crash when using grid mission

I’ve been using pix4d for 2 months and had done many flight missions with DJI Phantom 4 Pro

I usually set grid mission 500 x 300 meters in size and in altitude of 100 meters

Today for the second time the drone lost control, refused to go to starting point, and began descend haphazardly in high speed. Luckily the drone landed on a paddy field, the first crashing episode totally broke the drone apart.

I was using Samsung Galaxy Note Fan Edition. Could anyone explain what probably causes this malfunction?

Hi,

We are sincerely sorry to hear about this bad experience. The drone is actually responsible for not destroying itself and going out of control. The app tells the drone where to go and when to take pictures, and when it does not work this is due to issues on Pix4D side. But our app is not responsible when the drone crashes as we cannot give instructions that would override the safe behavior of the drone. When the situation becomes out of control, it is coming from the drone as it is the “driver” meaning the aircraft knows how to fly. 

Normally taking over manual control should prevent incidents from happening. Were you able to take over manual control? Have you tried to tap  Abort  in Pix4Dcapture to interrupt the mission or to press the return-to-home (RTH) button of the controller before the drone goes too far away and loses the connection? When the connection is lost, the fail-safe behavior that you define in the drone app should be triggered. 
Also, could you confirm the latest drone’s firmware and apps installed?

Again we are very sorry for the drone and we hope these answers are useful to understand what happened.

Best,