Narrative:

I was flying in IMC at 9000 ft leaving the houston area on an IFR flight plan to hot springs, ar. There were heavy thunderstorms ahead to the north, and I was being vectored eastward around them. Rather than remain clear of the activity, I entered an area of rain and extremely strong updraft, which caused me to leave my assigned altitude and climb approximately 2000 ft before the ascent stopped. I immediately tried to contact ZHU for vectors clear of the WX, but there was a slight delay as the controller indicated that he thought he had already 'handed me off' to another controller. I was told to turn 'hard right' and change frequencys, which I did. As soon as I was able, I also began a descent to my assigned altitude. When I established contact with the new controller, it appeared he was having trouble receiving my transponder, at which time I noticed that the 'respond' light on the transponder was not illuminating. Also, my argus moving map had turned off and I immediately began to suspect I had an electrical problem. Soon after, I was unable to reach ATC and could only hear their calls to me. At this point, I put 7600 on the transponder, which was probably ineffective and assessed my situation as being very serious. I felt this was an emergency condition due to loss of communication with ATC, loss of navigation due to electrical failure, and not knowing my current position due to the storm and the subsequent diversion. Fortunately, I saw the clouds thinning below me and began an immediate descent and quickly broke out below the cloud layer. I saw an airfield below me as I broke out, and immediately headed for it to land, as I continued to try to contact ATC. Just as I was passing over the airport, I received a final contact from ATC asking for my altitude. I replied that I was at 1800 ft and did not know my current location, but had an airport below me and was landing immediately. ATC replied that they had a 'primary' target over evadale, tx, which turned out to be my location. Although it turned out that evadale airport had been closed one month ago, I made an uneventful landing. I called FSS on my cell phone and requested that they contact ZHU and advise them that I was on the ground at evadale, which they did. We subsequently determined that the brushes had failed in the generator and stopped charging the battery. All the instruments and radios were otherwise operating properly. As a result of this event, the generator is being replaced by an stc'ed alternator for improved reliability and a low voltage warning light will be added to the instrument panel.

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Original NASA ASRS Text

Title: MOONEY M20 PLT LOST ELECTRICAL PWR DURING IFR FLT RESULTING IN DIVERSION TO ANOTHER ARPT AFTER DSNDING INTO VFR CONDITIONS.

Narrative: I WAS FLYING IN IMC AT 9000 FT LEAVING THE HOUSTON AREA ON AN IFR FLT PLAN TO HOT SPRINGS, AR. THERE WERE HVY TSTMS AHEAD TO THE N, AND I WAS BEING VECTORED EASTWARD AROUND THEM. RATHER THAN REMAIN CLR OF THE ACTIVITY, I ENTERED AN AREA OF RAIN AND EXTREMELY STRONG UPDRAFT, WHICH CAUSED ME TO LEAVE MY ASSIGNED ALT AND CLB APPROX 2000 FT BEFORE THE ASCENT STOPPED. I IMMEDIATELY TRIED TO CONTACT ZHU FOR VECTORS CLR OF THE WX, BUT THERE WAS A SLIGHT DELAY AS THE CTLR INDICATED THAT HE THOUGHT HE HAD ALREADY 'HANDED ME OFF' TO ANOTHER CTLR. I WAS TOLD TO TURN 'HARD R' AND CHANGE FREQS, WHICH I DID. AS SOON AS I WAS ABLE, I ALSO BEGAN A DSCNT TO MY ASSIGNED ALT. WHEN I ESTABLISHED CONTACT WITH THE NEW CTLR, IT APPEARED HE WAS HAVING TROUBLE RECEIVING MY XPONDER, AT WHICH TIME I NOTICED THAT THE 'RESPOND' LIGHT ON THE XPONDER WAS NOT ILLUMINATING. ALSO, MY ARGUS MOVING MAP HAD TURNED OFF AND I IMMEDIATELY BEGAN TO SUSPECT I HAD AN ELECTRICAL PROB. SOON AFTER, I WAS UNABLE TO REACH ATC AND COULD ONLY HEAR THEIR CALLS TO ME. AT THIS POINT, I PUT 7600 ON THE XPONDER, WHICH WAS PROBABLY INEFFECTIVE AND ASSESSED MY SIT AS BEING VERY SERIOUS. I FELT THIS WAS AN EMER CONDITION DUE TO LOSS OF COM WITH ATC, LOSS OF NAV DUE TO ELECTRICAL FAILURE, AND NOT KNOWING MY CURRENT POS DUE TO THE STORM AND THE SUBSEQUENT DIVERSION. FORTUNATELY, I SAW THE CLOUDS THINNING BELOW ME AND BEGAN AN IMMEDIATE DSCNT AND QUICKLY BROKE OUT BELOW THE CLOUD LAYER. I SAW AN AIRFIELD BELOW ME AS I BROKE OUT, AND IMMEDIATELY HEADED FOR IT TO LAND, AS I CONTINUED TO TRY TO CONTACT ATC. JUST AS I WAS PASSING OVER THE ARPT, I RECEIVED A FINAL CONTACT FROM ATC ASKING FOR MY ALT. I REPLIED THAT I WAS AT 1800 FT AND DID NOT KNOW MY CURRENT LOCATION, BUT HAD AN ARPT BELOW ME AND WAS LNDG IMMEDIATELY. ATC REPLIED THAT THEY HAD A 'PRIMARY' TARGET OVER EVADALE, TX, WHICH TURNED OUT TO BE MY LOCATION. ALTHOUGH IT TURNED OUT THAT EVADALE ARPT HAD BEEN CLOSED ONE MONTH AGO, I MADE AN UNEVENTFUL LNDG. I CALLED FSS ON MY CELL PHONE AND REQUESTED THAT THEY CONTACT ZHU AND ADVISE THEM THAT I WAS ON THE GND AT EVADALE, WHICH THEY DID. WE SUBSEQUENTLY DETERMINED THAT THE BRUSHES HAD FAILED IN THE GENERATOR AND STOPPED CHARGING THE BATTERY. ALL THE INSTS AND RADIOS WERE OTHERWISE OPERATING PROPERLY. AS A RESULT OF THIS EVENT, THE GENERATOR IS BEING REPLACED BY AN STC'ED ALTERNATOR FOR IMPROVED RELIABILITY AND A LOW VOLTAGE WARNING LIGHT WILL BE ADDED TO THE INST PANEL.

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.