Narrative:

Flying IFR from white plains, ny, to atlanta, GA. When 20 mi west of winchester, va, ZDC noted that my transponder signal was lost. At the same time my LORAN went blank. Checked ammeter and saw that it was discharging. Also, low voltage warning was flashing. Shut down most unnecessary electrical equipment, including pitot heat (big drain) which was on because a few mins earlier I had been in and out of cloud tops at 8000 ft, notified controller of problem and requested vector to nearest airport, also WX. Was given vector of 090 to winchester, va, and WX at dulles (good VFR). Told controller I had hand-held radio in plane and was turning toward winchester. Requested and was given clearance down to 6000 ft. Then radio went dead. Descended to 6000 through hole in broken layer. Was then in good VFR. Continued descent and began looking for winchester. Got out hand-held radio but had an antenna problem with radio. Decided better to concentrate on flying the plane and leave the radio alone. Found winchester and landed without incident. After landing, spoke by telephone with FAA ARTCC area manager, dulles. Problem turned out to be alternator failure, as expected given the symptoms. What to do better? 1) more frequent scan of the ammeter and warning panel to catch problem earlier. 2) some practice with the hand-held radio to be more comfortable with it in an emergency. Other than that, I think I handled the situation properly.

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Original NASA ASRS Text

Title: DURING AN IFR XCOUNTRY, PVT PLT IN AN SMA ACFT EXPERIENCED ACFT ELECTRICAL PROBLEM CAUSING LOSS OF THE PRIMARY NAV AND COM RADIO EQUIP. THE PLT MADE AN UNSCHEDULED LNDG AT A NEAR BY VFR ARPT.

Narrative: FLYING IFR FROM WHITE PLAINS, NY, TO ATLANTA, GA. WHEN 20 MI W OF WINCHESTER, VA, ZDC NOTED THAT MY TRANSPONDER SIGNAL WAS LOST. AT THE SAME TIME MY LORAN WENT BLANK. CHKED AMMETER AND SAW THAT IT WAS DISCHARGING. ALSO, LOW VOLTAGE WARNING WAS FLASHING. SHUT DOWN MOST UNNECESSARY ELECTRICAL EQUIP, INCLUDING PITOT HEAT (BIG DRAIN) WHICH WAS ON BECAUSE A FEW MINS EARLIER I HAD BEEN IN AND OUT OF CLOUD TOPS AT 8000 FT, NOTIFIED CTLR OF PROBLEM AND REQUESTED VECTOR TO NEAREST ARPT, ALSO WX. WAS GIVEN VECTOR OF 090 TO WINCHESTER, VA, AND WX AT DULLES (GOOD VFR). TOLD CTLR I HAD HAND-HELD RADIO IN PLANE AND WAS TURNING TOWARD WINCHESTER. REQUESTED AND WAS GIVEN CLRNC DOWN TO 6000 FT. THEN RADIO WENT DEAD. DSNDED TO 6000 THROUGH HOLE IN BROKEN LAYER. WAS THEN IN GOOD VFR. CONTINUED DSCNT AND BEGAN LOOKING FOR WINCHESTER. GOT OUT HAND-HELD RADIO BUT HAD AN ANTENNA PROBLEM WITH RADIO. DECIDED BETTER TO CONCENTRATE ON FLYING THE PLANE AND LEAVE THE RADIO ALONE. FOUND WINCHESTER AND LANDED WITHOUT INCIDENT. AFTER LNDG, SPOKE BY TELEPHONE WITH FAA ARTCC AREA MGR, DULLES. PROBLEM TURNED OUT TO BE ALTERNATOR FAILURE, AS EXPECTED GIVEN THE SYMPTOMS. WHAT TO DO BETTER? 1) MORE FREQUENT SCAN OF THE AMMETER AND WARNING PANEL TO CATCH PROBLEM EARLIER. 2) SOME PRACTICE WITH THE HAND-HELD RADIO TO BE MORE COMFORTABLE WITH IT IN AN EMER. OTHER THAN THAT, I THINK I HANDLED THE SITUATION PROPERLY.

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.