Narrative:

Aircraft experienced electrical failure while enroute in VMC under IFR flight plan which resulted in loss of navigational and communications equipment. Loss of navigational and communications equipment occurred when 30 NM from destination and started as a partial loss. Within a minute both GPS (GNS-430W) and radio (kx-155) became inoperable. During the recognition and trouble shooting of the problem; the aircraft drifted 4 NM left of course and came within 2 NM (but never entered) R-5701. Once I noticed the drift from course; I was able to proceed visually to the field. I employed a hand held radio (vertex pilot III) but had difficulty with two way communication with approach. I was able to be handed off to tower where I was able to communicate with the tower and landed uneventfully. My aircraft has an electrically powered HSI; and the heading indication became unreliable as the main bus voltage dropped. All primary navigation was lost; including GPS; VOR; ADF and DME. Communications were temporarily rendered inoperative until I employed a hand held radio. Once I realized the HSI was unreliable I used the magnetic compass as primary for heading until the airport was in sight. While I did not deviate from altitude; I did deviate from heading. Upon loss of electrical power; I might have used the magnetic compass heading earlier and maintained visual navigation during the troubleshooting. In review of my actions; I believed I otherwise responded appropriately to the in-flight electrical failure. I kept the wings level and aircraft trimmed. I was able to employ the hand held radio relatively quickly. Factors that would have helped with the situation would have been: 1) having a backup; battery powered navigation system; and 2) having a connection to the ships external mounted antennas.

Google
 

Original NASA ASRS Text

Title: M20 pilot experienced electrical failure while enroute in VMC under IFR flight plan which resulted in loss of navigational and communications equipment. Hand held VHF was used to facilitate landing at destination airport.

Narrative: Aircraft experienced electrical failure while enroute in VMC under IFR flight plan which resulted in loss of navigational and communications equipment. Loss of navigational and communications equipment occurred when 30 NM from destination and started as a partial loss. Within a minute both GPS (GNS-430W) and Radio (KX-155) became inoperable. During the recognition and trouble shooting of the problem; the aircraft drifted 4 NM left of course and came within 2 NM (but never entered) R-5701. Once I noticed the drift from course; I was able to proceed visually to the field. I employed a hand held radio (Vertex Pilot III) but had difficulty with two way communication with Approach. I was able to be handed off to Tower where I was able to communicate with the tower and landed uneventfully. My aircraft has an electrically powered HSI; and the heading indication became unreliable as the main bus voltage dropped. All primary navigation was lost; including GPS; VOR; ADF and DME. Communications were temporarily rendered inoperative until I employed a hand held radio. Once I realized the HSI was unreliable I used the magnetic compass as primary for heading until the airport was in sight. While I did not deviate from altitude; I did deviate from heading. Upon loss of electrical power; I might have used the magnetic compass heading earlier and maintained visual navigation during the troubleshooting. In review of my actions; I believed I otherwise responded appropriately to the in-flight electrical failure. I kept the wings level and aircraft trimmed. I was able to employ the hand held radio relatively quickly. Factors that would have helped with the situation would have been: 1) having a backup; battery powered navigation system; and 2) having a connection to the ships external mounted antennas.

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.