Medium large transport has 0 crew oxygen indication. Divert land.

Attributes
ACN	289902
Time
Date	199411
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : ktn
State Reference	AK
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zan tower : stl
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 140 flight time total : 5000 flight time type : 800
ASRS Report	289902
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : atp pilot : instrument
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Flight departed sea for anc. We had 2 authority/authorized pilot jumpseat riders from other carriers. Jumpseaters were given appropriate brief and I watched #2 observer seat (jumpseater) turn on the appropriate oxygen (flow supply). En route at FL310, we noticed crew oxygen indicator at 0. We found the emergency switch on at the #2 observer station, which was the reason. We asked anc for descent to 10000 ft and clearance to juneau, where we had maintenance replace crew oxygen, then continued flight to anc.

Original NASA ASRS Text

Title: MLG HAS 0 CREW OXYGEN INDICATION. DIVERT LAND.

Narrative: FLT DEPARTED SEA FOR ANC. WE HAD 2 AUTH PLT JUMPSEAT RIDERS FROM OTHER CARRIERS. JUMPSEATERS WERE GIVEN APPROPRIATE BRIEF AND I WATCHED #2 OBSERVER SEAT (JUMPSEATER) TURN ON THE APPROPRIATE OXYGEN (FLOW SUPPLY). ENRTE AT FL310, WE NOTICED CREW OXYGEN INDICATOR AT 0. WE FOUND THE EMER SWITCH ON AT THE #2 OBSERVER STATION, WHICH WAS THE REASON. WE ASKED ANC FOR DSCNT TO 10000 FT AND CLRNC TO JUNEAU, WHERE WE HAD MAINT REPLACE CREW OXYGEN, THEN CONTINUED FLT TO ANC.

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.