Help - I lost my Mavic Mini

[sar104]

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.

You can use the graphs in this thread if you want to, but basically just point out to DJI that the flight log unambiguously shows the aircraft descending into the water with no down throttle applied, and that you are aware that they have seen numerous cases of this happening and replaced the aircraft.

 

[cizo]

I didn't have to do anything at all. DJI just confirmed that it was a problem with the drone and will offer me a new one. I just sent the flight log, nothing more.

Thank you very much to all of you. Thank you very, very much. You were incredible.

 

[lannes]

Another bit of advice is not to use such a big micro SD card, it makes you lazy to transfer off the valuable photos and videos to your PC.
When you have a flyaway you loose a lot of data like you have done.

Use a smaller capacity card, they are cheaper and will force you to copy over all the important data more often.
64gb will record up to 3hrs of video.

 

[Chanctonbury]

I didn't have to do anything at all. DJI just confirmed that it was a problem with the drone and will offer me a new one. I just sent the flight log, nothing more.

That is an impressive result from DJI - excellent.

Another bit of advice is not to use such a big micro SD card, it makes you lazy to transfer off the valuable photos and videos to your PC.
When you have a flyaway you loose a lot of data like you have done.

This is a good point and not one that I considered when I bought my 128GB SD Card - Doh!

 

[Rockycat]

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.

sar104, you are the MAN! I can't thank you enough for helping out this drone community.
I enjoy tremendously how you study the facts and render an appropriate conclusion.
Well done!

 

[mariof608]

It seem that the battery in your MM got disconnected for some reason, this could had happened while in transport before taking off the battery was already loose. It is crucial before flying that you go through a flight check to ensure all is well. Before I fly I check to ensure the battery is snapped in correctly, I always remove the battery and placed it in when I am about to fly this ensure the battery is snapped in place and the door is closed tight. I really believe your battery came unsnapped when your MM came to a sudden stop that why your MM fell straight down.

 

[slup]

It seem that the battery in your MM got disconnected for some reason, this could had happened while in transport before taking off the battery was already loose. It is crucial before flying that you go through a flight check to ensure all is well. Before I fly I check to ensure the battery is snapped in correctly, I always remove the battery and placed it in when I am about to fly this ensure the battery is snapped in place and the door is closed tight. I really believe your battery came unsnapped when your MM came to a sudden stop that why your MM fell straight down.

No that's not what happened, this was the famous "Mini uncommanded descent" DJI have also taken the blame & offered the OP a new drone ... see post 12 & 13

 

[silverdragon]

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.

Is it possible to make notations on the lines of representation? For example: at one of the spikes and a brief note of want it meant or means. I'm curious and I'm sure many others also. If it's to time consuming I do understand. Maybe notate at areas of concern. I'm sure it would give many including myself a better understanding of what some of the meanings of a line on the graph. Thanks

 

[sar104]

Is it possible to make notations on the lines of representation? For example: at one of the spikes and a brief note of want it meant or means. I'm curious and I'm sure many others also. If it's to time consuming I do understand. Maybe notate at areas of concern. I'm sure it would give many including myself a better understanding of what some of the meanings of a line on the graph. Thanks

I try to annotate the graphs when the interpretation is not straightforward, but if that is helpful more generally then I'll add notes more often. Thanks for the suggestion.

 

[cizo]

Another bit of advice is not to use such a big micro SD card, it makes you lazy to transfer off the valuable photos and videos to your PC.
When you have a flyaway you loose a lot of data like you have done.

Use a smaller capacity card, they are cheaper and will force you to copy over all the important data more often.
64gb will record up to 3hrs of video.

Truth. There was no thinking about it.

sar104, you are the MAN! I can't thank you enough for helping out this drone community.
I enjoy tremendously how you study the facts and render an appropriate conclusion.
Well done!

Perfect. Exactly. Helped me a lot.

It seem that the battery in your MM got disconnected for some reason, this could had happened while in transport before taking off the battery was already loose. It is crucial before flying that you go through a flight check to ensure all is well. Before I fly I check to ensure the battery is snapped in correctly, I always remove the battery and placed it in when I am about to fly this ensure the battery is snapped in place and the door is closed tight. I really believe your battery came unsnapped when your MM came to a sudden stop that why your MM fell straight down.

My drone didn't fall straight. If the battery had been released from the drone, it would immediately fall, straight to the ground. It would be gravity at work. But I lost the signal and it continued to work on its own, for about 20 seconds. He started to move towards the water and gradually fell. So the problem was not that the battery fell.

No that's not what happened, this was the famous "Mini uncommanded descent" DJI have also taken the blame & offered the OP a new drone ... see post 12 & 13

Exactly.

 

[CallSignShadow]

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.

In the 100+ instances where Minis are lost DJI will give 10% off, they are brutal that way. YMMV

 

[sar104]

In the 100+ instances where Minis are lost DJI will give 10% off, they are brutal that way. YMMV

That's demonstrably not the case. Especially for losses due to this particular issue, which has become rather widespread, DJI has been replacing Minis with few questions asked.

 

[Prismatic]

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.

Like you, I use a large SD card (128GB) in my Air. But I carry a laptop with me when I travel, and I download the drone files each evening to two redundant USB thumb drives. At most, a disaster will cost me the drone plus that day's images; that's bad enough, but at least not the whole trip!

 

[cizo]

Like you, I use a large SD card (128GB) in my Air. But I carry a laptop with me when I travel, and I download the drone files each evening to two redundant USB thumb drives. At most, a disaster will cost me the drone plus that day's images; that's bad enough, but at least not the whole trip!

Unfortunately, I hadn't taken my macbook on the trip. The day I lost it, I had left the boat early, made a flight in a natural saltwater pool, another flight in a cachoreia, another flight on a beach. On the second beach I used the drone it was the moment he fell into the water. He had taken beautiful pictures. The city of Ilhabela is an island, with crystal clear water. A wonderful place. The skull beach, where my drone lived on the bottom of the sea, can only be reached by boat. A virgin beach. More than 2 hours of navigation.

Another detail that I never imagined could happen. I always flew with extreme attention. I never had any risky situations in the other drones that I had. And unfortunately I was not prepared. My idea was to unload the memory card only when I got home.

 

[Prismatic]

... I always flew with extreme attention. I never had any risky situations in the other drones that I had. And unfortunately I was not prepared. My idea was to unload the memory card only when I got home.

I am so sorry for you, and more for the irreplaceable photos and videos than for the very-replaceable Mini. This model often commits suicide through no fault of the pilot, and no one is prepared for that. From what I read here, the Mini is not reliable; there's a high probability of disaster with every flight.

I'll make a couple of observations about this flight, but neither has any bearing on what happened:

1. You took off with 40% battery. I can see you had a short flight in mind, but even so, it's generally considered unwise to launch with a partially discharged battery. The displayed battery value is only an estimate, and there may be less capacity remaining than you think.
2. Your RTH altitude was unnecessarily high. If there had been an offshore breeze and the drone went into RTH, it would have ascended to where the wind is very often much, much stronger than it is down on the ground. Such a high RTH setting invites a "blow-away", which is the other main reason that Minis go missing. As a rule, set your RTH at the minimum safe altitude, where "safe" is determined by the highest object that could cause trouble. For example, flying from the beach out over the sea, you could safely set RTH at 10m, assuming there are no tall ships, islands, or headlands that might get between the drone and the home point.

Again, neither seems to have been a factor in what happened, and I only mention them for future reference.

If I could console you, I'd raise a glass and say, "Here's to your drone! But what was it thinking? You told it "fly home." Instead, it went drinking!"?

 

[cizo]

I am so sorry for you, and more for the irreplaceable photos and videos than for the very-replaceable Mini. This model often commits suicide through no fault of the pilot, and no one is prepared for that. From what I read here, the Mini is not reliable; there's a high probability of disaster with every flight.

I'll make a couple of observations about this flight, but neither has any bearing on what happened:

1. You took off with 40% battery. I can see you had a short flight in mind, but even so, it's generally considered unwise to launch with a partially discharged battery. The displayed battery value is only an estimate, and there may be less capacity remaining than you think.
2. Your RTH altitude was unnecessarily high. If there had been an offshore breeze and the drone went into RTH, it would have ascended to where the wind is very often much, much stronger than it is down on the ground. Such a high RTH setting invites a "blow-away", which is the other main reason that Minis go missing. As a rule, set your RTH at the minimum safe altitude, where "safe" is determined by the highest object that could cause trouble. For example, flying from the beach out over the sea, you could safely set RTH at 10m, assuming there are no tall ships, islands, or headlands that might get between the drone and the home point.

Again, neither seems to have been a factor in what happened, and I only mention them for future reference.

If I could console you, I'd raise a glass and say, "Here's to your drone! But what was it thinking? You told it "fly home." Instead, it went drinking!"?

I ended up keeping the factory settings. I don't particularly like to touch anything. I have a more conservative profile, always thinking about security. I will follow your directions on my new aircraft.

The battery at 40% I didn't end up finding a problem. And my intention was to make a video of the drone entering the beach, at very low height. And it was exactly the video movement I was doing before it fell. Where he disconnected, he would take some pictures of the sand and drop the drone. And I would go to the next beach and use a new battery.

It is very sad to hear that the mini is not reliable. In a group of DJI MAVIC MINI do Brasil, we have 1500 subscribers. And at least 20 cases of drones that crashed. All reporting some kind of fly away. A lot of people complaining. And I'm very concerned about that.

I thank you for the warmth and friendliness.

 

[Prismatic]

... It is very sad to hear that the mini is not reliable. In a group of DJI MAVIC MINI do Brasil, we have 1500 subscribers. And at least 20 cases of drones that crashed. All reporting some kind of fly away. A lot of people complaining. And I'm very concerned about that.

I thank you for the warmth and friendliness.

A failure rate of 1% or 2% is no surprise. Actually, I wouldn't be terribly surprised if the true rate of fatal malfunction is much higher. Whatever the problem is, what's to say they don't all have it? At this point, I personally regard every Mini as (possibly?) a ticking time bomb.
And I hardly need tell you that if your Brazilian MM group has anyone as skilled as some our wizards here, they are very lucky indeed.?‍

Mavic Mini - Uncommanded Descents

Reference the numerous complaints about uncommanded descents/crashes. I had this problem as well where my mini would start a descent and not respond to any control input. Some times it would stop short of hitting the ground and I would regain control, but there were also a few hard landings...

mavicpilots.com

 

[Capt KO]

You may get lucky and get a better drone then you just lost. Seems the replacements may have a couple Improvement. Will Wait and see. Just be careful over water as the bottom sensors don't seem to work well when too low. You may still get uncommanded descent. Good luck with your new Mini, hopefully

 

[Prismatic]

You may get lucky and get a better drone then you just lost. Seems the replacements may have a couple Improvement. Will Wait and see. Just be careful over water as the bottom sensors don't seem to work well when too low. You may still get uncommanded descent. Good luck with your new Mini, hopefully

I hope you're right!

 

[sar104]

You may get lucky and get a better drone then you just lost. Seems the replacements may have a couple Improvement. Will Wait and see. Just be careful over water as the bottom sensors don't seem to work well when too low. You may still get uncommanded descent. Good luck with your new Mini, hopefully

I've seen no actual evidence of significant sensor issues, but the propulsion problems are real.