Hi, I been flying Spark since December with no issues; I think in that time it switched to ATTI mode once or twice. But recently while flying in my typical "test" area where I have never had a problem with GPS, it switched to ATTI mode once per short flight. Just wondering if anyone has seen this? May have to return to DJI for repair / calibration. One last thing: after the third incident in as many days I re-calibrated everything on the Spark and on the fourth flight it again lost GPS.