Narrative:

I was on an IFR flight plan. Approach cleared me to 5;000 after takeoff and then direct. About 20 minutes into the flight and over the lake; approach indicated not receiving mode C and requested that I recycle. I recycled and ATC replied still not receiving mode C; just primary. They then told me to climb to 7;000 feet and center. I began the climb and contacted center. They also told me not receiving mode C and to recycle transponder. I then experienced a loud buzzing sound through the headset. I thought to myself that there were intercom problems and I turned the intercom off and the noise; though not as loud; was still there. I turned the intercom back on and once again asked center if they were receiving mode C. They replied no and it seems seconds later that all avionics went dead in the aircraft. I immediately went to the ammeter gauge and noticed discharge; I slowed the aircraft to gear operating speed and lowered the gear. The gear came down and I immediately felt the drag. I could not get any of the avionics to come back on. To my right; I saw an airport and circled to lose altitude and set up for a landing on the runway. I told my passenger that we have experienced an electrical failure and we are setting up for a landing. I concentrated on airspeed realizing I had no flaps. Unfortunately my 'mindset' at the time was that the gear was down. On long final I thought of overflying the field and requesting a visual from the ground as to whether or not the gear was down. I then realized there was no way to communicate and I concentrated on the landing and watching my airspeed. I came in over the 'numbers' flared and felt the main gear touch and then the gear collapsed and we slid off the runway into the grass. I immediately shut all systems off and we exited the airplane and waited for help. Human performance: my early perception was that I had a transponder problem and I was attempting to determine the cause. I did not think of electrical issues immediately. When I lost all electrical; my thought was to get the gear down as soon as possible due to the electrical failure. My perception was that the gear was down. I had an airport directly to my right and then concentrated on the landing. I was calm and did not feel rushed or any sense of urgency about the situation other than to land and contact center as to what had happened. I was complacent and did not run the emergency checklist for electrical/landing gear problems. I told the FAA inspector that in my mind the gear was down. I also think that due to the closeness of the airport; I let my guard down and gave the landing a priority rather than doing more to troubleshoot the problem and absolutely confirming that the gear was down and locked.

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Original NASA ASRS Text

Title: A BE35's electrical system failed in flight. The pilot thought that the landing gear had extended because of noise and drag but upon landing the gear collapsed.

Narrative: I was on an IFR flight plan. Approach cleared me to 5;000 after takeoff and then direct. About 20 minutes into the flight and over the Lake; Approach indicated not receiving Mode C and requested that I recycle. I recycled and ATC replied still not receiving Mode C; just primary. They then told me to climb to 7;000 feet and Center. I began the climb and contacted Center. They also told me not receiving Mode C and to recycle transponder. I then experienced a loud buzzing sound through the headset. I thought to myself that there were intercom problems and I turned the intercom off and the noise; though not as loud; was still there. I turned the intercom back on and once again asked Center if they were receiving Mode C. They replied no and it seems seconds later that all avionics went dead in the aircraft. I immediately went to the ammeter gauge and noticed discharge; I slowed the aircraft to gear operating speed and lowered the gear. The gear came down and I immediately felt the drag. I could not get any of the avionics to come back on. To my right; I saw an airport and circled to lose altitude and set up for a landing on the runway. I told my passenger that we have experienced an electrical failure and we are setting up for a landing. I concentrated on airspeed realizing I had no flaps. Unfortunately my 'mindset' at the time was that the gear was down. On long final I thought of overflying the field and requesting a visual from the ground as to whether or not the gear was down. I then realized there was no way to communicate and I concentrated on the landing and watching my airspeed. I came in over the 'numbers' flared and felt the main gear touch and then the gear collapsed and we slid off the runway into the grass. I immediately shut all systems off and we exited the airplane and waited for help. Human Performance: My early perception was that I had a transponder problem and I was attempting to determine the cause. I did not think of electrical issues immediately. When I lost all electrical; my thought was to get the gear down as soon as possible due to the electrical failure. My perception was that the gear was down. I had an airport directly to my right and then concentrated on the landing. I was calm and did not feel rushed or any sense of urgency about the situation other than to land and contact Center as to what had happened. I was complacent and did not run the emergency checklist for electrical/landing gear problems. I told the FAA Inspector that in my mind the gear was down. I also think that due to the closeness of the airport; I let my guard down and gave the landing a priority rather than doing more to troubleshoot the problem and absolutely confirming that the gear was down and locked.

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.