Problem? Flyaway
Was unit in a crash? Yes
What have you tried so far? Analysing flight data, talking to DJI support.
My account of what happened:
I was flying the aircraft outdoors when it decided to fly away, crash into a cliff face and drop into a river. I was unable to retrieve the aircraft from the river without a risk to life. I spent well over an hour assessing the situation after the crash before abandoning the recovery attempt.
A few comments from the scene:
- The data was logged during the entire event, indicating to me that signal between phone and drone was not lost.
- Line of sight was maintained until shortly before the drone hit the water.
- The only warning message before the crash was with regard to the maximum altitude, which was only at 2.5m.
- No other warning messages were received before the crash.
- The aircraft was not observed to initiate obstacle avoidance before colliding with the cliff face.
- I did not initiate RTH at any time during the flight.
- After loss of control, I pressed the pause button with no effect on the drone side.
- I tried stopping the aircraft with the RC after loss of control with no effect on the drone side.
- All other warning messages were received after the crash.
I was aware of the lack of GPS signal. However, I was mistakenly confident in the drone's control and fail-safe algorithms. I have attached my own analysis and labelled the important events, which are summarised as follows:
00.0s Takeoff
20.9s Complete loss of control
27.6s Drone crashes here
DJI Support are refusing to acknowledge that the drone crashed at 27.6s, saying instead the crash occurred at the very end of the measurement, at T=48s. They first said the vision system worked until T=30s. In the most recent email they are saying the vision system was not working between T=20s and T=22s, which is why the velocity spiked. In their words:
"For flyaway cases, we usually judge the crash by whether there was abnormal abrupt change of the attitude angles.
T=00:20, the vision system stopped working as the environmental conditions was not met for its working. There was no GPS signal, the aircraft could not figure out the horizontal velocity correctly; So the velocity showed now had no reference value; Also, according to the attitude angles and the vertical velocity, we can confirm that no crash happened at this Moment."
A quick note, if the velocity value is not correct without vision positioning, shouldn't this mean the attitude (yaw, pitch, roll) values they are using to justify their argument also be incorrect..?
I remember the timeline of events during that flight quite vividly. However, I have looked at this data a lot over the last 2 weeks and would very much appreciate a second set of eyes from this community.
What device are you using ( iphone , ipad, Samsung , etc)? Huawei P8 lite
What firmware are you running ( aircraft, remote controller)? Latest at the time of the crash
What Go app version are you using? Latest at the time of the crash
Any modification? No
Did you change anything or install any apps? No
Do you have a video or pictures of the problem? Was not recording at all during that flight
My flight log is here: DJI Flight Log Viewer - PhantomHelp.com
Thank you very much in advance.
Was unit in a crash? Yes
What have you tried so far? Analysing flight data, talking to DJI support.
My account of what happened:
I was flying the aircraft outdoors when it decided to fly away, crash into a cliff face and drop into a river. I was unable to retrieve the aircraft from the river without a risk to life. I spent well over an hour assessing the situation after the crash before abandoning the recovery attempt.
A few comments from the scene:
- The data was logged during the entire event, indicating to me that signal between phone and drone was not lost.
- Line of sight was maintained until shortly before the drone hit the water.
- The only warning message before the crash was with regard to the maximum altitude, which was only at 2.5m.
- No other warning messages were received before the crash.
- The aircraft was not observed to initiate obstacle avoidance before colliding with the cliff face.
- I did not initiate RTH at any time during the flight.
- After loss of control, I pressed the pause button with no effect on the drone side.
- I tried stopping the aircraft with the RC after loss of control with no effect on the drone side.
- All other warning messages were received after the crash.
I was aware of the lack of GPS signal. However, I was mistakenly confident in the drone's control and fail-safe algorithms. I have attached my own analysis and labelled the important events, which are summarised as follows:
00.0s Takeoff
20.9s Complete loss of control
27.6s Drone crashes here
DJI Support are refusing to acknowledge that the drone crashed at 27.6s, saying instead the crash occurred at the very end of the measurement, at T=48s. They first said the vision system worked until T=30s. In the most recent email they are saying the vision system was not working between T=20s and T=22s, which is why the velocity spiked. In their words:
"For flyaway cases, we usually judge the crash by whether there was abnormal abrupt change of the attitude angles.
T=00:20, the vision system stopped working as the environmental conditions was not met for its working. There was no GPS signal, the aircraft could not figure out the horizontal velocity correctly; So the velocity showed now had no reference value; Also, according to the attitude angles and the vertical velocity, we can confirm that no crash happened at this Moment."
A quick note, if the velocity value is not correct without vision positioning, shouldn't this mean the attitude (yaw, pitch, roll) values they are using to justify their argument also be incorrect..?
I remember the timeline of events during that flight quite vividly. However, I have looked at this data a lot over the last 2 weeks and would very much appreciate a second set of eyes from this community.
What device are you using ( iphone , ipad, Samsung , etc)? Huawei P8 lite
What firmware are you running ( aircraft, remote controller)? Latest at the time of the crash
What Go app version are you using? Latest at the time of the crash
Any modification? No
Did you change anything or install any apps? No
Do you have a video or pictures of the problem? Was not recording at all during that flight
My flight log is here: DJI Flight Log Viewer - PhantomHelp.com
Thank you very much in advance.