Help - I lost my Mavic Mini

[cizo]

Hello people.

My name is Cizo and I'm from Brazil.

In a Facebook group in Brazil, we have several cases of Mavic Minis that fell or were lost. The famous fly away. And I was one of the victims.

I lost my Mavic Mini with less than a week of use. It was my second flight of the day. It was the second time I was using the drone. I have invoice, device approved and purchased in Brazil (Free Drone). I already have some experience, I had Phantom 3, Phantom 4 and Mavic Air. I never had any problems or incidents with any of them. He used the device with an iPhone XS Max.

As soon as I opened the box I made all the necessary updates. I calibrated the drone. The control was loaded. The drone with about 40% battery.

On February 25, he was in Ilhabela-SP. (Brazil). On a beach called Skull Beach. He used the device normally. If I'm not mistaken, before he took off, he asked to calibrate the device. But I don't remember if it was specifically on that beach or another one before. The day he fell, he was bringing him to the sand, when less than 20 meters from where I was he stopped and "CONTROL DISCONNECTED" appeared. I hadn't let go of the cable and I hadn't turned off the control either. Before I did anything, he headed back toward the sea in a downward motion, falling into the water.

In the video you can see how close I was. If he fell straight, he would fall on the sand. It turns out that as soon as he disconnected he stopped and headed towards the water.

I ran and jumped into the water to get it, but I couldn't. I still spent a long time looking with the boat I was in, I dived with a mask, but I didn't find it at all. It does not appear in the video, but the sea was full of waves.

I lost 5 days of photos and videos. And it made me very upset. It was not negligence, malpractice or recklessness. I didn't really understand what happened. The device when it fell was 4 days old. 256gb memory card.

I already wrote for DJI. I sent my documents and the flight log. As the drone fell into the sea, and I was unable to catch it, they are making it difficult. DJI's service is terrible. I'm really scared.

If someone has the expertise and patience to help me, I am sharing my flight data. I am very grateful if anyone can give me guidance on what I could write in my defense.

This is my flight log.

https://app.airdata.com/share/wRNkuL

Thank you very much if you can help me.

 

[Thomas B]

Sorry to hear about your loss. It will be of use to see the experts, like @sar104 and others, analyze your data.
I did notice in the logs you posted in the AirData link that you took off with only 40% battery remaining. Feel it’s imperative to note for new pilots that this is not a good idea, especially over water.
Hopefully DJI will offer someone discount you can use in replacing your drone.

 

[cizo]

Thank you for the answer.

I have experience, I am not a new pilot. I used the Phantom 3, 4 and the mini for many years. The battery was 40% because it had already used the drone on another beach. It had 14 satellites. The control was at 100% signal. I had already calibrated the drone. He had set up return-to-home. It wasn't windy. The drone lost its signal on the controller when it was less than 20 meters from me.

So I am absolutely sure that I did nothing wrong. I followed all the recommendations. And when he lost the signal he was in the sand, he was not in the water.

 

[sar104]

Nothing definitive because the log simply stops, but that is suggestive of a battery disconnect, which hasn't been a common problem with the Mini. The end of the log occurs just after a brief full forwards elevator followed by rapid centering, which caused a rapid pitch excursion. That's the typical precursor to a battery connection problem since it wags the aircraft's tail.



I don't have a Mini so I can't comment on how the battery is secured or how it might shake loose. Perhaps others can comment.

 

[cizo]

My friend @sar104 or any other experienced user

If you need any information I am available. If you can help me I appreciate it too much.

 

[cizo]

Nothing definitive because the log simply stops, but that is suggestive of a battery disconnect, which hasn't been a common problem with the Mini. The end of the log occurs just after a brief full forwards elevator followed by rapid centering, which caused a rapid pitch excursion. That's the typical precursor to a battery connection problem since it wags the aircraft's tail.

View attachment 95796

I don't have a Mini so I can't comment on how the battery is secured or how it might shake loose. Perhaps others can comment.

Thank you.

In your opinion, is this a problem with the drone? Did I have any responsibility?

 

[sar104]

My friend @sar104 or any other experienced user

If you need any information I am available. If you can help me I appreciate it too much.

See if you can find the mobile device DAT file ending FLY024.DAT - that's worth a quick look to see if there are any clues in the event stream.

 

[sar104]

Thank you.

In your opinion, is this a problem with the drone? Did I have any responsibility?

I don't really have enough information to give a definitive answer at this point. If the battery was not properly latched then that would be pilot error unless there is a fault with the latching mechanism.

 

[cizo]

Just a detail. He didn't fall immediately. If the battery had detached itself from the drone, I believe it would fall straight to the ground. What happened was that the drone continued to function alone. The control disconnected, he went towards the sea and gradually fell. It wasn't fast and it wasn't slow either. It took about 20 seconds to fall into the water.

 

[cizo]

See if you can find the mobile device DAT file ending FLY024.DAT - that's worth a quick look to see if there are any clues in the event stream.

I'm going to look for that file now.

Thank you very much for your time and patience.

 

[cizo]

See if you can find the mobile device DAT file ending FLY024.DAT - that's worth a quick look to see if there are any clues in the event stream.

There is no FLY024.DAT file in the application. I did a search for my mac and didn't find it. The folders I have available are these. I've looked at all of them.

 

[slup]

Nothing definitive because the log simply stops, but that is suggestive of a battery disconnect, which hasn't been a common problem with the Mini. The end of the log occurs just after a brief full forwards elevator followed by rapid centering, which caused a rapid pitch excursion. That's the typical precursor to a battery connection problem since it wags the aircraft's tail.

View attachment 95796

I don't have a Mini so I can't comment on how the battery is secured or how it might shake loose. Perhaps others can comment.

I don't know ... but doesn't this again look like a Mini suddenly losing propulsion in the end? Just being just over the water it would be fatal, with an immediate bath cutting all power/connection.

Let's see if the DAT can be found.

@cizo , the DAT log is in your mobile device you flew with ... Internal memory/DJI Fly/FlightRecords/MCDatFlightRecords in there you have a log ending with FLY024.DAT.
Retrieve it & post it here.

 

[sar104]

Just a detail. He didn't fall immediately. If the battery had detached itself from the drone, I believe it would fall straight to the ground. What happened was that the drone continued to function alone. The control disconnected, he went towards the sea and gradually fell. It wasn't fast and it wasn't slow either. It took about 20 seconds to fall into the water.

Okay - so that's what happens when I don't take enough time to look at all the data. You are correct - the log includes the descent to the water, and the log ends due to splashdown.



This is another uncommanded descent by a Mavic Mini. You need to point that out to DJI - they have been replacing these under warranty for this exact problem.

 

[sar104]

I don't know ... but doesn't this again look like a Mini suddenly losing propulsion in the end? Just being just over the water it would be fatal, with an immediate bath cutting all power/connection.

Let's see if the DAT can be found.

@cizo , the DAT log is in your mobile device you flew with ... Internal memory/DJI Fly/FlightRecords/MCDatFlightRecords in there you have a log ending with FLY024.DAT.
Retrieve it & post it here.

View attachment 95802

Yes - that's exactly what it was. I was in too much of a hurry earlier, and didn't even look at the vertical data.

 

[cizo]

I don't know ... but doesn't this again look like a Mini suddenly losing propulsion in the end? Just being just over the water it would be fatal, with an immediate bath cutting all power/connection.

Let's see if the DAT can be found.

@cizo , the DAT log is in your mobile device you flew with ... Internal memory/DJI Fly/FlightRecords/MCDatFlightRecords in there you have a log ending with FLY024.DAT.
Retrieve it & post it here.

View attachment 95802

Thank you so much for your help.

I followed your guidance. This folder is empty. I made other flights the same day it crashed and a few other flights the day before. And there is nothing recorded in that folder. Zero.

 

[cizo]

Okay - so that's what happens when I don't take enough time to look at all the data. You are correct - the log includes the descent to the water, and the log ends due to splashdown.

View attachment 95804

This is another uncommanded descent by a Mavic Mini. You need to point that out to DJI - they have been replacing these under warranty for this exact problem.

My God. How good to hear that. Thank you very much. I don't know how to thank you.

Sorry to ask you this, but could I write specifically what I have to write for DJI? The parameters and technical data of this request. I'm sorry for asking you that.

 

[MAvic_South_Oz]

Thank you so much for your help.

I followed your guidance. This folder is empty. I made other flights the same day it crashed and a few other flights the day before. And there is nothing recorded in that folder. Zero.

Still, it looks like the .dat is not needed, as noted by @slup and confirmed by @sar104 this is a classic mini problem and DJI should replace it for you.
Good luck with a simple admission from them, and replacement.

 

[slup]

Thank you so much for your help.

I followed your guidance. This folder is empty. I made other flights the same day it crashed and a few other flights the day before. And there is nothing recorded in that folder. Zero.

Yeah ... that the DAT is missing from Mini's isn't unusual unfortunately. In this case though, you should bring this "Uncommanded descent" up with DJI ... they have been sending out new drones pretty much without any hassle in relation to events like this.

 

[cizo]

Still, it looks like the .dat is not needed, as noted by @slup and confirmed by @sar104 this is a classic mini problem and DJI should replace it for you.
Good luck with a simple admission from them, and replacement.

You have no idea how happy I am to hear that. From the bottom of my heart. I was absolutely sure that I had done nothing wrong. Thank you very much to all of you for your help and patience.

I was very sad to lose the drone and especially the photos and videos I had taken with my wife. It was a trip planned for months to a city I frequented as a child, I have many memories of Ilhabela. At least I don't feel guilty anymore, even without guilt.

 

[cizo]

Yeah ... that the DAT is missing from Mini's isn't unusual unfortunately. In this case though, you should bring this "Uncommanded descent" up with DJI ... they have been sending out new drones pretty much without any hassle in relation to events like this.

I'm very happy. Really. Thank you.