LOST DRONE. Need advise to locate it

[dedomocho8]

Ok guys a newby here needs advises

First time flying my dji mini 2, I LOST IT.
Here is what happened:
I was flying it around at an altitude of 105m about 800m from me and battery popped up low. The RTH FUNCTION automatically started but nearly 10 seconds later it lost connection completely.
It never arrived home and been looking for it all day with no luck. The find my drone function shows it's at a school patio nearby, but I went there and didn't find it, so idk how accurate it is. Also looked for the trips data and last thing recorded was there. Questions:

1)What else could i try?
2)When the battery dies does the drone just drop from where it is, or safely lands?
3) what are te chances it landed in a tree? (I mean does it recognize things above the ground as obstacles?)
4) if someone happens to plug it in and recharge it, will "find my drone" find it or the controlled needs to be connected?
5)Could it have lost signal but still keep returning home so it got stuck on the way back?
The area is a suburb un a city, no high buildings or anything but lots of houses.

Thank youuuu

 

[sar104]

I suggest that you post the flight log.

 

[MAvic_South_Oz]

Welcome to the forum.
Yes, a flight log as soon as possible will give you the best chance at finding it.
Before the weather or someone else happens along.

Section 3 to get your flight log txt.

Mavic Flight Log Retrieval and Analysis Guide

With the introduction of the Mavic Mini there has been a noticeable uptick in the number of posts requesting help with lost or crashed aircraft. While there is plenty of help and advice available on this forum, and detailed guidance and options on several other websites, I thought that perhaps a...

mavicpilots.com

 

[dedomocho8]

I suggest that you post the flight log.

Post it to where? Here? sorry first time using a drone, i don't even know how to do it.

 

[sar104]

Post it to where? Here? sorry first time using a drone, i don't even know how to do it.

Post it here, and someone will take a look to see if there are any further clues to where it ended up. There are instructions on retrieving it in the links above. Or you can visit AirData or PhantomHelp for instructions.

 

[dedomocho8]

I suggest that you post the flight log.

Welcome to the forum.
Yes, a flight log as soon as possible will give you the best chance at finding it.
Before the weather or someone else happens along.

Section 3 to get your flight log txt.

Mavic Flight Log Retrieval and Analysis Guide

With the introduction of the Mavic Mini there has been a noticeable uptick in the number of posts requesting help with lost or crashed aircraft. While there is plenty of help and advice available on this forum, and detailed guidance and options on several other websites, I thought that perhaps a...

mavicpilots.com

So i got it, here it is the last log

 

[dedomocho8]

Post it here, and someone will take a look to see if there are any further clues to where it ended up. There are instructions on retrieving it in the links above. Or you can visit AirData or PhantomHelp for instructions.

Got it, here is a link with the last log

 

[sar104]

Got it, here is a link with the last log

Okay - there is nothing definitive in the log. It simply ends at 360.6 seconds, with the aircraft stationary at an altitude of 105 m, holding against a 9 m/s wind out of the east. Battery is 25% and signal quality is good, with no data loss prior to that.

So either the app crashed or disconnected from the RC, the RC disconnected from the aircraft, or the aircraft failed in mid-air. The only suggestive observation is that the disconnect occurred immediately after a very rapid full pitch excursion caused by you going from full reverse to full forwards and then back to neutral:



That kind of maneuver has been known to dislodge a loose battery, which of course would lead to a power-off fall.

If that happened, then it's possible to estimate the fall trajectory with wind drag, giving the following displacements.



That's shown in the GE image below (the green trace), and suggests that it may have crashed on the roof of the school building:

 

[dedomocho8]

Okay - there is nothing definitive in the log. It simply ends at 360.6 seconds, with the aircraft stationary at an altitude of 105 m, holding against a 9 m/s wind out of the east. Battery is 25% and signal quality is good, with no data loss prior to that.

So either the app crashed or disconnected from the RC, the RC disconnected from the aircraft, or the aircraft failed in mid-air. The only suggestive observation is that the disconnect occurred immediately after a very rapid full pitch excursion caused by you going from full reverse to full forwards and then back to neutral:

View attachment 140676

That kind of maneuver has been known to dislodge a loose battery, which of course would lead to a power-off fall.

If that happened, then it's possible to estimate the fall trajectory with wind drag, giving the following displacements.

View attachment 140678

That's shown in the GE image below (the green trace), and suggests that it may have crashed on the roof of the school building:

View attachment 140677

Thank you for your time and help. Idk how to read the graphics but I undestood overall What you said. So the 3d graphic estimated landing would be in the hypotetical case that the battery sliped off and the aircrafts free fell, right? or is the estimated landing place if the aircraft landed due to something being wrong?

 

[sar104]

Thank you for your time and help. Idk how to read the graphics but I undestood overall What you said. So the 3d graphic estimated landing would be in the hypotetical case that the battery sliped off and the aircrafts free fell, right? or is the estimated landing place if the aircraft landed due to something being wrong?

That would be a free-fall crash, which looks to me like the most likely cause.

The sudden disconnect makes it unlikely that the aircraft landed in that area, since if it were an app or RC problem then it would have continued with its attempted RTH. However, with the prevailing wind it is likely that such an RTH attempt would not have succeeded, and it would have autolanded somewhere on the direct track back to the home point.

The smart battery autoland level was 9%, giving it only around 15% battery to get back against the wind, but there are not enough data in that log to make a reasonable estimate of how much progress it would have made.

 

[dedomocho8]

Great super clear. Now... I'm gonna read deeply about this matter but, do you know if the battery coming out during the flight may be considered a "maufacturer's fail' and so be covered byu the warranty? I know it probably doesn't work that way but I don't wanna loose any legal loophole i can take advantage of...

 

[MAvic_South_Oz]

Great super clear. Now... I'm gonna read deeply about this matter but, do you know if the battery coming out during the flight may be considered a "maufacturer's fail' and so be covered byu the warranty? I know it probably doesn't work that way but I don't wanna loose any legal loophole i can take advantage of...

Battery disconnect is possibly a manufacturing fault, but more often (and more likely) just not engaged well by the pilot.
If you can find the drone, or battery, maybe DJI can check it out, they are usually pretty honest about defects in their goods . . . or even showing them the flight log MIGHT get you somewhere, even if it's just a discount on a new aircraft and battery.

If you recover the drone, did you take out Care Refresh ?
That covers you for the small fee if you recover the drone 'body', you probably don't need the battery if that parted company with the drone as expected.

Good luck . . . and excellent analysis / advice above @sar104 (as usual).

 

[Capt KO]

If you didn't, next time mark your drone. All mine have my ph# as well as the required FAA #. Good luck

 

[teccer]

taking off with 51% battery is not a good idea IMO, always takeoff with a full battery if possible

 

[dedomocho8]

UPDATE:
Thank you all for your help! I contacted DJI and because there's no signs of a pilot's fail. And thay couldn't determine what caused the disconnection and loss, they will send me a new one under the warranty. Thanks a lot!