke dissipated with the packs off and bleeds closed. Apparently the de-ice crew allowed fluid to enter the APU intake.