A PA31 cargo pilot departed pdx in very low visibility conditions with known alternator problems.

Attributes
ACN	572097
Time
Date	200301
Day	Tue
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : pdx.airport
State Reference	OR
Altitude	agl single value : 0
Environment
Flight Conditions	IMC
Weather Elements	Fog
Light	Night
Aircraft 1
Controlling Facilities	tower : ilm.tower
Operator	common carrier : air taxi
Make Model Name	PA-31 Navajo Chieftan/Mojave/Navajo T1020
Operating Under FAR Part	Part 91
Flight Phase	ground : parked ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Person 2
Function	maintenance : technician
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : company policies non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	other
Supplementary
Problem Areas	Maintenance Human Performance Weather Flight Crew Human Performance Aircraft Company
Primary Problem	Flight Crew Human Performance

Narrative:

The aircraft had been having a problem with an intermittent alternator. During startup, the belt on the alternator squealed for 15-20 seconds before it went quiet. Thinking everything was normal, I departed for the flight. Upon arrival and postflt inspection, I discovered that the belt had broken. During the flight, I had noticed that the 'altitude out' light was illuminated. Actions I could have taken to prevent this would have been to shut down the aircraft at the first sound of the noise, and have it inspected by a mechanic. Contributing factors for continuing with the flight was the planned inspection by a mechanic later that day, at a different airport, of the alternator. I had made the flight on a single alternator.

Original NASA ASRS Text

Title: A PA31 CARGO PLT DEPARTED PDX IN VERY LOW VISIBILITY CONDITIONS WITH KNOWN ALTERNATOR PROBS.

Narrative: THE ACFT HAD BEEN HAVING A PROB WITH AN INTERMITTENT ALTERNATOR. DURING STARTUP, THE BELT ON THE ALTERNATOR SQUEALED FOR 15-20 SECONDS BEFORE IT WENT QUIET. THINKING EVERYTHING WAS NORMAL, I DEPARTED FOR THE FLT. UPON ARR AND POSTFLT INSPECTION, I DISCOVERED THAT THE BELT HAD BROKEN. DURING THE FLT, I HAD NOTICED THAT THE 'ALT OUT' LIGHT WAS ILLUMINATED. ACTIONS I COULD HAVE TAKEN TO PREVENT THIS WOULD HAVE BEEN TO SHUT DOWN THE ACFT AT THE FIRST SOUND OF THE NOISE, AND HAVE IT INSPECTED BY A MECH. CONTRIBUTING FACTORS FOR CONTINUING WITH THE FLT WAS THE PLANNED INSPECTION BY A MECH LATER THAT DAY, AT A DIFFERENT ARPT, OF THE ALTERNATOR. I HAD MADE THE FLT ON A SINGLE ALTERNATOR.

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.