dpbarnes
New Member
I have a garmin 650 hooked to Skyview with their transponder and adsb equipment. On a flight from Indiana to Florida for Sun n Fun I had three warnings from skyview that the transponder lost gps input. It happened at different times during the five hour flight. While at sun n fun I visted the faa adsb booth and they brought up the flight. At the time of warnings the faa showed a slight jump in my position. Sometimes as much as a 1 1/2 miles. They looked back at my last 30 or so flights and saw the same pattern. Since the flights were shorter they happened every third flight or so. I remembered about the same frequency of transponder gps loss warnings on skyview. The gps signal on the 650 was strong the faa was unsure of the problem. They thought a software problem with skyview or garmin. So I waited to see if maybe a future upgrade would fix it. The reason for this long post is I think I found the problem. It is not where I would ever look. About two weeks ago I went for one of my typical local one hour flights and had almost a constant on and off warning from skyview about the loss of gps. Part way into the flight I noticed my charging voltage was at about 25 volts from a normal of about 28 volts. So after landing I took apart the delco style alternator on my io-550 and found one of the three stator windings burnt and showing a short to ground. I went to a local alternator rebuilder and got a similar looking one and replaced it. Since then I replaced that with the correct one. I have about four hours on the plane with no warnings. Not long enough to be sure but I have my fingers crossed. I thought I would share in the hopes if might help others. Not sure why but that short must of generated a lot of interference. It may have been intermittent for a long time.
Dan Barnes Lancair ES 150 hours
Dan Barnes Lancair ES 150 hours