Narrative:

Leaving the ellensburg VOR eastbound by 10 mins or so I noted my #1 VOR was beginning to scallop--not hold course with wide swings from side to side of the needle. I began using the #2 VOR for navigation. At about this same time sea center transferred me to grant county approach. I reached them on my second attempt and was cleared to 4000' from a previous descent clearance by center to 7000'. I noted my #2 VOR was beginning to show similar deviations as the #1 VOR at about 5 mins later. I was also getting an auditory click. I rechked my instruments finally detecting discharge on the ammeter. I checked the breakers and recycled the alternator while also being cleared by approach to 3000'. When I was unable to receive grant county approach, I tuned 7700 on the transponder. After shutting off all lighting, I was able to re-establish communications with grant county approach and was eventually cleared to land on runway 18 at moses lake. There was insufficient electrical power for flaps. Grant county tower assisted in locating an FBO open on a sat. After checking the electrical system, FBO removed the alternator and discovered the upper brush had become dislodged from its holder and was broken. After replacing the brush, the alternator again charged, but again failed during taxi. Eventually the next week a relay was also found to have failed. The alternator failure on an IFR flight had occurred at same time before I discovered the failure leading to loss of most battery reserves. I learned to include the altimeter in my scan much more frequently.

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Original NASA ASRS Text

Title: GA SMA ALTERNATOR FAILURE ENROUTE TO MWH. BATTERY POWER SUFFICIENT FOR RADIO COM BUT NOT ENOUGH POWER TO LOWER WING FLAPS.

Narrative: LEAVING THE ELLENSBURG VOR EBND BY 10 MINS OR SO I NOTED MY #1 VOR WAS BEGINNING TO SCALLOP--NOT HOLD COURSE WITH WIDE SWINGS FROM SIDE TO SIDE OF THE NEEDLE. I BEGAN USING THE #2 VOR FOR NAV. AT ABOUT THIS SAME TIME SEA CENTER TRANSFERRED ME TO GRANT COUNTY APCH. I REACHED THEM ON MY SECOND ATTEMPT AND WAS CLRED TO 4000' FROM A PREVIOUS DSCNT CLRNC BY CENTER TO 7000'. I NOTED MY #2 VOR WAS BEGINNING TO SHOW SIMILAR DEVIATIONS AS THE #1 VOR AT ABOUT 5 MINS LATER. I WAS ALSO GETTING AN AUDITORY CLICK. I RECHKED MY INSTRUMENTS FINALLY DETECTING DISCHARGE ON THE AMMETER. I CHKED THE BREAKERS AND RECYCLED THE ALTERNATOR WHILE ALSO BEING CLRED BY APCH TO 3000'. WHEN I WAS UNABLE TO RECEIVE GRANT COUNTY APCH, I TUNED 7700 ON THE TRANSPONDER. AFTER SHUTTING OFF ALL LIGHTING, I WAS ABLE TO RE-ESTABLISH COMS WITH GRANT COUNTY APCH AND WAS EVENTUALLY CLRED TO LAND ON RWY 18 AT MOSES LAKE. THERE WAS INSUFFICIENT ELECTRICAL PWR FOR FLAPS. GRANT COUNTY TWR ASSISTED IN LOCATING AN FBO OPEN ON A SAT. AFTER CHKING THE ELECTRICAL SYS, FBO REMOVED THE ALTERNATOR AND DISCOVERED THE UPPER BRUSH HAD BECOME DISLODGED FROM ITS HOLDER AND WAS BROKEN. AFTER REPLACING THE BRUSH, THE ALTERNATOR AGAIN CHARGED, BUT AGAIN FAILED DURING TAXI. EVENTUALLY THE NEXT WEEK A RELAY WAS ALSO FOUND TO HAVE FAILED. THE ALTERNATOR FAILURE ON AN IFR FLT HAD OCCURRED AT SAME TIME BEFORE I DISCOVERED THE FAILURE LEADING TO LOSS OF MOST BATTERY RESERVES. I LEARNED TO INCLUDE THE ALTIMETER IN MY SCAN MUCH MORE FREQUENTLY.

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.