After many months of perfect flights, it seems we too had to have our doom. No one was injuried cause we always fly without people underneath but our copter suffered some damages (it was a test flight - recovered the most parts). Good news is that we're building another one just now but we would like to know what happened or understand our mistakes. We run on MK electronics and they're covered with a plastic dome; we do not rely on automatic or semi-automatic functions; always manual control. From what we can understand reading the log, the main cause is (should be) a motor failure. Any help would be really appreciated, especially now: we're considering DJI electronics over MK. Attached is the GPX file. Ciao!