I'm a relatively new, certificate holding, remote pilot and I just experienced my first crash. I'm hoping those with more experience can give insight as to possible causes so I can learn from this mistake and move on. The DJI Phantom 4 fell from and altitude of 300 feet AGL and appears to be a total loss. Fortunately we did purchase insurance so things could be worse!
Weather conditions were generally favorable with very light wind (<5mph), great visibility (10 mi.), moderate temperature (85 degrees F), and moderate humidity (66%). I was descending from 395 to 311 feet AGL and rolling simultaneously to keep my subject in the camera frame. Immediately prior to entering an uncontrolled barrel roll and free fall, the drone was moving horizontally at 27 mph and vertically at 11 mph. This is a maneuver I had done multiple times. No setpoints were adjusted that would have permitted me to operate the drone in any manner outside of its default functionality. No warnings or alarms were present. The compass was operating normally and did not need calibrating (per the app). The drone had 6 hours of flight time on it and was still in "new" condition prior to the crash.
The only thing I can come up with is that the 100% descend and 100% pitch, coupled with the moderately humid air caused the drone to lose lift. I suspect operator error on my part, but feel like I was operating the drone as its designed to do and had no indication that I was performing an unsafe maneuver. Can anyone confirm, and maybe provide some pointers on pitching/rolling/yawing/descending simultaneously? Do I just need to slow down?