Narrative:

I had departed alone into a 1700 foot overcast ceiling. I was initially vectored on a heading of 030 degrees towards a VOR and given an initial altitude of 4000 ft. I followed my usual procedure of using the autopilot on IFR flights and had it actived before entering IMC. Before reaching the VOR I was given a direct course to my destination's VOR and told to climb to my final altitude of 5000 ft. I had been at 5000 ft and direct for long enough to be switched to approach from departure; when I realized that I had left my flashlight in my bag in the rear seat. Not wanting to be without any backup illumination in the case of a power failure; I decided to retrieve the flashlight and place it in the bin on the left side of the aircraft where it would be easily accessible. The conditions inside the cloud layer were still providing some light but it was quickly getting darker and I had all of the panel lights turned up to maximum. I had no problem reaching the bag and getting the flashlight; but to place it in the bin required some moving around of other items; so I had to use both hands. My right hand was in front of the control stick and my left was reaching down into the bin while I bent forward to see what I was doing. I secured the flashlight and sat back in my seat; bringing my right hand in contact with the master switch with enough force to switch both the battery and alternator off. I remember hearing the horrifying click and then seeing the pfd and mfd screens fade to black while knowing that I was in IMC completely without any outside reference. My immediate reaction without even thinking was to flip the master switch back on. I then immediately fixed my eyes on the backup instruments at the top of the panel. The backup attitude indicator's power is connected to the master switch so it had begun to spin down; something that I did not realize at the time; but since the power loss had only been for one second or less it was still upright. I focused on maintaining straight and level flight by using the three instruments: attitude indicator; altimeter and airspeed; as I was worried that I would enter a spiral. In fact; during this incident I forgot to include the compass in my scan and so my heading ended up 40 degrees to the left before I re-attained straight and level flight. I had also allowed a climb of 500 ft above my assigned altitude. The G1000 system was going through the start-up process with a very unhelpful logo screen. Finally the pfd announced that that I needed to keep the wings level and it began righting itself while in flight. The mfd displayed nothing except a notice that it had no GPS information. But I now had a single radio which had automatically been tuned to 121.5. I immediately radioed that I had experienced an inadvertent power failure and had lost all of my primary instruments and that I was on the standby instruments. The approach controller radioed back that I was on the emergency channel and to switch to his frequency. I had now calmed down to the point that I could glance away from the standby instruments and I remembered that I had that frequency written down on my knee pad. I tuned back to his frequency and repeated to the controller that I had no primary instruments yet and was on my standby instruments. He calmly acknowledged my situation and gave me a heading of 10 degrees to get back on course. Almost simultaneously the pfd came back online with attitude; heading; and speed information; and the mfd began showing the map. Fortunately all of the flight plan information and my transponder code was still programmed in the G1000. I set the heading bug and engaged the autopilot. I noticed that I was 500 ft above my assigned altitude; so I set a descent in the autopilot to 5000 ft. I then notified the controller that I had my primary instruments back; and that I could continue direct to the VOR. He gave me direct to my destination; and the rest of the flight was completed without further incident. I was very careful not to put my hand anywhere between the stick and the lower panel containing the master switch. I think that there should be some method of securing the master switch in technologically advanced aircraft with the G1000; because of the impact of loss of power is so catastrophic. Seeing your instrument panel being replaced with black screens is very disturbing. I am very glad that the G1000 can right itself in flight. I also believe that the backup attitude indicator and the G1000 should not be controlled through the same switch. While in this case; the momentary power off did not allow the backup to spin down significantly; a slower response time could have lead to a disaster with the backup attitude indicator giving incorrect readings. I still can't hardly believe that this situation occurred; and I will now always be vigilant in doing the only thing I can do to prevent it; keep my hand away from the master switch in flight.

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Original NASA ASRS Text

Title: A DA40 pilot inadvertently turned the Master Electrical Switch off while IMC; disconnecting power from the G1000; PFD; MFD and Standby Instruments. He was able to reestablish power and return the assigned altitude and was given a vector by ATC.

Narrative: I had departed alone into a 1700 foot overcast ceiling. I was initially vectored on a heading of 030 degrees towards a VOR and given an initial altitude of 4000 FT. I followed my usual procedure of using the autopilot on IFR flights and had it actived before entering IMC. Before reaching the VOR I was given a direct course to my destination's VOR and told to climb to my final altitude of 5000 FT. I had been at 5000 FT and direct for long enough to be switched to Approach from Departure; when I realized that I had left my flashlight in my bag in the rear seat. Not wanting to be without any backup illumination in the case of a power failure; I decided to retrieve the flashlight and place it in the bin on the left side of the aircraft where it would be easily accessible. The conditions inside the cloud layer were still providing some light but it was quickly getting darker and I had all of the panel lights turned up to maximum. I had no problem reaching the bag and getting the flashlight; but to place it in the bin required some moving around of other items; so I had to use both hands. My right hand was in front of the control stick and my left was reaching down into the bin while I bent forward to see what I was doing. I secured the flashlight and sat back in my seat; bringing my right hand in contact with the Master Switch with enough force to switch both the battery and alternator off. I remember hearing the horrifying click and then seeing the PFD and MFD screens fade to black while knowing that I was in IMC completely without any outside reference. My immediate reaction without even thinking was to flip the master switch back on. I then immediately fixed my eyes on the backup instruments at the top of the panel. The backup attitude indicator's power is connected to the Master Switch so it had begun to spin down; something that I did not realize at the time; but since the power loss had only been for one second or less it was still upright. I focused on maintaining straight and level flight by using the three instruments: attitude indicator; altimeter and airspeed; as I was worried that I would enter a spiral. In fact; during this incident I forgot to include the compass in my scan and so my heading ended up 40 degrees to the left before I re-attained straight and level flight. I had also allowed a climb of 500 FT above my assigned altitude. The G1000 system was going through the start-up process with a very unhelpful logo screen. Finally the PFD announced that that I needed to keep the wings level and it began righting itself while in flight. The MFD displayed nothing except a notice that it had No GPS Information. But I now had a single radio which had automatically been tuned to 121.5. I immediately radioed that I had experienced an inadvertent power failure and had lost all of my primary instruments and that I was on the standby instruments. The Approach Controller radioed back that I was on the emergency channel and to switch to his frequency. I had now calmed down to the point that I could glance away from the standby instruments and I remembered that I had that frequency written down on my knee pad. I tuned back to his frequency and repeated to the Controller that I had no primary instruments yet and was on my standby instruments. He calmly acknowledged my situation and gave me a heading of 10 degrees to get back on course. Almost simultaneously the PFD came back online with attitude; heading; and speed information; and the MFD began showing the map. Fortunately all of the flight plan information and my transponder code was still programmed in the G1000. I set the heading bug and engaged the autopilot. I noticed that I was 500 FT above my assigned altitude; so I set a descent in the autopilot to 5000 FT. I then notified the Controller that I had my primary instruments back; and that I could continue direct to the VOR. He gave me direct to my destination; and the rest of the flight was completed without further incident. I was very careful not to put my hand anywhere between the stick and the lower panel containing the master switch. I think that there should be some method of securing the Master Switch in technologically advanced aircraft with the G1000; because of the impact of loss of power is so catastrophic. Seeing your instrument panel being replaced with black screens is very disturbing. I am very glad that the G1000 can right itself in flight. I also believe that the backup attitude indicator and the G1000 should not be controlled through the same switch. While in this case; the momentary power OFF did not allow the backup to spin down significantly; a slower response time could have lead to a disaster with the backup attitude indicator giving incorrect readings. I still can't hardly believe that this situation occurred; and I will now always be vigilant in doing the only thing I can do to prevent it; keep my hand away from the Master Switch in flight.

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.