Is this a pilot error or Malfunction ?

[Meta4]

Before the crash there were lots of messages saying that some of the motors are blocked.

any idea what would cause a blocked motor message cause when it fell there wasnt anyhting there

Before the crash ?? Check the timing.
Those messages were the crash and confirming impact with the ground.
They happened well after the cause of the crash.

 

[Meta4]

It’s possible a bird strike ?

No

 

[boblui]

Before the crash ?? Check the timing.

Check the altitude ....

 

[Meta4]

Check the altitude ....

I did .. It's right as the drone crashes into the ground.
This is nothing like "before the crash"
If it was indicative of a cause, it would be when the drone was 18 metres up in the air.

 

[boblui]

I did .. It's right as the drone crashes into the ground.
This is nothing like "before the crash"
If it was indicative of a cause, it would be when the drone was 18 metres up in the air.

Assuming that its not bird strike the crash happened when the drone hit the ground but motor blocking started 18 m above the ground hence before the crash

 

[Meta4]

motor blocking started 18 m above the ground hence before the crash

Do you see any before 8:23?
What height was the drone at at 8:23?

 

[boblui]

Do you see any before 8:23?
What height was the drone at at 8:23?

I did see the wild rocking starting at 8:21.5 and motor blocking message was issued 1.5 sec later. As the OP said that there was no obstacles like buildings or poles there, the crash could not have happened at 8:21.5 unless it was a bird strike. There remains a high possibility that some mechanical failure of the motors occurred at that moment.

 

[Meta4]

I did see the wild rocking starting at 8:21.5 and motor blocking message was issued 1.5 sec later.

... and 1.5 sec later is when the drone hit the ground.
Check the altitude !!!
It's all spelled out in post #10.

 

[Deleted Member 997]

The first indication of a problem shows in the data at about 8:21.4 when the drone rolls to one side much further than normal and then pitches forward past the normal limits.
It also starts to spin in a clockwise direction despite you giving rudder input the opposite way.
The drone also begins to lose height.
The pitch, roll and yaw data is extreme showing the drone spinning amd tuimbling out of the sky.

The crash impact was at about 8:23.3 and altitude and speed data after that shows some crazy numbers due to the effect of the impact on the sensors.

This incident was not due to piloting or battery levels.
The data is indicative of the loss of a prop or motor.

Good analysis, without looking at the data and you describing it... its loss of rotor

 

[Deleted Member 997]

Good analysis, without looking at the data and you describing it... its loss of rotor

If you made no control inputs and it rolled. That means one or 2 rotors failed and stop providing lift, hence the roll and spiral crash

 

[DagDerniT]

Looks like another crash due to losing a prop. That roll is usually the sign of it and since these are not hexacopters, they are unable fly with only 3... I dont thing that Dji will cover a prop loss as it is pilot error but i would still try.

 

[Makwaii]

@DagDerniT thats the thing it wasn't as if it was loose upon take off it was flying fine for 8 minutes before the crash. Is there anything I could even say to dispute it if they do deny that claim?

 

[hiflyer201]

The pilot sa

Looks like another crash due to losing a prop.

the pilot stated the props were still attached. Meta suspected motor failure ..I'm thinking DJI will replace without issue.

 

[Starz]

Just love reading someone questioning information from Meta4.
Thanks for the fun!

 

[DanMan32]

I agree with Meta. OP's original post shows sudden drop start just before 8m23s and continue through all of that second.

The alerts show at 8m23s but does not show sub-second time. It makes more sense the prop obstruction alerts are for when it hit the ground where the ground was obstructing the props.

Loose props are usually reported just that way, or motor overspeed.

 

[iglou7]

any powerlines?

 

[Meta4]

any powerlines?

If the loss was due to a collision with powerlines or any other obstacle, there would be clear evidence of that in the flight data (and there wasn't any).

 

[DagDerniT]

@DagDerniT thats the thing it wasn't as if it was loose upon take off it was flying fine for 8 minutes before the crash. Is there anything I could even say to dispute it if they do deny that claim?

When you talk to the Dji Representative, make sure to let them know that you thoroughly checked each and every propeller for damage, and that they were properly connected to the motors. In the future make sure that you the props click in and are mounted perfectly level. Take a magnifying glass if you need to and look to make sure. Sorry that you are going through this and not out having fun flying it. Good luck!

 

[slup]

Already 2 pages long & no one have asked for the DAT log yet? The mobile device DAT log ending with FLY031.DAT will clearly show every detail in this, retrieve it and attach it here, then we certainly will be able to tell the reasons for this AC to loose thrust from the front left side. The accelerometer sensor readings there can say if anything hit the AC before loosing thrust, the motor rpm's & motor currents will let us know if it was a prop or a motor failure.

That it was a lost thrust issue is pretty clear & straight forward ... the incident started at 501,3sec.

-Just before the incident moment, the elevator stick was just released from full ... making the pitch in the chart (Green graph) to go heavily positive for breaking.
-During the breaking the OP applied max negative throttle to descend (Light bluish graph)... It's this that starts the initial height loss.
-Meanwhile breaking & commanding loosing height the OP uses a larger command with the rudder stick (Purple graph) to rotate negative (CCW).
-But at 501,3sec ... still applying both throttle & rudder sticks, the AC pitches down (Green) & rolls left (Blue) heavily & abrupt ... the tilt angle (Red) goes in an instant from 33 degrees (about max according to the spec.) to 73 degrees.

All this gives a very strong indication of a failure in the front left corner ...



The discussed message below, comes 2sec after the incident have started ... so it's irrelevant to the incident.



With all this said ... we still can't say for sure if it was a motor or a prop that failed. With a front left corner failing the AC should start to rotate CW (Darker green graph) ... but it doesn't, it continues to rotate CCW (negative) as per the commanded rudder input there. At 501,7sec we see the first CW twitch ... after that we get a more of a oscillation than a rotation. This can be due to a partly damaged prop or a motor that rotates but slowly seizes together. The mobile device DAT log is needed to be able to tell ...

 

[Makwaii]

is it this one? Now that you mention it when the drone hit the floor only the front left arm came loose from the shell, all propellers were still intact prior to the crash but the front left one snapped in half possibly from the drone taking the fall face first