Narrative:

While en route from tampa to ft lauderdale executive airport approximately 30 mins into the flight I noticed the ammeters seemed to be reading low. While at altitude I referenced my poh and followed procedure to change voltage regulators (alternator circuit breaker part of procedure). No change in gauge readout. Thus, I continued the flight thinking perhaps I was creating a problem where no problem existed. In any event, the approximately 1 hour flight was short and all system were functioning properly. Perhaps at this time I could have turned off some radios to reduce electrical draw, but I was unsure there was a problem requiring radio reduction and I was soon to begin a descent for an instrument approach in which all radios were of use. At this time I suppose I could have advised ATC of a potential problem, but all light emitting diode (led) lights within radios appeared normal. After breaking out of clouds at about 1000 ft AGL, I turned on landing lights for dusk and low visibilities -- everything still ok. Upon selection of landing gear the entire panel went black and the radios were inoperative. I shut off the avionics master switch and landing lights, pulled out my handheld radio and advised the tower of electrical power loss. The mechanical indicator showed gear not down so I asked the tower for a visual check. Tower advised gear partially extended so I executed a left turn-out and advised I would circle north of the airport while attempting to manually lower the gear. While circling north I hope I did not encroach into adjoining pompano class D airspace. At the time, it was quite turbulent (many aircraft reported low level wind shear before me on approach) with my 3 yr old daughter throwing up and crying behind me because of the moderate turbulence. I believed I was still on an instrument flight plan but I took the initiative to advise I was to circle north of the field in hopes of resolving the problem quickly. It was quickly becoming dark and I was concerned about my ability to read the instrument panel. I requested another tower fly-by to verify gear down and then made a request to fit into landing sequence as soon as possible because of the dark conditions. I was given a left base entry to runway 8 and landed uneventfully. The following week I was advised by the head of maintenance at the repair facility who checked out the plane postflt that the FAA had phoned wanting to receive an update on the condition of the plane. I was surprised they had phoned and thought perhaps the agency was pursuing an investigation. Until that point, I thought I had done nothing wrong. The 2 mistakes one could argue were not advising ATC of my concerns about electrical problems in advance of failure and perhaps traveling into adjoining class D airspace, which I have no knowledge of doing but list as a possibility.

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Original NASA ASRS Text

Title: PLT OF SMT EXPERIENCES ELECTRICAL PROBS THAT ULTIMATELY LEAD TO A COMPLETE LOSS OF ELECTRICAL PWR.

Narrative: WHILE ENRTE FROM TAMPA TO FT LAUDERDALE EXECUTIVE ARPT APPROX 30 MINS INTO THE FLT I NOTICED THE AMMETERS SEEMED TO BE READING LOW. WHILE AT ALT I REFERENCED MY POH AND FOLLOWED PROC TO CHANGE VOLTAGE REGULATORS (ALTERNATOR CIRCUIT BREAKER PART OF PROC). NO CHANGE IN GAUGE READOUT. THUS, I CONTINUED THE FLT THINKING PERHAPS I WAS CREATING A PROB WHERE NO PROB EXISTED. IN ANY EVENT, THE APPROX 1 HR FLT WAS SHORT AND ALL SYS WERE FUNCTIONING PROPERLY. PERHAPS AT THIS TIME I COULD HAVE TURNED OFF SOME RADIOS TO REDUCE ELECTRICAL DRAW, BUT I WAS UNSURE THERE WAS A PROB REQUIRING RADIO REDUCTION AND I WAS SOON TO BEGIN A DSCNT FOR AN INST APCH IN WHICH ALL RADIOS WERE OF USE. AT THIS TIME I SUPPOSE I COULD HAVE ADVISED ATC OF A POTENTIAL PROB, BUT ALL LIGHT EMITTING DIODE (LED) LIGHTS WITHIN RADIOS APPEARED NORMAL. AFTER BREAKING OUT OF CLOUDS AT ABOUT 1000 FT AGL, I TURNED ON LNDG LIGHTS FOR DUSK AND LOW VISIBILITIES -- EVERYTHING STILL OK. UPON SELECTION OF LNDG GEAR THE ENTIRE PANEL WENT BLACK AND THE RADIOS WERE INOP. I SHUT OFF THE AVIONICS MASTER SWITCH AND LNDG LIGHTS, PULLED OUT MY HANDHELD RADIO AND ADVISED THE TWR OF ELECTRICAL PWR LOSS. THE MECHANICAL INDICATOR SHOWED GEAR NOT DOWN SO I ASKED THE TWR FOR A VISUAL CHK. TWR ADVISED GEAR PARTIALLY EXTENDED SO I EXECUTED A L TURN-OUT AND ADVISED I WOULD CIRCLE N OF THE ARPT WHILE ATTEMPTING TO MANUALLY LOWER THE GEAR. WHILE CIRCLING N I HOPE I DID NOT ENCROACH INTO ADJOINING POMPANO CLASS D AIRSPACE. AT THE TIME, IT WAS QUITE TURBULENT (MANY ACFT RPTED LOW LEVEL WIND SHEAR BEFORE ME ON APCH) WITH MY 3 YR OLD DAUGHTER THROWING UP AND CRYING BEHIND ME BECAUSE OF THE MODERATE TURB. I BELIEVED I WAS STILL ON AN INST FLT PLAN BUT I TOOK THE INITIATIVE TO ADVISE I WAS TO CIRCLE N OF THE FIELD IN HOPES OF RESOLVING THE PROB QUICKLY. IT WAS QUICKLY BECOMING DARK AND I WAS CONCERNED ABOUT MY ABILITY TO READ THE INST PANEL. I REQUESTED ANOTHER TWR FLY-BY TO VERIFY GEAR DOWN AND THEN MADE A REQUEST TO FIT INTO LNDG SEQUENCE ASAP BECAUSE OF THE DARK CONDITIONS. I WAS GIVEN A L BASE ENTRY TO RWY 8 AND LANDED UNEVENTFULLY. THE FOLLOWING WK I WAS ADVISED BY THE HEAD OF MAINT AT THE REPAIR FACILITY WHO CHKED OUT THE PLANE POSTFLT THAT THE FAA HAD PHONED WANTING TO RECEIVE AN UPDATE ON THE CONDITION OF THE PLANE. I WAS SURPRISED THEY HAD PHONED AND THOUGHT PERHAPS THE AGENCY WAS PURSUING AN INVESTIGATION. UNTIL THAT POINT, I THOUGHT I HAD DONE NOTHING WRONG. THE 2 MISTAKES ONE COULD ARGUE WERE NOT ADVISING ATC OF MY CONCERNS ABOUT ELECTRICAL PROBS IN ADVANCE OF FAILURE AND PERHAPS TRAVELING INTO ADJOINING CLASS D AIRSPACE, WHICH I HAVE NO KNOWLEDGE OF DOING BUT LIST AS A POSSIBILITY.

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.