A B737 parked at the gate and having just under gone hydraulic system maintenance developed a heavy ...

Narrative:

Aircraft evacuated due to smoke; fumes; and mist; from hydraulic system ingested into packs. When we boarded the aircraft; maintenance advised they had drained hydraulic fluid from over serviced reservoirs. Mechanic came up and I made a log book entry as appropriate and mechanic signed it off. The first officer saw major hydraulic fluid on ground during walk around that was being cleaned up and dripping from bottom of hydraulic bay. Mechanics told him they were finishing up. I started APU; turned on right pack; noticed odor; a few minutes later at the same time flight attendant came up; fumes and mist and or smoke intensified. I ordered flight attendant; immediate passenger evacuate through main cabin door; belongings left behind. APU shut down immediately; advised company; maintenance via radio; and called the duty manager desk. Arff was called and at gate within minutes. Maintenance arrived; mist and fumes on flight deck intensified. All passengers and crew evacuated into terminal; no injuries. Logbook entry made. Arff did check with crew; and all passengers had no complaints or issues. First officer and I had irritated eyes and burning nose sensation. We told arff same; he said it should dissipate. That did stay with us until end of trip. No company medical clinic at this airport or in main terminal as told to me by the duty manager. Flight attendants did an excellent job with quick evacuation!! We did continue trip 3 hours later with same crew; different aircraft.

Original NASA ASRS Text

Title: A B737 parked at the gate and having just under gone Hydraulic System Maintenance developed a heavy air conditioning mist and odor from hydraulic fluid ingested in the right pack so the Captain ordered an evacuation into the terminal.

Narrative: Aircraft evacuated due to smoke; fumes; and mist; from hydraulic system ingested into packs. When we boarded the aircraft; Maintenance advised they had drained hydraulic fluid from over serviced reservoirs. Mechanic came up and I made a log book entry as appropriate and Mechanic signed it off. The First Officer saw major hydraulic fluid on ground during walk around that was being cleaned up and dripping from bottom of hydraulic bay. Mechanics told him they were finishing up. I started APU; turned on right pack; noticed odor; a few minutes later at the same time Flight Attendant came up; fumes and mist and or smoke intensified. I ordered Flight Attendant; immediate passenger evacuate through main cabin door; belongings left behind. APU shut down immediately; advised Company; Maintenance via radio; and called the Duty Manager desk. ARFF was called and at gate within minutes. Maintenance arrived; mist and fumes on flight deck intensified. All passengers and crew evacuated into terminal; no injuries. Logbook entry made. ARFF did check with crew; and all passengers had no complaints or issues. First Officer and I had irritated eyes and burning nose sensation. We told ARFF same; he said it should dissipate. That did stay with us until end of trip. No Company medical clinic at this airport or in main terminal as told to me by the Duty Manager. Flight attendants did an EXCELLENT job with quick evacuation!! We did continue trip 3 hours later with same crew; different aircraft.

Data retrieved from NASA's ASRS site as of July 2013 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	1110628
Time
Date	201308
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	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Component
Aircraft Component	Hydraulic System
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 21975 Flight Crew Type 7000
Events
Anomaly	Aircraft Equipment Problem Critical Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor Ground Event / Encounter Other / Unknown

A B737 parked at the gate and having just under gone hydraulic system maintenance developed a heavy air conditioning mist and odor from hydraulic fluid ingested in the right pack so the captain ordered an evacuation into the terminal.