IFR pilot cleared to 13000 ft but no oxygen on board. Failed to monitor time at altitude.

Attributes
ACN	225815
Time
Date	199211
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : fbr
State Reference	WY
Altitude	msl bound lower : 13000 msl bound upper : 13000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	artcc : zlc
Operator	general aviation : instructional
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : cfi pilot : instrument
Experience	flight time last 90 days : 120 flight time total : 430 flight time type : 60
ASRS Report	225815
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was flying level at 12000 ft MSL en route to salt lake city. ATC changed our altitude to 13000 ft MSL. The problem was that I forgot to keep track of how long we were above 12500 ft, as we did not have oxygen on board. I don't believe we were above 12500 ft for more than 30 mins, but I'm not sure. We later were cleared back to 12000 ft.

Original NASA ASRS Text

Title: IFR PLT CLRED TO 13000 FT BUT NO OXYGEN ON BOARD. FAILED TO MONITOR TIME AT ALT.

Narrative: I WAS FLYING LEVEL AT 12000 FT MSL ENRTE TO SALT LAKE CITY. ATC CHANGED OUR ALT TO 13000 FT MSL. THE PROBLEM WAS THAT I FORGOT TO KEEP TRACK OF HOW LONG WE WERE ABOVE 12500 FT, AS WE DID NOT HAVE OXYGEN ON BOARD. I DON'T BELIEVE WE WERE ABOVE 12500 FT FOR MORE THAN 30 MINS, BUT I'M NOT SURE. WE LATER WERE CLRED BACK TO 12000 FT.

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.