Another Mavic Mini needing your help please

[HutchHavic]

After losing my Mavic Mini yesterday, blown away, can I please ask for some expert analysis on what it’s final moments were (after it just abruptly lost transmission), and possibly where it could have ended up?

And please before I get lectures on flying conditions and how I made all the errors, please consider that I understand how supposedly I am to blame, my wife let’s me know, my Mavic pro owning friend let’s me know, so I get that part. $800 flying away in less than a week will teach me that.

So, from the.txt file hopefully one can see (yes, where I went wrong) but also some of the strange events throughout the flight that simply put, made it a lot harder to get and then keep control.
note: I also chased the drone; my friend quickly got his car and we went after it. At the final notification, I was within 200 metres of the drone when all comms just went dead.
The real question for me is, I was on scene at the last known location within 2 minutes, why could I not track onto it when it landed. Why does it give the last known location (at 7% battery left) at 40m in the air? Is It weird that it suddenly drops out so I end up looking in the wrong area for 30 minutes before realising that this is not actually where it is, but anywhere downwind.

also one last thing; after about 15 minutes of looking at the last known location point, I briefly, very briefly reconnected with the drone for about 2 seconds and saw from the camera that it appeared to be upside down and possibly near a car (blurred vision). Which makes sense of it being downwind amongst houses. But it disconnected so abruptly, as if it hits a tree, but then the reconnection shows it was still alive, so if it can reconnect, why can’t the gps be updated to take me to it? Seams so simple, but so many pilots seam to be losing drones when a gps should be guiding searchers to to its last known “landed” position.

Thankyou in adVance and I hope you guys can shed some light on this frustrating situation.

ps, I’m aware of the wind thing, I’ve told myself that a million times in the last 24 hours, seriously.

 

[old man mavic]

welcome to the forum
sorry for the loss of your drone i am sure one of our expert log readers will help you out soon and maybe you will recover it

 

[Thomas B]

Welcome to the forum from the deserts of Arizona! Enjoy.
One of the resident sages like @sar104 or @slup should chime in to help your analysis.

 

[HutchHavic]

Thanks very much for the welcome, it hasn’t rained and I hope there is a chance to find it, was so impressed with the mini and I’m lost without it????

 

[slup]

1... and possibly where it could have ended up?
2... please before I get lectures ... my wife let’s me know
3... I was on scene at the last known location within 2 minutes, why could I not track onto it when it landed
3... Why does it give the last known location (at 7% battery left) at 40m in the air?
3... Is It weird that it suddenly drops out so I end up looking in the wrong area...
3... I briefly, very briefly reconnected with the drone for about 2 seconds ...so if it can reconnect, why can’t the gps be updated to take me to it?

I will directly start up saying that @sar104 is the best to pinpoint the location with all his wind profiles & Igor Pro sw ... that settles #1 (even though the very varying heading speed (dark green in chart) might make it a bit tricky).

And as requested #2 we skip

But for #3 ...

One thing that's very important to understand regarding the Mini's connection method (enhanced WiFi) is that it quickly degrades when going out of unobstructed line of sight or/and are effected by WiFi interference.

As shown i below chart you had a lot of disconnects (light green)(chart only shows the very end of the flight though...), the altitude (red) in the end were approx 40m & this on a distance (red) to HP of 1973m. At that distance & height it's not surprising that you lose the connection completely. The "landbattery" level (yellowish) at that point were defined to 6%, so just one % later the Mini started to auto land being on 7% (blue) at the time. So in case of a disconnect the log ends if the signal isn't picked up again. The reason for not updating the "find my drone" position when the RC briefly connects again is probably due to not having a proper position fix laying upside down. So with all this, the position in your app is the last known/reported ... then at 40m altitude soon starting to land.

When you was on the scene later on the Mini had probably already touched down ... then it's a lot of thing's in between your RC & the AC, you were just lucky to have a short connect.



The wind speeds & directions for the record ...

 

[sar104]

It didn't go very far - it was only around 10 seconds from commencing autolanding at the end of the flight record.



Applying the usual method with a 3 m/s descent and continued drift, since the wind speed looks to have been quite consistent with height, that puts it 2115 m out at landing:



Taking a closer look at the landing area:



I would take a look in an area around the pin - it should be good to within 30 meters or so. Hopefully it didn't come down in the road.

 

[slup]

And as the OP said that it looked like laying beside a car when the connection shortly reestablished ... perhaps extend the search area to the other side of the road.

 

[sar104]

And as the OP said that it looked like laying beside a car when the connection shortly reestablished ... perhaps extend the search area to the other side of the road.

View attachment 95643

Good point - I missed that in the original post. That suggests that it did reach the road.

 

[HutchHavic]

Thank you very much guys, it’s certainly narrowed the search zone (which I’m at right now.) I have asked one lady in the house to the left extreme of the red line but to no avail. One question before continuing the search (fruitless so far but I have all day). Given that the last brief connect appeared to have the drone upside down, and I was almost exactly at the gps coordinate of the last known position, what sort of range would one have to be to the unit to get an actual connection (albeit brief, but solid enough to give a picture for all of two to three seconds) long enough for me to show my friend before it dropped out. 3 seconds. The ground is slightly higher than the road and downwind search area, maybe 1m to 1.5m rise..? Thanks again

And sorry.. one more; is it definitely going to auto land or is it possible it would attempt to return to home?

 

[sar104]

Thank you very much guys, it’s certainly narrowed the search zone (which I’m at right now.) I have asked one lady in the house to the left extreme of the red line but to no avail. One question before continuing the search (fruitless so far but I have all day). Given that the last brief connect appeared to have the drone upside down, and I was almost exactly at the gps coordinate of the last known position, what sort of range would one have to be to the unit to get an actual connection (albeit brief, but solid enough to give a picture for all of two to three seconds) long enough for me to show my friend before it dropped out. 3 seconds. The ground is slightly higher than the road and downwind search area, maybe 1m to 1.5m rise..? Thanks again

And sorry.. one more; is it definitely going to auto land or is it possible it would attempt to return to home?

After overlooking your original comment about the aircraft reconnecting briefly, I also overlooked the fact that the mobile device DAT file will contain telemetry from that reconnect, likely including the GPS coordinates. Can you see if you can find the DAT file with a name ending FLY026.DAT, and post that?

 

[HutchHavic]

I hate to say but that folder is empty? Is it true that DJI has those files removed from your device after syncing? I thought I read that somewhere for the mini?

 

[sar104]

I hate to say but that folder is empty? Is it true that DJI has those files removed from your device after syncing? I thought I read that somewhere for the mini?

Unfortunately that is correct. I guess that would have been too easy.

 

[HutchHavic]

I’m crying here, I reckon I’ve spent at least 10 hours in the search zone, I’ve knocked on all the doors on the other side of the road but no one has seen nor heard anything. I’m waiting to hear back from DJI but it s been a while and I think I know the “pilot error” verdict will be the result. It’s sort of annoying that the DAT file in all likelihood could solve this problem, and it is DJI who can access it, but with a lot of claims from people in my situation, the process is slowed, and time to find it and suitable conditions will sooner or later run out. Best I talk to them as a last ditch attempt. Thankyou all again and i’ll post with any results ?

 

[lannes]

What color was the car, was it on a drive way or grass ?

Did the drone have your contact details on it ?

Maybe you can do a letter box drop offering a reward and watch out on gumtree

 

[HutchHavic]

A very good idea and have started letterbox drop already. Have been on the line to DJI and have managed to get the DAT folder onto my PC but alas, it still has not files in it. Does anyone know if there is something there, it’s just super hidden, or do they actually get removed upon sync, therefore DJI has them, they’re just very cagey about using them to help?
Anyway, looks like a letterbox drop is my best bet.
There was 21 satellites for that flight I believe, and here I am canvassing the suburb in the vain hope I get a lucky break (which I have offered a $50 reward for).
I was so close, but I’m almost done, will wait for that phone to ring, and hope that all my efforts are not for nothing. Just maybe, please DJI, see it in your heart to help me here, I don’t want to go from the happiest newbie pilot to hanging up my wings in lest than a week. I just can’t justify getting back into the game again... and did I mention my wife and her take on the matter. The headline would read;
“Husband crucified by angry wife after drone flyway, left to rot in field at last known location”
“Let that be a lesson to other drone wannabe husbands - get ya head out of the clouds!” Says irate wife as she and the angry mob from Wives Against Drones (WAD) nail his hands and feet to the cross and hoist him aloft.
???

 

[lannes]

A very good idea and have started letterbox drop already. Have been on the line to DJI and have managed to get the DAT folder onto my PC but alas, it still has not files in it. Does anyone know if there is something there, it’s just super hidden, or do they actually get removed upon sync, therefore DJI has them, they’re just very cagey about using them to help?
Anyway, looks like a letterbox drop is my best bet.
There was 21 satellites for that flight I believe, and here I am canvassing the suburb in the vain hope I get a lucky break (which I have offered a $50 reward for).
I was so close, but I’m almost done, will wait for that phone to ring, and hope that all my efforts are not for nothing. Just maybe, please DJI, see it in your heart to help me here, I don’t want to go from the happiest newbie pilot to hanging up my wings in lest than a week. I just can’t justify getting back into the game again... and did I mention my wife and her take on the matter. The headline would read;
“Husband crucified by angry wife after drone flyway, left to rot in field at last known location”
“Let that be a lesson to other drone wannabe husbands - get ya head out of the clouds!” Says irate wife as she and the angry mob from Wives Against Drones (WAD) nail his hands and feet to the cross and hoist him aloft.
???

What make you think it landed upside down near a car, you probably have an idea what it looks like e.g. wheel design, body color, asphalt or grassed area etc.
I'd go back this evening and try to pin point it in the street, people would have been back from work by then and parking their cars in the street and on driveways etc.

Do you have cache video ?

 

[xspwhite]

A very good idea and have started letterbox drop already. Have been on the line to DJI and have managed to get the DAT folder onto my PC but alas, it still has not files in it. Does anyone know if there is something there, it’s just super hidden, or do they actually get removed upon sync, therefore DJI has them, they’re just very cagey about using them to help?
Anyway, looks like a letterbox drop is my best bet.
There was 21 satellites for that flight I believe, and here I am canvassing the suburb in the vain hope I get a lucky break (which I have offered a $50 reward for).
I was so close, but I’m almost done, will wait for that phone to ring, and hope that all my efforts are not for nothing. Just maybe, please DJI, see it in your heart to help me here, I don’t want to go from the happiest newbie pilot to hanging up my wings in lest than a week. I just can’t justify getting back into the game again... and did I mention my wife and her take on the matter. The headline would read;
“Husband crucified by angry wife after drone flyway, left to rot in field at last known location”
“Let that be a lesson to other drone wannabe husbands - get ya head out of the clouds!” Says irate wife as she and the angry mob from Wives Against Drones (WAD) nail his hands and feet to the cross and hoist him aloft.
???

Did you check that patch of trees that sar pointed out on the map? If the drone was indeed upside down, then it could very well be hanging from a tree branch.

 

[HutchHavic]

Excellent idea thanks Iannes, yes during the day there’s a few red cars around in driveways but I notice that they’re often people visiting so it confuses the issue. Much better use of time a bit later on, plus people are home for a door knock and not so hot.
I’ll give it one last hurrah tonight and then back to reality tomorrow with work.

ps, to answer the question about the vision from that last connection.
the last known position is fair and square out in a clear paddock. At that point, telemetry said it was at about 40m altitude...

(Does anyone know if that means above the original starting/home point or above the ground where it is/was?) —- (confusing because the starting point is 60m above sea level and the ground height at the last known location is approx. 23m above sea level. So if it’s the height above the starting point (so 60m asl + 40m as indicated altitude at last known location, does that then put it at 100m asl?)

Can I please narrow down one or two last questions that will hopefully help me when I head back this arvo/tonight.

1. The manual says for the Mini to be within 1.5m from the RC when linking the unit. Considering the drone is upright (as opposed to upside down) and you attempt the connection, what would be the furthest distance one could possibly hope to get away from the unit at which the connection will not work?
Simply (maybe someone could test.) what distance will it link at unobstructed? What distance does it generally fail?
I assume there will be variables... when I last got connection, I was standing at the last known location, facing down wind (to the north west).
With this in mind, hopefully I can narrow the range drastically. If it’s 50m, that is awesome, it was within roughly 50m at that last contact. If for some reason it could still be 500m (even though the manual says 1.5m) then I’m stuck looking in the suburbs.

I’m trying to eliminate whether the last picture of something definitely red, was perhaps a car door, or am I dreaming and it was just a pomegranate on a tree. Because there is a pomegranate tree within 50m of the last known gps coordinate. Trust me I’ve looked there, but if anyone can definitively give an initial connection range for sure, it would certainly help.
Sincerely and greatly appreciated, I will throw everything into this, I really want to find the mini, obviously to get back flying, but to also clear up a whole pile of questions that arise from this situation.
Ie. last known gps vs. downwind trajectories vs starting altitudes vs brief last minute connections vs. what I should have done with that connection. etc. etc

Thankyou again, cheers appreciate all this

 

[HutchHavic]

Have looked and looked in the new search point for 2 hours this morning + an extended area to about 100m all around that point as well as talking to four neighbours in houses across the road (no joy at all,not even a brief noise someone may have heard) to letterbox dropping neighbours not home and about to letterbox drop in the street one street behind.

 

[HutchHavic]

Sorry no cache video (I’m spewing) because phone was filling up and then all data\telemetry was freezing and no videos or telemetry anyway...