Md-80 captain reported smoke in the aircraft when packs were turned on after pushback. Flight return...

Attributes
ACN	1294562
Time
Date	201509
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Component
Aircraft Component	Hydraulic Main System
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

Narrative:

After pushback and engine start; upon turning air conditioning packs on; acrid smoke began coming out of vents. Shut off packs and recirculating fan while simultaneously returning to gate. Once the packs were turned off the smoke stopped increasing. Deplaned normally without incident. Smoke appears to have come from a loss of the left hydraulic system.

Original NASA ASRS Text

Title: MD-80 Captain reported smoke in the aircraft when packs were turned on after pushback. Flight returned to the gate.

Narrative: After pushback and engine start; upon turning air conditioning packs on; acrid smoke began coming out of vents. Shut off packs and recirculating fan while simultaneously returning to gate. Once the packs were turned off the smoke stopped increasing. Deplaned normally without incident. Smoke appears to have come from a loss of the left hydraulic system.

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.

Md-80 captain reported smoke in the aircraft when packs were turned on after pushback. Flight returned to the gate.