Captain reported malfunction of the APU at the gate resulting in smoke throughout the aircraft. Cras...

Narrative:

During preflight a single pop sound was noted along with a noticeable change in the sound of airflow in the flight deck. Very shortly afterward smoke was observed entering the flight deck from the air vents. The packs were selected off and after a short period of time smoke was still observed entering the flight deck. The recirculation fans were then selected off.the odor of the smoke did not appear to be an acrid electrical smell. The smoke did not diminish and the packs were reselected on. When the packs were reselected on; the level of smoke intensified. The packs were immediately selected off and all personnel were advised to immediately exit the airplane. Crash fire resource (crash fire rescue equipment) was notified and the aircraft was completely depowered.crash fire rescue equipment arrived at the aircraft and began the process of finding the source of smoke in the cabin. The onboard mechanics sourced steps and opened the APU access doors as the APU was suspected to be the source of the smoke. When the APU access doors were opened; large volumes of smoke poured out of the APU compartment. Crash fire rescue equipment examined the APU compartment for evidence of fire and no fire was noted. The aircraft cabin doors were opened to vent the smoke in the cabin. Crash fire rescue equipment released the plane back to the crew.

Original NASA ASRS Text

Title: Captain reported malfunction of the APU at the gate resulting in smoke throughout the aircraft. Crash Fire Rescue (CFR) was called while personnel left the aircraft. APU was shut down.

Narrative: During preflight a single pop sound was noted along with a noticeable change in the sound of airflow in the flight deck. Very shortly afterward smoke was observed entering the flight deck from the air vents. The packs were selected off and after a short period of time smoke was still observed entering the flight deck. The recirculation fans were then selected off.The odor of the smoke did not appear to be an acrid electrical smell. The smoke did not diminish and the packs were reselected on. When the packs were reselected on; the level of smoke intensified. The packs were immediately selected off and all personnel were advised to immediately exit the airplane. Crash Fire Resource (CFR) was notified and the aircraft was completely depowered.CFR arrived at the aircraft and began the process of finding the source of smoke in the cabin. The onboard mechanics sourced steps and opened the APU access doors as the APU was suspected to be the source of the smoke. When the APU access doors were opened; large volumes of smoke poured out of the APU compartment. CFR examined the APU compartment for evidence of fire and no fire was noted. The aircraft cabin doors were opened to vent the smoke in the cabin. CFR released the plane back to the crew.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1347366
Time
Date	201604
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	Parked
Flight Plan	IFR
Component
Aircraft Component	APU
Person 1
Function	Captain Check Pilot
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

Captain reported malfunction of the APU at the gate resulting in smoke throughout the aircraft. Crash fire rescue (crash fire rescue equipment) was called while personnel left the aircraft. APU was shut down.