Narrative:

Electrical failure. First lost gas gauges, then in order: transponder, audio panel, communication #1 and communication #2, GPS, cabin lighting, VOR heads. Advised ATC of difficulty after loss of gas gauges and transponder. Advised ATC of portable communication on board if necessary. When lost all electrical, attempted to contact ATC without success on hand held radio. Successfully landed without any damage at mgj. Contacted FSS to relay message to ATC that landing was successful along with request to close flight plan. Contacted local FBO the next morning at mgj to diagnose problem with electrical. FBO discovered alternator cable was completely detached (alternator is located in area which is not accessible in a C172N). FBO repaired cable and flight continued successfully the next morning to home base. The next day, I discovered when reviewing logbook that I had miscalculated night currency and was out of currency by 3 weeks. (I had my wife on board as my passenger.) I plan on completing 3 night lndgs to a full stop before I take any passenger in the future. As to electrical failure, there is nothing that I could have done to prevent this occurrence. In fact, aircraft had just received its annual within the past month or so.

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Original NASA ASRS Text

Title: EMER LNDG AT ANOTHER ARPT MADE WHEN A C172 PVT PLT LOSES ALL ELECTRICAL DURING A NIGHT OP ON FREQ WITH ZNY, NY.

Narrative: ELECTRICAL FAILURE. FIRST LOST GAS GAUGES, THEN IN ORDER: XPONDER, AUDIO PANEL, COM #1 AND COM #2, GPS, CABIN LIGHTING, VOR HEADS. ADVISED ATC OF DIFFICULTY AFTER LOSS OF GAS GAUGES AND XPONDER. ADVISED ATC OF PORTABLE COM ON BOARD IF NECESSARY. WHEN LOST ALL ELECTRICAL, ATTEMPTED TO CONTACT ATC WITHOUT SUCCESS ON HAND HELD RADIO. SUCCESSFULLY LANDED WITHOUT ANY DAMAGE AT MGJ. CONTACTED FSS TO RELAY MESSAGE TO ATC THAT LNDG WAS SUCCESSFUL ALONG WITH REQUEST TO CLOSE FLT PLAN. CONTACTED LCL FBO THE NEXT MORNING AT MGJ TO DIAGNOSE PROB WITH ELECTRICAL. FBO DISCOVERED ALTERNATOR CABLE WAS COMPLETELY DETACHED (ALTERNATOR IS LOCATED IN AREA WHICH IS NOT ACCESSIBLE IN A C172N). FBO REPAIRED CABLE AND FLT CONTINUED SUCCESSFULLY THE NEXT MORNING TO HOME BASE. THE NEXT DAY, I DISCOVERED WHEN REVIEWING LOGBOOK THAT I HAD MISCALCULATED NIGHT CURRENCY AND WAS OUT OF CURRENCY BY 3 WKS. (I HAD MY WIFE ON BOARD AS MY PAX.) I PLAN ON COMPLETING 3 NIGHT LNDGS TO A FULL STOP BEFORE I TAKE ANY PAX IN THE FUTURE. AS TO ELECTRICAL FAILURE, THERE IS NOTHING THAT I COULD HAVE DONE TO PREVENT THIS OCCURRENCE. IN FACT, ACFT HAD JUST RECEIVED ITS ANNUAL WITHIN THE PAST MONTH OR SO.

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.