Small aircraft experiences electrical problems.

Attributes
ACN	152756
Time
Date	199008
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bal airport : bwi
State Reference	MD
Altitude	msl bound lower : 3500 msl bound upper : 3500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bwi
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 79 flight time total : 638 flight time type : 250
ASRS Report	152756
Person 2
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem other
Consequence	faa : reviewed incident with flight crew Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Departed cge VFR for bwi. All system operating normally. Approximately 26 NM from bwi lost alternator. Approach cleared aircraft direct bwi. On ground found problem to be alternator belt slipped of pulley. Notified FBO aviation maintenance for repair. Belt was reinstalled. Departed bwi VFR for cge. Pilot performed long run-up to ensure all system operating normally. Unusually long period on ground due to departing traffic (approximately 15-20 mins). All system normal at takeoff. At 23 NM our from bwi alternator stopped producing again. Aircraft was in stage III service. Due to occurrence on previous trip and for safety reasons (aircraft travelng just east of and parallel to the normal approach course to active runways at bwi going in the opp direction) pilot requested maintaining present transponder code and shutdown of all other electrical equipment, including all radios, with notification to patuxent approach upon safe arrival at cge. Baltimore departure approved request. 10 NM (roughly) out from cge, pilot activated one communication radio to verify active runway at cge. Pilot called out downwind leg and turn to final. Upon arrival pilot notified patuxent via telephone. Aircraft taxied directly to maintenance upon landing where mechanic removed cowling to discover belt had slipped off again. Mechanic removed propeller, removed old belt, installed new belt, installed propeller with new o-ring seal, recowled and test ran. System checked okay.

Original NASA ASRS Text

Title: SMA EXPERIENCES ELECTRICAL PROBLEMS.

Narrative: DEPARTED CGE VFR FOR BWI. ALL SYS OPERATING NORMALLY. APPROX 26 NM FROM BWI LOST ALTERNATOR. APCH CLRED ACFT DIRECT BWI. ON GND FOUND PROB TO BE ALTERNATOR BELT SLIPPED OF PULLEY. NOTIFIED FBO AVIATION MAINT FOR REPAIR. BELT WAS REINSTALLED. DEPARTED BWI VFR FOR CGE. PLT PERFORMED LONG RUN-UP TO ENSURE ALL SYS OPERATING NORMALLY. UNUSUALLY LONG PERIOD ON GND DUE TO DEPARTING TFC (APPROX 15-20 MINS). ALL SYS NORMAL AT TKOF. AT 23 NM OUR FROM BWI ALTERNATOR STOPPED PRODUCING AGAIN. ACFT WAS IN STAGE III SVC. DUE TO OCCURRENCE ON PREVIOUS TRIP AND FOR SAFETY REASONS (ACFT TRAVELNG JUST E OF AND PARALLEL TO THE NORMAL APCH COURSE TO ACTIVE RWYS AT BWI GOING IN THE OPP DIRECTION) PLT REQUESTED MAINTAINING PRESENT XPONDER CODE AND SHUTDOWN OF ALL OTHER ELECTRICAL EQUIP, INCLUDING ALL RADIOS, WITH NOTIFICATION TO PATUXENT APCH UPON SAFE ARR AT CGE. BALTIMORE DEP APPROVED REQUEST. 10 NM (ROUGHLY) OUT FROM CGE, PLT ACTIVATED ONE COM RADIO TO VERIFY ACTIVE RWY AT CGE. PLT CALLED OUT DOWNWIND LEG AND TURN TO FINAL. UPON ARR PLT NOTIFIED PATUXENT VIA TELEPHONE. ACFT TAXIED DIRECTLY TO MAINT UPON LNDG WHERE MECH REMOVED COWLING TO DISCOVER BELT HAD SLIPPED OFF AGAIN. MECH REMOVED PROP, REMOVED OLD BELT, INSTALLED NEW BELT, INSTALLED PROP WITH NEW O-RING SEAL, RECOWLED AND TEST RAN. SYS CHKED OKAY.

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.