Narrative:

A primary student and I departed on a night cross country flight from pao to lsn late one night. I had never flown in this particular aircraft at night before. During the run-up, the ammeter was checked and showed a positive charge rate. The brightness control for the panel lights appeared to be a little flaky and required some manipulation to achieve maximum brightness. We opened our VFR flight plan and received flight following from norcal approach once airborne. The cross country was uneventful until about 20 mins into the flight. I noticed the panel lights begin to dim and assumed the dimmer control was continuing to be flaky. I increased the light intensity without problem. The low voltage light, which indicates alternator failure, was not illuminated. However, the ammeter is in the far left corner of the panel and is not lit by panel lights, making it difficult to scan. A few mins later, as we were beginning our descent for lsn, the panel lights began to dim further and the radios began to FLIP on and off. I realized that we were about to lose electrical power and tried to contact norcal approach to notify them. I called 'norcal approach, cessna xxxxx' and they replied '(garbled) airport 12 O'clock position, 10 mi, radar services terminated, squawk VFR, change to advisory approved.' assuming the call was for us, they must have believed we were canceling flight following. I tried to call norcal a second time to say we were losing radio contact, but the radios died immediately. I changed the transponder to 7600 in the hopes that at least 1 radar hit would occur before the transponder died completely. I then reduced power consumption by turning off all avionics and interior lights and leaving minimal exterior lights on. Because we were almost at our destination airport, I used my handheld transceiver to try to turn on the pilot controled lighting. The lights did not come on. I tried to contact ATC on the last used frequency without success. I tried to contact FSS without success. All of the other uncontrolled airports in the area have pilot controled lighting. Based on this, I made the decision to return to pao, where I knew the lights were on all night long. I also knew from experience that there was unlikely to be any traffic at pao this late on a week night. Our VFR flight plan was about to expire and I was concerned about search and rescue operations being initiated, so I used my cell phone to contact rancho murieta FSS. The engine noise made it extremely difficult to communicate. I told the briefer that we were canceling our flight plan, that we had an electrical failure, and that we were going to return to pao. I requested that he call pao tower to let them know we were coming even though the tower would close before we arrived. He asked if we needed any assistance and I said 'no.' we then hung up. Our return to pao was uneventful. About 15 mi away, I tuned in the pao tower/CTAF on my handheld and was surprised to hear a tower controller on the air because the tower was supposed to be closed. I called to report our position and condition. He acknowledged and said 'do you know the entire fire department is here waiting for you?' I was quite surprised and told him that we did not need emergency services and to cancel the equipment. The tower controller said he had been driving away from the closed tower when he saw the fire trucks approaching, and returned to reopen the tower. On the ground I was given a phone number to call for the norcal approach supervisor. I called him and explained what we had done and said that I didn't understand why the emergency services had been called. Apparently the FSS briefer had called in a report of a plane crash. No one else had been notified (including the airport manager or tower controller). In retrospect, there are a few things that I could have done differently that may have resulted in a better outcome. I could have reduced the engine power to idle to make phone conversation easier, and had a longer and more thorough conversation with FSS. I could have asked for the phone number of norcal approach and called them in the air to tell them what was going on and to request permission to return to pao (which lies under the sfo modec veil). I also could have tried to contact other airplanes in the area on ATC frequencys or 121.5 to have messages relayed. Finally, I've learned to pay attention to dimming lights and to always include the ammeter in the instrument scan.

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Original NASA ASRS Text

Title: A C172 CFI RPTED THAT HE AND HIS STUDENT RETURNED TO PAO AFTER EXPERIENCING A TOTAL ELECTRICAL FAILURE DURING A XCOUNTRY FLT NEAR THEIR DEST, LSN.

Narrative: A PRIMARY STUDENT AND I DEPARTED ON A NIGHT XCOUNTRY FLT FROM PAO TO LSN LATE ONE NIGHT. I HAD NEVER FLOWN IN THIS PARTICULAR ACFT AT NIGHT BEFORE. DURING THE RUN-UP, THE AMMETER WAS CHKED AND SHOWED A POSITIVE CHARGE RATE. THE BRIGHTNESS CTL FOR THE PANEL LIGHTS APPEARED TO BE A LITTLE FLAKY AND REQUIRED SOME MANIPULATION TO ACHIEVE MAX BRIGHTNESS. WE OPENED OUR VFR FLT PLAN AND RECEIVED FLT FOLLOWING FROM NORCAL APCH ONCE AIRBORNE. THE XCOUNTRY WAS UNEVENTFUL UNTIL ABOUT 20 MINS INTO THE FLT. I NOTICED THE PANEL LIGHTS BEGIN TO DIM AND ASSUMED THE DIMMER CTL WAS CONTINUING TO BE FLAKY. I INCREASED THE LIGHT INTENSITY WITHOUT PROB. THE LOW VOLTAGE LIGHT, WHICH INDICATES ALTERNATOR FAILURE, WAS NOT ILLUMINATED. HOWEVER, THE AMMETER IS IN THE FAR L CORNER OF THE PANEL AND IS NOT LIT BY PANEL LIGHTS, MAKING IT DIFFICULT TO SCAN. A FEW MINS LATER, AS WE WERE BEGINNING OUR DSCNT FOR LSN, THE PANEL LIGHTS BEGAN TO DIM FURTHER AND THE RADIOS BEGAN TO FLIP ON AND OFF. I REALIZED THAT WE WERE ABOUT TO LOSE ELECTRICAL PWR AND TRIED TO CONTACT NORCAL APCH TO NOTIFY THEM. I CALLED 'NORCAL APCH, CESSNA XXXXX' AND THEY REPLIED '(GARBLED) ARPT 12 O'CLOCK POS, 10 MI, RADAR SVCS TERMINATED, SQUAWK VFR, CHANGE TO ADVISORY APPROVED.' ASSUMING THE CALL WAS FOR US, THEY MUST HAVE BELIEVED WE WERE CANCELING FLT FOLLOWING. I TRIED TO CALL NORCAL A SECOND TIME TO SAY WE WERE LOSING RADIO CONTACT, BUT THE RADIOS DIED IMMEDIATELY. I CHANGED THE XPONDER TO 7600 IN THE HOPES THAT AT LEAST 1 RADAR HIT WOULD OCCUR BEFORE THE XPONDER DIED COMPLETELY. I THEN REDUCED PWR CONSUMPTION BY TURNING OFF ALL AVIONICS AND INTERIOR LIGHTS AND LEAVING MINIMAL EXTERIOR LIGHTS ON. BECAUSE WE WERE ALMOST AT OUR DEST ARPT, I USED MY HANDHELD TRANSCEIVER TO TRY TO TURN ON THE PLT CTLED LIGHTING. THE LIGHTS DID NOT COME ON. I TRIED TO CONTACT ATC ON THE LAST USED FREQ WITHOUT SUCCESS. I TRIED TO CONTACT FSS WITHOUT SUCCESS. ALL OF THE OTHER UNCTLED ARPTS IN THE AREA HAVE PLT CTLED LIGHTING. BASED ON THIS, I MADE THE DECISION TO RETURN TO PAO, WHERE I KNEW THE LIGHTS WERE ON ALL NIGHT LONG. I ALSO KNEW FROM EXPERIENCE THAT THERE WAS UNLIKELY TO BE ANY TFC AT PAO THIS LATE ON A WK NIGHT. OUR VFR FLT PLAN WAS ABOUT TO EXPIRE AND I WAS CONCERNED ABOUT SEARCH AND RESCUE OPS BEING INITIATED, SO I USED MY CELL PHONE TO CONTACT RANCHO MURIETA FSS. THE ENG NOISE MADE IT EXTREMELY DIFFICULT TO COMMUNICATE. I TOLD THE BRIEFER THAT WE WERE CANCELING OUR FLT PLAN, THAT WE HAD AN ELECTRICAL FAILURE, AND THAT WE WERE GOING TO RETURN TO PAO. I REQUESTED THAT HE CALL PAO TWR TO LET THEM KNOW WE WERE COMING EVEN THOUGH THE TWR WOULD CLOSE BEFORE WE ARRIVED. HE ASKED IF WE NEEDED ANY ASSISTANCE AND I SAID 'NO.' WE THEN HUNG UP. OUR RETURN TO PAO WAS UNEVENTFUL. ABOUT 15 MI AWAY, I TUNED IN THE PAO TWR/CTAF ON MY HANDHELD AND WAS SURPRISED TO HEAR A TWR CTLR ON THE AIR BECAUSE THE TWR WAS SUPPOSED TO BE CLOSED. I CALLED TO RPT OUR POS AND CONDITION. HE ACKNOWLEDGED AND SAID 'DO YOU KNOW THE ENTIRE FIRE DEPT IS HERE WAITING FOR YOU?' I WAS QUITE SURPRISED AND TOLD HIM THAT WE DID NOT NEED EMER SVCS AND TO CANCEL THE EQUIP. THE TWR CTLR SAID HE HAD BEEN DRIVING AWAY FROM THE CLOSED TWR WHEN HE SAW THE FIRE TRUCKS APCHING, AND RETURNED TO REOPEN THE TWR. ON THE GND I WAS GIVEN A PHONE NUMBER TO CALL FOR THE NORCAL APCH SUPVR. I CALLED HIM AND EXPLAINED WHAT WE HAD DONE AND SAID THAT I DIDN'T UNDERSTAND WHY THE EMER SVCS HAD BEEN CALLED. APPARENTLY THE FSS BRIEFER HAD CALLED IN A RPT OF A PLANE CRASH. NO ONE ELSE HAD BEEN NOTIFIED (INCLUDING THE ARPT MGR OR TWR CTLR). IN RETROSPECT, THERE ARE A FEW THINGS THAT I COULD HAVE DONE DIFFERENTLY THAT MAY HAVE RESULTED IN A BETTER OUTCOME. I COULD HAVE REDUCED THE ENG PWR TO IDLE TO MAKE PHONE CONVERSATION EASIER, AND HAD A LONGER AND MORE THOROUGH CONVERSATION WITH FSS. I COULD HAVE ASKED FOR THE PHONE NUMBER OF NORCAL APCH AND CALLED THEM IN THE AIR TO TELL THEM WHAT WAS GOING ON AND TO REQUEST PERMISSION TO RETURN TO PAO (WHICH LIES UNDER THE SFO MODEC VEIL). I ALSO COULD HAVE TRIED TO CONTACT OTHER AIRPLANES IN THE AREA ON ATC FREQS OR 121.5 TO HAVE MESSAGES RELAYED. FINALLY, I'VE LEARNED TO PAY ATTN TO DIMMING LIGHTS AND TO ALWAYS INCLUDE THE AMMETER IN THE INST SCAN.

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.