Hello, I am running an S550 frame with APM 2.6 with external compass/GPS which has been flying without any real problems for a few months now. Yesterday I took it out and had a flight around the field behind my house, no problems and everything stable even though it was a little windy. Later on that evening I decided to take it out again as the wind had dropped, just basic stuff, hovering and flying slowly around the field. After approx 9 mins I was about to call it a day (low battery had not sounded yet) and come in to land when it suddenly flipped over and tumbled to the ground from around 30m totally destroying the frame. Unfortunately as I had only nipped out for a quick flight I didn't have my ground station running so no telemetry logs. I did however manage to download the log directly off the AMP. Most of the flight was in loiter mode, wind was fairly calm apart for the odd little gust, I wasn't pushing it anywhere near its limits and the battery voltage when I recovered it was 15.2v, also all the wiring was intact. So I cannot understand why this would happen but a similar thing happened a couple off weeks ago almost in the same place but at a much lower altitude resulting in a broken arm and prop.
Here is a link to the video https://youtu.be/fRwoSVDlyEI
Does anyone have any suggestions as to what could be casing it? I have just ordered a new frame but I am reluctant to fly it again until I get to the cause.
Log files are also attached.
S550 Hexacopter Frame
EMAX 2216 810kv Motors with 1045 props
Hobbywing XRotor 40A ESC's
Zippy 4s 5000mA 35C Lipo
APM 2.6 with GPS and AMP Power Module
FlySky TH9X 9 Channel Radio
433Mhz MavLink Telemetry Radio
SJ4000 Wifi Camera
Sony 1/3 CCD Flight Camera
5.8Ghz 600mW Boscam FPV Transmitter with circular polarised antenna
Turnigy Aircraft LED kit