Posted this over on SparkPilots and posting here too (Hope that’s allowed - delete if not)
Was flying my Spark on Friday checking out ice conditions off of a local beach area that I have flown from numerous times and towards the end of the flight GO4 announced it was in Atti Mode. Glancing at the phone screen it then went to Compass Error, then back to Atti mode and eventually back to normal flight. The AC was in VLOS the whole time so when it went to Atti mode, I turned around and headed back. The compass error gave me a scare as I was worried about loosing control of the AC, however this does not appear to have happened as I was able to get back and land. I was flying over water that had frozen then thawed so there were lots of ice chunks floating around - would have been impossible to recover the AC if it had went down. The launch area was a grassy area covered in wet snow just up from the beach. It is an area I have launched in numerous times and as far as I know there was no metal nearby.
I have owned my Spark for just over 2 years and this is the first time I have ever had a compass error. The log file is linked below. Problems start at 5m 47.8s with Yaw Errors. I would really like to know what happened so that this does not happen again, so any help in figuring this out is greatly appreciated.
Additional info: I hand launch my Spark most times and did so this time as well.