B737 first officer deploys passenger oxygen masks during preflight.

Attributes
ACN	436810
Time
Date	199905
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : parked ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Experience	flight time type : 80
ASRS Report	436810
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	aircraft equipment other aircraft equipment : psgr oxygen sys
Resolutory Action	none taken : detected after the fact
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance

Narrative:

Inadvertently deployed passenger oxygen masks while conducting origination preflight. Threw wrong switch for flight recorder test. Flight recorder test and oxygen mask switches are identical and adjacent black covered switches. Contributing factors were short layover following a long day in the saddle, arrived at aircraft fully boarded and waiting for kickoff to lax. I felt rushed and stupidly acted beyond my experience level for an 80 hour in type first officer. I feel certain this would not have happened if the passenger oxygen switch cover had been safety wired, or I had just taken my time as per normal operations.

Original NASA ASRS Text

Title: B737 FO DEPLOYS PAX OXYGEN MASKS DURING PREFLT.

Narrative: INADVERTENTLY DEPLOYED PAX OXYGEN MASKS WHILE CONDUCTING ORIGINATION PREFLT. THREW WRONG SWITCH FOR FLT RECORDER TEST. FLT RECORDER TEST AND OXYGEN MASK SWITCHES ARE IDENTICAL AND ADJACENT BLACK COVERED SWITCHES. CONTRIBUTING FACTORS WERE SHORT LAYOVER FOLLOWING A LONG DAY IN THE SADDLE, ARRIVED AT ACFT FULLY BOARDED AND WAITING FOR KICKOFF TO LAX. I FELT RUSHED AND STUPIDLY ACTED BEYOND MY EXPERIENCE LEVEL FOR AN 80 HR IN TYPE FO. I FEEL CERTAIN THIS WOULD NOT HAVE HAPPENED IF THE PAX OXYGEN SWITCH COVER HAD BEEN SAFETY WIRED, OR I HAD JUST TAKEN MY TIME AS PER NORMAL OPS.

Data retrieved from NASA's ASRS site as of July 2007 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.