Narrative:

Departing teterboro (local ceiling approximately 3000') in an small transport carrying cancelled checks and miscellaneous cargo for buffalo, ny. I was cleared up to 9000' by new york departure control and around 8000' noticed the red 'low volt' light was on. It was dimmed quite low from previous flts, and this contributed to the lengthy time taken to notice electrical problem. Also the words 'low volt' themselves are not illuminated so I had to use flashlight to determine meaning of the light as I was not familiar. I then checked the amber 'alternator inoperative' lights and noticed the left one indicated an alternator failure. I checked the ammeter and it indicated there was no output on the left alternator. The right alternator inoperative light appeared off, and the ammeter reading for the right alternator appeared low, but not zero. It usually appears lower than the right alternator, so I thought this was normal. I then thought the left alternator only had failed, and pulled the checklist and performed the 'one alternator inoperative' checklist. This did not restore the left alternator, and by now about 5 minutes after noticing 'low volt' light). The cabin lights were dim and the radios were failing. I did not understand why one alternator failure could cause a total electrical failure, unless there was some sort of system failure, which I had to assume, for lack of a better reason. I attempted to declare an emergency on the radio (on 127.6 ny departure) but the voltage was too low and I put 7700 in the transponder, although I doubted it would work either. Now I had to decide what to do. It was IFR all the way to buffalo and we had no power, for communication radios or navigation radios and only a flashlight bulb to see by (by now there was no light at all from the aircraft). I know the procedures for radio failure in IFR is to continue to destination but this assumes the navigation radios are working and mine were not. I knew where I was at the time (approximately) and that the bases of the clouds were 2000-2500' AGL. I had no way of navigating and I knew the WX got lower the further we flew (and the ground got higher) so I decided to descend to VFR without an ATC clearance. Leveling off at 2500', in VFR, while starting to look for an airport, I decided it extremely unlikely to have 2 alternator failures in one flight, so I fiddled with the right alternator inoperative light and it too was on, however, it was dimmed so low it could not at first be seen. I didn't believe I could have 2 alternator failures and I then realized I neglected to turn the alternators on at the beginning of the flight. I looked around the control wheel and they were off. I flipped them on and everything was back to normal. I called approach, explained the problem and altitude, then continued on to buffalo.

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Original NASA ASRS Text

Title: PLT OF LIGHT TWIN ENGINE EXPERIENCES LOSS OF ELECTRICAL DUE ALTERNATOR SWITCHES NOT HAVING BEEN TURNED ON.

Narrative: DEPARTING TETERBORO (LOCAL CEILING APPROX 3000') IN AN SMT CARRYING CANCELLED CHECKS AND MISCELLANEOUS CARGO FOR BUFFALO, NY. I WAS CLRED UP TO 9000' BY NEW YORK DEP CTL AND AROUND 8000' NOTICED THE RED 'LOW VOLT' LIGHT WAS ON. IT WAS DIMMED QUITE LOW FROM PREVIOUS FLTS, AND THIS CONTRIBUTED TO THE LENGTHY TIME TAKEN TO NOTICE ELECTRICAL PROBLEM. ALSO THE WORDS 'LOW VOLT' THEMSELVES ARE NOT ILLUMINATED SO I HAD TO USE FLASHLIGHT TO DETERMINE MEANING OF THE LIGHT AS I WAS NOT FAMILIAR. I THEN CHECKED THE AMBER 'ALTERNATOR INOP' LIGHTS AND NOTICED THE LEFT ONE INDICATED AN ALTERNATOR FAILURE. I CHECKED THE AMMETER AND IT INDICATED THERE WAS NO OUTPUT ON THE LEFT ALTERNATOR. THE RIGHT ALTERNATOR INOP LIGHT APPEARED OFF, AND THE AMMETER READING FOR THE RIGHT ALTERNATOR APPEARED LOW, BUT NOT ZERO. IT USUALLY APPEARS LOWER THAN THE RIGHT ALTERNATOR, SO I THOUGHT THIS WAS NORMAL. I THEN THOUGHT THE LEFT ALTERNATOR ONLY HAD FAILED, AND PULLED THE CHECKLIST AND PERFORMED THE 'ONE ALTERNATOR INOP' CHECKLIST. THIS DID NOT RESTORE THE LEFT ALTERNATOR, AND BY NOW ABOUT 5 MINUTES AFTER NOTICING 'LOW VOLT' LIGHT). THE CABIN LIGHTS WERE DIM AND THE RADIOS WERE FAILING. I DID NOT UNDERSTAND WHY ONE ALTERNATOR FAILURE COULD CAUSE A TOTAL ELECTRICAL FAILURE, UNLESS THERE WAS SOME SORT OF SYSTEM FAILURE, WHICH I HAD TO ASSUME, FOR LACK OF A BETTER REASON. I ATTEMPTED TO DECLARE AN EMER ON THE RADIO (ON 127.6 NY DEP) BUT THE VOLTAGE WAS TOO LOW AND I PUT 7700 IN THE XPONDER, ALTHOUGH I DOUBTED IT WOULD WORK EITHER. NOW I HAD TO DECIDE WHAT TO DO. IT WAS IFR ALL THE WAY TO BUFFALO AND WE HAD NO POWER, FOR COM RADIOS OR NAV RADIOS AND ONLY A FLASHLIGHT BULB TO SEE BY (BY NOW THERE WAS NO LIGHT AT ALL FROM THE ACFT). I KNOW THE PROCS FOR RADIO FAILURE IN IFR IS TO CONTINUE TO DEST BUT THIS ASSUMES THE NAV RADIOS ARE WORKING AND MINE WERE NOT. I KNEW WHERE I WAS AT THE TIME (APPROX) AND THAT THE BASES OF THE CLOUDS WERE 2000-2500' AGL. I HAD NO WAY OF NAVIGATING AND I KNEW THE WX GOT LOWER THE FURTHER WE FLEW (AND THE GND GOT HIGHER) SO I DECIDED TO DSND TO VFR WITHOUT AN ATC CLRNC. LEVELING OFF AT 2500', IN VFR, WHILE STARTING TO LOOK FOR AN ARPT, I DECIDED IT EXTREMELY UNLIKELY TO HAVE 2 ALTERNATOR FAILURES IN ONE FLT, SO I FIDDLED WITH THE RIGHT ALTERNATOR INOP LIGHT AND IT TOO WAS ON, HOWEVER, IT WAS DIMMED SO LOW IT COULD NOT AT FIRST BE SEEN. I DIDN'T BELIEVE I COULD HAVE 2 ALTERNATOR FAILURES AND I THEN REALIZED I NEGLECTED TO TURN THE ALTERNATORS ON AT THE BEGINNING OF THE FLT. I LOOKED AROUND THE CTL WHEEL AND THEY WERE OFF. I FLIPPED THEM ON AND EVERYTHING WAS BACK TO NORMAL. I CALLED APCH, EXPLAINED THE PROBLEM AND ALT, THEN CONTINUED ON TO BUFFALO.

Data retrieved from NASA's ASRS site as of August 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.