Narrative:

On a routine flight; I experienced problems with the avionics in my cessna 182M. Both my GNS403W GPS/navigation/communication and my king KLX130 GPS/communication began cutting in and out as did my transponder. Added to the problem; both communications began an oscillating background noise that increased in intensity until all communication was drowned out. At this time; I was still on departure control and about to switch to center. Fearing damage to my avionics and the possibility of electrical fire; I turned off all electric power and went to my battery powered GPS III pilot and my icom radio; which is equipped to plug into the external antennae; and with receptacles for my headset. Following the aviate; navigate; communicate sequence; I had no trouble keeping the aircraft level and reasonably straight as we were in VMC. I turned the GPS on first; and then; while it was warming up and getting a position; I got the hand held icom out of the glove box; and hooked it into the external antennae receptacles and my headset. The icom was completely dead. At that point; I removed the battery pack from the icom; and began removing and replacing the ten aa batteries with one hand while I flew the plane with the other - no easy task. I only had eight fresh batteries and after replacing those; I tried the icom again. It was still dead. Later testing showed that there was still one completely dead battery; which kept the other from powering up the icom. At that point; I gave up on communicating and turned my attention pack to navigating. Checking the compass; I realized that I had let the heading drift a full 90 degrees from northwest to southwest. Checking the GPS; there was nothing on it except the message page saying 'you are in a restricted area.' having little idea exactly were I was; not being as familiar as I should have been with the portable GPS operation; and having let my preoccupation with the icom radio; divert my attention from navigating. I decided it was time to declare an emergency and ask for help. I turned the electrical power back on; and discovered that I could communicate for fifteen seconds or so before both sending and receiving was interrupted. I first called center on 121.5; declared an emergency; and asked for a vector to the nearest airfield. Then the radio failed again. On my second attempt an airline flight relayed a message from center telling me to contact them on their regular frequency for that area. On my third attempt; I did reach center; and asked again for nearest airfield and vector. They provided me with a vector back to my departure; and I took up that heading. Each of these communications lasted about fifteen seconds before I had to turn the power off again. Once settled on a course back to ZZZ; I turned my attention back to the GPS; and entered a 'direct to' ZZZ command. After that; things settled down. I turned the electrical on again long enough to announce that I would do a straight-in approach to runway 17 at ZZZ; without further communication. Approach acknowledged and gave me permission to land without communication. I landed without further problems and was met by two crash trucks; etc. As there was never an electrical fire; once I was on the ground; the emergency was over. I still don't know if I was ever actually in a restricted area. Lessons learned; back-up equipment is only as good as your familiarity with it; and all battery powered equipment should be checked before every flight. Also; the aviate/navigate/communicate rule only works if you don't allow yourself to get bogged down in one of the three to the exclusion of the other two.

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Original NASA ASRS Text

Title: A C182RG pilot suffered the intermittent loss of all navigation and communications systems.

Narrative: On a routine flight; I experienced problems with the avionics in my Cessna 182M. Both my GNS403W GPS/NAV/Communication and my King KLX130 GPS/Communication began cutting in and out as did my transponder. Added to the problem; both communications began an oscillating background noise that increased in intensity until all communication was drowned out. At this time; I was still on Departure Control and about to switch to Center. Fearing damage to my avionics and the possibility of electrical fire; I turned off all electric power and went to my battery powered GPS III Pilot and my ICOM radio; which is equipped to plug into the external antennae; and with receptacles for my headset. Following the aviate; navigate; communicate sequence; I had no trouble keeping the aircraft level and reasonably straight as we were in VMC. I turned the GPS on first; and then; while it was warming up and getting a position; I got the hand held ICOM out of the glove box; and hooked it into the external antennae receptacles and my headset. The ICOM was completely dead. At that point; I removed the battery pack from the ICOM; and began removing and replacing the ten AA batteries with one hand while I flew the plane with the other - no easy task. I only had eight fresh batteries and after replacing those; I tried the ICOM again. It was still dead. Later testing showed that there was still one completely dead battery; which kept the other from powering up the ICOM. At that point; I gave up on communicating and turned my attention pack to navigating. Checking the compass; I realized that I had let the heading drift a full 90 degrees from northwest to southwest. Checking the GPS; there was nothing on it except the message page saying 'you are in a restricted area.' Having little idea exactly were I was; not being as familiar as I should have been with the portable GPS operation; and having let my preoccupation with the ICOM radio; divert my attention from navigating. I decided it was time to declare an emergency and ask for help. I turned the electrical power back on; and discovered that I could communicate for fifteen seconds or so before both sending and receiving was interrupted. I first called Center on 121.5; declared an emergency; and asked for a vector to the nearest airfield. Then the radio failed again. On my second attempt an airline flight relayed a message from Center telling me to contact them on their regular frequency for that area. On my third attempt; I did reach Center; and asked again for nearest airfield and vector. They provided me with a vector back to my departure; and I took up that heading. Each of these communications lasted about fifteen seconds before I had to turn the power off again. Once settled on a course back to ZZZ; I turned my attention back to the GPS; and entered a 'Direct To' ZZZ command. After that; things settled down. I turned the electrical on again long enough to announce that I would do a straight-in approach to Runway 17 at ZZZ; without further communication. Approach acknowledged and gave me permission to land without communication. I landed without further problems and was met by two crash trucks; etc. As there was never an electrical fire; once I was on the ground; the emergency was over. I still don't know if I was ever actually in a restricted area. Lessons learned; back-up equipment is only as good as your familiarity with it; and all battery powered equipment should be checked before every flight. Also; the aviate/navigate/communicate rule only works if you don't allow yourself to get bogged down in one of the three to the exclusion of the other two.

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.