Help Interpreting Flight Log and Reasons for Crash

[Cap'n Chip]

I'm a new, certificate holding, remote pilot and I just experienced my first crash. I have 6 hours of commercial flight time under my belt. A link to the flight log is provided below and I also attached a PDF text version. Around 11 min 30 sec is immediately prior to the crash. I'm hoping those with more experience can give insight as to possible causes so I can learn from this mistake and move on. The DJI Phantom 4 fell from and altitude of ~316 feet AGL and appears to be a total loss. Fortunately we did purchase third-party insurance so things could be worse!

Weather conditions were generally favorable with very light wind (<5mph), great visibility (10 mi.), moderate temperature (85 degrees F), and moderate humidity (66%). I was descending from 389 to 316 feet AGL and rolling simultaneously to keep my subject in the camera frame. Immediately prior to entering an uncontrolled barrel roll and free fall, the drone was moving horizontally at 27 mph and vertically at 11 mph. This is a maneuver I have done multiple times before. The drone had 6 hours of flight time on it and was still in "new" condition prior to the crash.

I was flying over an open field with no obstructions and no obvious sources of compass interference, although my flight log indicates at least one obstacle avoidance and multiple notifications to "move aircraft away from interference." I have seen the latter notification on other flights but every time I would try to calibrate the compass, it told me it was fine. This notification would sometimes come and go several times with no observable impact to the operation of the drone.The only other thing I can come up with is that the 100% descend and 100% roll, coupled with the moderately humid air caused the drone to lose lift. I suspect operator error on my part, but feel like I was operating the drone as its designed to do and had no indication that I was performing an unsafe maneuver. Can anyone confirm, and maybe provide some pointers on pitching/rolling/yawing/descending simultaneously? Do I just need to slow down?

Any tips for dealing with DJI? They want me to send the drone and remote in...but it is literally destroyed and in multiple pieces so I'm not sure what good that would do! I offered the flight log to no avail.

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

 

[Meta4]

Can anyone confirm, and maybe provide some pointers on pitching/rolling/yawing/descending simultaneously? Do I just need to slow down?

This incident had nothing to do with the compass, humidity or going too fast.
Things turned bad at 11:39.1.
The drone was descending with full left stick down and you were rotating slowly clockwise with light rudder input, when the drone suddenly started spinning anti-clockwise very fast, losing height and rolling hard left and pitching at crazy angles.
It was tumbling down quickly.

This is due to the loss of either a prop or a motor.
Were all props still attached when you found the wreckage?

Any tips for dealing with DJI? They want me to send the drone and remote in...but it is literally destroyed and in multiple pieces so I'm not sure what good that would do! I offered the flight log to no avail.

You should synch your flight records to upload to DJI's server.
Start an online chat with their help people and they will get things started for you.

Since it was a new drone, DJI need to examine it for a warranty claim.
Inside the case, there is a "black-box data recorder that records even more data than is in the .txt file from your phone or tablet and they will want to analyse that data.

 

[Cap'n Chip]

This incident had nothing to do with the compass, humidity or going too fast.
Things turned bad at 11:39.1.
The drone was descending with full left stick down and you were rotating slowly clockwise with light rudder input, when the drone suddenly started spinning anti-clockwise very fast, losing height and rolling hard left and pitching at crazy angles.
It was tumbling down quickly.

This is due to the loss of either a prop or a motor.
Were all props still attached when you found the wreckage?

You should synch your flight records to upload to DJI's server.
Start an online chat with their help people and they will get things started for you.

Since it was a new drone, DJI need to examine it for a warranty claim.
Inside the case, there is a "black-box data recorder that records even more data than is in the .txt file from your phone or tablet and they will want to analyse that data.

One prop was missing and I assumed it detached upon impact, but cannot confirm. The crash site is very tall grass so I was unable to locate the prop.

Thanks for the clarification on why DJI wants to inspect the unit. I'll start the online process with them.

 

[WV. Rootman]

The obstacle avoidance was most likely because you were facing the sun. That is a common occurrence. If it is interfering with your flying, turn it off. You really don’t need it at 300 ft.

 

[Andy9]

Just something maybe irrelevant to this incident but it comes to my mind.
You were flying down, rotating and flying backward or forward, doesn't matter.
If in that moment you unintentionally push the right hand button on the RC you may stop the motors in flight! (ESC)

 

[bsartist]

I once read a similar story here and turned out that careful inspection of the map at crash location showed very high wires not visible to the naked eye from ground level. Just a thought. But missing prop seems more likely at this point.

 

[Cap'n Chip]

This incident had nothing to do with the compass, humidity or going too fast.
Things turned bad at 11:39.1.
The drone was descending with full left stick down and you were rotating slowly clockwise with light rudder input, when the drone suddenly started spinning anti-clockwise very fast, losing height and rolling hard left and pitching at crazy angles.
It was tumbling down quickly.

This is due to the loss of either a prop or a motor.
Were all props still attached when you found the wreckage?

You should synch your flight records to upload to DJI's server.
Start an online chat with their help people and they will get things started for you.

Since it was a new drone, DJI need to examine it for a warranty claim.
Inside the case, there is a "black-box data recorder that records even more data than is in the .txt file from your phone or tablet and they will want to analyse that data.

Just want to thank everyone for their input and to provide an update. The unit was sent to DJI and they confirmed that that it was most likely a detached prop which was covered under warranty. They are basically replacing every component so I'll essentially have a new drone. I'm impressed with DJI for the ease of getting this resolved. I didn't have to pay a dime for shipping or anything.

 

[cneedelman]

They will most likely send you a new drone. I just sent my controller in for repair and I got a new one back.