Solved

[lumalab]

My I2 fell out of the sky with 70% battery life.
I have uploaded a video with the flight log and camera footage.

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Looking to this community to help understand what happened

 

[Dobmatt]

At this level of investigation (having no results of DAT file analysis) we can only speculate. Mother Nature wasn't cooperating, no doubt. You can clearly see a droplet of rain or snow on lens. Heavy rain or ice buildup may disrupt GPS reception, confusing RTH procedure execution. This is, however, unlikely the scenario. Left stick malfunctioning is my best guess ...

 

[lumalab]

hmm I didn't think of that, I will have to test the controller. Wondering why it would come crashing down though, if it was just a problem with the controller. What is a DAT file and how do I retrieve it?

 

[oldcomputech]

When you say “crashing down” do you mean dead stick? By the look of the damage that does not appear the case. Should have been in a lot more pieces if it fell from 400 and hit your truck. Seems like the left stick failed on the controller and / or RTH did not work properly. I believe I heard you say you pressed RTH several times? What version of DJI Go/Android/IOS device are you using? Just a few thoughts. Sorry your drone got flattened.

 

[MEDF]

Dobmatt points to weather conditions, I would belive the icing on propeller blades destroying the lifting force

 

[Chrisls]

"My I2 fell out of the sky with 70% battery life.
I have uploaded a video with the flight log and camera footage."

[Rotor failure would cause the drone to spin, I've seen this happen - not with I2. Probably not rotor or propeller since bird seems stable. My guess would be controller malfunction.

 

[lumalab]

When you say “crashing down” do you mean dead stick? By the look of the damage that does not appear the case.

Yes at the 5:30 mark the drone fell out of the sky. I assume it was 400' (120m) because that is what the altimeter read on the monitor. I was lucky it hit the truck and deflected off, otherwise it would have a lot been worse. Frankly it is a miracle that only one leg was damaged. No idea about the gimbal/camera as my local shop can only fix the drone.

The controller was working at the beginning, so it is very strange that only the left stick would fail.

I was running DJI Go 4 on a CrystalSky monitor with the latest firmware. I can't imagine a more stable configuration, yet it spontaneously crashed. I have no footage of the crash as the x5s was not recording. If there is a way to get the POV camera video off the cache please let me know. As far as I can tell only the gimbal footage is recorded. From now on I will fly with a dashcam on my head.

 

[MEDF]

I don't think the drone rotates during icing as all rotors lose power equally.

 

[Dobmatt]

hmm I didn't think of that, I will have to test the controller. Wondering why it would come crashing down though, if it was just a problem with the controller. What is a DAT file and how do I retrieve it?

This is a file recorded internally after every powering-up procedure. The state of entire system is reflected here, every command and system responds, every warnings etc. etc. However, only experienced eyes can read and interpret such data. You can retrieve flight log file with Assistant 2 software, assuming that the bird is alive after powering up. If your Inspire is still under warranty, DJI will analyze the data and - hopefully - come up with conclusion. If not, somebody may be able to do it for you ...

My guess about RC stick malfunctioning is based on your video narration. It seems that Inspire entered RTH procedure correctly, but wasn't able to descent because left stick input was somehow stuck at full throttle up, therefore overriding landing descent. That's why the drone was actually hovering at maximum allowed attitude of 400', while trying to land simultaneously. Very confusing situation for her brain, you must agree ...

Speculating even further, it's also possible that during your frantic attempts to regain control you've performed cross-stick kill command. It will be reflected in DAT file, if so ...

 

[S White]

Interesting mishap. In my opinion it is very likely that it was related to the environment. I would have never flown in that condition. Anytime you have a cold foggy layer like that, any aircraft entering it is likely to have 'super cooled' water droplets to deal with. Basically that means that unfrozen water is suspended in the air waiting for something solid to attach to, to freeze to. It looks like that is the case here. There is a ton of vortex going on with those four blades spinning. The interesting thing about icing is that often much of the evidence is gone upon landing since much of it has melted. If you did not see anything on the blades, it likely is an issue with the motors and electronics. Seeing water on your lens is evidence of a lot of moisture in the air. The x5s is not water resistant and who knows what issues were developing with it. The fact that the I2 was not spinning seems to indicate that all your props were working. One thing never to underestimate is air turbulence and up drafts. Clouds form that way. My humble guess is that everything was related to the air conditions and mountain environment. Not sure where you were flying but Part 107 regs prohibit flying that close to clouds, and if this was a commercial project the USFS needed to approve it. And of course if this was inside the US national parks boundaries, that is off limits also. All that said, I appreciate greatly your posting. It certainly brings reality to my fears of flying in mountains that are being consumed with a wet cold front......

 

[Starz]

Just a question. Why was the landing gear doing what it was doing?

 

[Dobmatt]

Just a question. Why was the landing gear doing what it was doing?

Are you texting while driving ??? Too lazy to articulate your question better ??? So, here's my answer: I don't know what are you talking about.

 

[Starz]

Are you texting while driving ??? Too lazy to articulate your question better ??? So, here's my answer: I don't know what are you talking about.

Question wasn’t directed to you. Never mind. Hopefully I won’t bother you again and I apologize for my inabilities to be as articulate as yourself.

 

[lumalab]

IMy humble guess is that everything was related to the air conditions and mountain environment. Not sure where you were flying but Part 107 regs prohibit flying that close to clouds, and if this was a commercial project the USFS needed to approve it. And of course if this was inside the US national parks boundaries, that is off limits also. All that said, I appreciate greatly your posting. It certainly brings reality to my fears of flying in mountains that are being consumed with a wet cold front......

I agree, should not of been out in that weather. Of course it was the last day and I was desperate to get some footage. The location was outside the park boundary (Banff Nation Park), in uncontrolled airspace, greater than 30m from people; so legal by Nav Canada regs. Still a bad idea though.

 

[lumalab]

Just a question. Why was the landing gear doing what it was doing?

Don't know if landing coming up and down was my doing or if it was happening automatically. I was pushing a lot of buttons to get it to respond to something. It landed with the gear down, otherwise the camera/gimbal would have been worse off.

 

[lumalab]

Thanks for your input your everyone, if anything an expensive lesson as been learned...

 

[S White]

In the pilot world that is called 'Get Home-itist'. More than once I have had to make a bummer decision against my client's wish. But in the long haul they now recognize my judgement to protect equipment and people.

 

[Dobmatt]

Thanks for your input your everyone, if anything an expensive lesson as been learned...

OK, so what is the outcome of your post? Do we know something beyond speculations? Did we learn something from your unfortunate accident? Have you been able to analyze the flight log data?

 

[lumalab]

I was not able to retrieve the DAT file prior to sending it to my local DJI repair shop. Based on the comments here my conclusion is the controller was working but the rotors were stuck; first in the upward direction, preventing descent, and finally in the downward direction. It did not "fall" due to loss of power, rather it was descending rapidly (at 9kph according to the flight log). The landing gear was down, so Obstacle Avoidance was disable. A frozen rotor the most likely cause.

My take aways:
1.Clouds are wet
2. Ice is cold
3. The inspire is not amphibious
4. 8k is a lot to loose on a horse race

 

[Dobmatt]

I was not able to retrieve the DAT file prior to sending it to my local DJI repair shop. Based on the comments here my conclusion is the controller was working but the rotors were stuck; first in the upward direction, preventing descent, and finally in the downward direction. It did not "fall" due to loss of power, rather it was descending rapidly (at 9kph according to the flight log). The landing gear was down, so Obstacle Avoidance was disable. A frozen rotor the most likely cause.

My take aways:
1.Clouds are wet
2. Ice is cold
3. The inspire is not amphibious
4. 8k is a lot to loose on a horse race

Thank you for your reply, but ... what do you call a "rotor"? The one and only part which may cause such behaviour is a malfunctioning controller stick ...