Narrative:

While cruising at FL430 we experienced a #1 inverter failure. Because we were flying into the sun, we did not immediately see the inverter fail light. The #1 inverter controls, among other things, the pilot's flight instruments and primary pressurization. We were dealing with the pressure problem by donning our oxygen masks and starting a descent after so advising ATC. ATC told us not to descend because there was traffic immediately behind us at FL410. I tried to prevent the captain from descending immediately but was unsuccessful and ATC diverted the other aircraft. While all of this was going on, my oxygen mask microphone would not function and I had to remove my mask on several occasions to talk into a hand microphone. This, of course, resulted in my becoming quite hypoxic. As a result, I was virtually useless as a copilot during this phase of flight. At approximately FL350, ATC asked if we wanted to declare an emergency and we replied in the affirmative. ATC then diverted us to fresno since it was the closest airport. By the time we were down to 14000 ft, I had turned on the standby inverter and had recovered the use of the pilot's instruments and primary pressurization. The primary cause of the problem was the failure to identify the cause of the problems facing us as being an inverter failure and the failure to use appropriate checklists caused by hypoxia. The best solution to this problem would be an ongoing training program to keep these procedures fresh in our mind in addition to a once a yr trip through flight simulator training.

Related reports:

Google
 

Original NASA ASRS Text

Title: CORP JET HAS INVERTER FAILURE LIGHT ACTIVATE. THIS CTLS PRIMARY FLT INSTS AND PRESSURIZATION. EMER DSCNT.

Narrative: WHILE CRUISING AT FL430 WE EXPERIENCED A #1 INVERTER FAILURE. BECAUSE WE WERE FLYING INTO THE SUN, WE DID NOT IMMEDIATELY SEE THE INVERTER FAIL LIGHT. THE #1 INVERTER CTLS, AMONG OTHER THINGS, THE PLT'S FLT INSTS AND PRIMARY PRESSURIZATION. WE WERE DEALING WITH THE PRESSURE PROB BY DONNING OUR OXYGEN MASKS AND STARTING A DSCNT AFTER SO ADVISING ATC. ATC TOLD US NOT TO DSND BECAUSE THERE WAS TFC IMMEDIATELY BEHIND US AT FL410. I TRIED TO PREVENT THE CAPT FROM DSNDING IMMEDIATELY BUT WAS UNSUCCESSFUL AND ATC DIVERTED THE OTHER ACFT. WHILE ALL OF THIS WAS GOING ON, MY OXYGEN MASK MIKE WOULD NOT FUNCTION AND I HAD TO REMOVE MY MASK ON SEVERAL OCCASIONS TO TALK INTO A HAND MIKE. THIS, OF COURSE, RESULTED IN MY BECOMING QUITE HYPOXIC. AS A RESULT, I WAS VIRTUALLY USELESS AS A COPLT DURING THIS PHASE OF FLT. AT APPROX FL350, ATC ASKED IF WE WANTED TO DECLARE AN EMER AND WE REPLIED IN THE AFFIRMATIVE. ATC THEN DIVERTED US TO FRESNO SINCE IT WAS THE CLOSEST ARPT. BY THE TIME WE WERE DOWN TO 14000 FT, I HAD TURNED ON THE STANDBY INVERTER AND HAD RECOVERED THE USE OF THE PLT'S INSTS AND PRIMARY PRESSURIZATION. THE PRIMARY CAUSE OF THE PROB WAS THE FAILURE TO IDENT THE CAUSE OF THE PROBS FACING US AS BEING AN INVERTER FAILURE AND THE FAILURE TO USE APPROPRIATE CHKLISTS CAUSED BY HYPOXIA. THE BEST SOLUTION TO THIS PROB WOULD BE AN ONGOING TRAINING PROGRAM TO KEEP THESE PROCS FRESH IN OUR MIND IN ADDITION TO A ONCE A YR TRIP THROUGH FLT SIMULATOR TRAINING.

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.