An aa-5B alternator malfunctioned during an IMC approach making the aircraft NORDO. The pilot procee...

Narrative:

After initial contact with approach inbound for landing at my filed destination; I experienced a complete electrical failure due to a malfunctioning alternator and as a result was completely NORDO. [I] immediately changed transponder code to 7600 even though the transponder was more than likely inoperative. Weather was generally IFR; although I could see the ground below me so I started a slow circling descent while making calls in the blind until I got below the weather at about 1;500 ft MSL and could maintain marginal VFR. I tried to maintain predictable and set myself up for a straight in for the runway in use using a portable GPS device. When I turned final it was obvious I would not be able to make a landing due to a heavy rail squall directly over the airport. I then proceeded to my filed alternate. I was able to pick up the airport fairly easily and set myself up to overfly the airport down the instrument runway in use at 1;000 ft MSL. I observed light gun signals from the tower directing me to land and rocked my wings in acknowledgment. Made a normal landing and followed a follow-me truck back to the FBO. [I] contacted the tower chief after landing as a follow up. Troubleshot and found a possible loose wire at the voltage regulator. Received a jump start and observed normal charging via the ammeter. Took off from and flew home maintaining VFR and minimizing the use of electrical equipment as a precaution. [I] landed without incident.

Original NASA ASRS Text

Title: An AA-5B alternator malfunctioned during an IMC approach making the aircraft NORDO. The pilot proceeded to his alternate because a rain cell over his destination prevented a safe landing.

Narrative: After initial contact with Approach inbound for landing at my filed destination; I experienced a complete electrical failure due to a malfunctioning alternator and as a result was completely NORDO. [I] immediately changed transponder code to 7600 even though the transponder was more than likely inoperative. Weather was generally IFR; although I could see the ground below me so I started a slow circling descent while making calls in the blind until I got below the weather at about 1;500 FT MSL and could maintain marginal VFR. I tried to maintain predictable and set myself up for a straight in for the runway in use using a portable GPS device. When I turned final it was obvious I would not be able to make a landing due to a heavy rail squall directly over the airport. I then proceeded to my filed alternate. I was able to pick up the airport fairly easily and set myself up to overfly the airport down the instrument runway in use at 1;000 FT MSL. I observed light gun signals from the Tower directing me to land and rocked my wings in acknowledgment. Made a normal landing and followed a follow-me truck back to the FBO. [I] contacted the Tower Chief after landing as a follow up. Troubleshot and found a possible loose wire at the voltage regulator. Received a jump start and observed normal charging via the ammeter. Took off from and flew home maintaining VFR and minimizing the use of electrical equipment as a precaution. [I] landed without incident.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	964254
Time
Date	201108
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	Cheetah Tiger Traveler AA5 Series
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Electrical Wiring & Connectors
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 60 Flight Crew Total 1600 Flight Crew Type 24
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Weather / Turbulence

An aa-5B alternator malfunctioned during an IMC approach making the aircraft NORDO. The pilot proceeded to his alternate because a rain cell over his destination prevented a safe landing.