Crash data help

[Hoopster3]

Long story that I'll do my best to sum up.....

Crashed the Mavic soon after I got it. Vision sensor broken and gimbal wouldn't move the camera. Ended up sending it to Cloud City Drones after sending them pictures and receiving an estimate. They said they fixed it successfully and it passed the test flight so they were sending it back. The box came back in a less than ideal state, so I had some concerns about damage when I received it through UPS.

Took the Mavic out that night and did my normal pre-takeoff routine. Turned the controller and Mavic on a waited for some satellites to connect. Took off to hover at about 3 ft to test the gimbal and make sure it was working. That's when everything went haywire. The Mavic took off across the street and was heading toward my neighbors house. I tried to input controls to get the Mavic out of harms ways but it didn't respond. I even tried the pause button but am unsure if it was too late or not. Unfortunately the Mavic crashed into my neighbor's tree. Several rotors were broken and again the gimbal was malfunctioning and the battery was thrown out. The Mavic had never acted like this before and I was left to wonder if Cloud City Drones are responsible or if something happened in shipping or it was something I did wrong.

I emailed Cloud City Drones and they are requesting my flight log. When I connect the Mavic to my computer and use the DJI Assistant 2 it keeps saying that there are "No Flight Logs". Using the DJI Go 4 app, which I use for flights, I was able to extract some data. I used Healthydrones (formerly AirData) to create this link however I'm not sure it's what I need to send to Cloud City Drones. Can someone review the data and let me know if they see something abnormal? I'm left to figure out if it's Cloud City Drones, UPS shipping or something I did that caused the Mavic to act like it did. I have 30+ flights with the Mavic, which isn't a ton, but have never had an issue like this.

Any help would be greatly appreciated.

http://app.airdata.com/main?share=qzVCUM

 

[sar104]

That link alone is not much use, since AirData only provides a summary of the flight. You will need to post the actual log, or upload it to PhantomHelp, or enable csv download in AirData.

 

[Hoopster3]

That link alone is not much use, since AirData only provides a summary of the flight. You will need to post the actual log, or upload it to PhantomHelp, or enable csv download in AirData.

Is this more helpful- http://app.airdata.com/main?share=GzNwfo

 

[Hoopster3]

I have attached the actual flight log as well, right from the DJI Go 4 app.

 

[YngveN]

Here is your flightlog on Phantomhelp

Shows continuous compass error from 10 seconds into your flight. Did you do any compass calibration before your flight?

 

[sar104]

It was reporting compass errors continuously from 10.6 seconds onwards, which coincided with increasingly uncontrolled pitch and roll angles. Need the DAT file to see what was going on.

 

[Hoopster3]

Here is your flightlog on Phantomhelp

Shows continuous compass error from 10 seconds into your flight. Did you do any compass calibration before your flight?

I calibrated the compass before take off. Not sure why it would show that starting at 10 seconds into the flight and not at the beginning if it needed calibrated again.

 

[Hoopster3]

It was reporting compass errors continuously from 10.6 seconds onwards, which coincided with increasingly uncontrolled pitch and roll angles. Need the DAT file to see what was going on.

How do I get the DAT files? When I plug in the Mavic to the computer and use the DJI Assistant 2, it tells me there are no flight logs. Could the internal storage have been damaged in the crash?

 

[sar104]

How do I get the DAT files? When I plug in the Mavic to the computer and use the DJI Assistant 2, it tells me there are no flight logs. Could the internal storage have been damaged in the crash?

How to retrieve a .DAT

Note that the process depends on which version of Assistant you are using. If v 1.0.9 or later then the aircraft internal storage will appear on your computer as an external drive after entering flight record mode in Assistant, and then you just copy the files across without using Assistant.

 

[BudWalker]

How do I get the DAT files? When I plug in the Mavic to the computer and use the DJI Assistant 2, it tells me there are no flight logs. Could the internal storage have been damaged in the crash?

If you're on FW 01.03.1000 then the .DAT will be unavailable. If you can't retrieve the .DAT from the Mavic there is a .DAT on the tablet that can sometimes have enough good data to analyze an incident like this.

From the description this incident is almost certainly caused by ferrous material at the launch site. If you replay the flight using the Go App I believe what you'll see is that the red triangle heading indicator in the map display is pointing in the wrong direction immediately before and after launch. With these types of incidents this is the only way to know that there is a problem and a fly away is likely.

If you could tell us what the AC heading was before launch that could be compared with the .txt to determine if the FC's Yaw value was incorrect. I'd do this myself but I'm restricted to my iPad at the moment.

This incident is unrelated to the compass calibration before the flight. In fact, calibrating, or not calibrating, at any location would have had no effect on this incident.

 

[Hoopster3]

If you're on FW 01.03.1000 then the .DAT will be unavailable. If you can't retrieve the .DAT from the Mavic there is a .DAT on the tablet that can sometimes have enough good data to analyze an incident like this.

From the description this incident is almost certainly caused by ferrous material at the launch site. If you replay the flight using the Go App I believe what you'll see is that the red triangle heading indicator in the map display is pointing in the wrong direction immediately before and after launch. With these types of incidents this is the only way to know that there is a problem and a fly away is likely.

If you could tell us what the AC heading was before launch that could be compared with the .txt to determine if the FC's Yaw value was incorrect. I'd do this myself but I'm restricted to my iPad at the moment.

This incident is unrelated to the compass calibration before the flight. In fact, calibrating, or not calibrating, at any location would have had no effect on this incident.

Thank you for the response. The heading of the Mavic was East at takeoff, even though the logs show it pointing NW. I have taken off from a launch pad in my yard every time I have taken off. I guess there could be ferrous material under my lawn, but I purposefully launch from this spot as it's away from my driveway, house and any sidewalks. The driveway is the nearest to my location and is still about 20 feet away.

Do you still think that is what caused the problem? It's hard for me to imagine that after 30+ flights launching from the same site that I would have a problem on my 1st flight after receiving the Mavic back from being "fixed". I flew the Mavic at least 15 times after my 1st crash and before I sent it in to be repaired and the only thing that didn't work was gimbal moving the camera and the forward vision sensors because they were broke in the crash. I'm starting to believe that something wasn't fixed correctly or a problem occurred during shipping. Am I not thinking logically???

 

[sar104]

Thank you for the response. The heading of the Mavic was East at takeoff, even though the logs show it pointing NW. I have taken off from a launch pad in my yard every time I have taken off. I guess there could be ferrous material under my lawn, but I purposefully launch from this spot as it's away from my driveway, house and any sidewalks. The driveway is the nearest to my location and is still about 20 feet away.

Do you still think that is what caused the problem? It's hard for me to imagine that after 30+ flights launching from the same site that I would have a problem on my 1st flight after receiving the Mavic back from being "fixed". I flew the Mavic at least 15 times after my 1st crash and before I sent it in to be repaired and the only thing that didn't work was gimbal moving the camera and the forward vision sensors because they were broke in the crash. I'm starting to believe that something wasn't fixed correctly or a problem occurred during shipping. Am I not thinking logically???

As that was the first flight after you received it, it is possible that the IMU and compass might have needed calibration. The aircraft may have been exposed to strong magnetic fields in transit, for example. If you have flown from that spot without problems before then the effect of magnetic interference from ferrous materials at the launch point - the most obvious cause - becomes less likely.

 

[BudWalker]

Thank you for the response. The heading of the Mavic was East at takeoff, even though the logs show it pointing NW. I have taken off from a launch pad in my yard every time I have taken off. I guess there could be ferrous material under my lawn, but I purposefully launch from this spot as it's away from my driveway, house and any sidewalks. The driveway is the nearest to my location and is still about 20 feet away.

Do you still think that is what caused the problem? It's hard for me to imagine that after 30+ flights launching from the same site that I would have a problem on my 1st flight after receiving the Mavic back from being "fixed". I flew the Mavic at least 15 times after my 1st crash and before I sent it in to be repaired and the only thing that didn't work was gimbal moving the camera and the forward vision sensors because they were broke in the crash. I'm starting to believe that something wasn't fixed correctly or a problem occurred during shipping. Am I not thinking logically???

Its hard to imagine in what way a compass could be broken and exhibit a 135 degrees error. It just wouldn't work at all.

You could try to locate the cause by using the Mavic. This requires that the Mavic be placed in a suspect location and then waiting at least a minute to see if the red triangle heading indicator is incorrect.

Another scenario to think about is if the Mavic is powered up in geomagneticaly distorted spot (like a metal picnic table, etc.) but then moved to an OK spot for launch. The incorrect magnetometers are used to initialize the Yaw value but after that it's mostly the IMU that's used to update the Yaw value. Magnetometer data is used but only at a low gain. If launch occurs soon after it's placed in the OK spot then Yaw will not have been adjusted yet to the correct value.