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Mavic 2 Lost to the Ages

Bryce steiner

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Joined
Mar 9, 2019
Messages
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Location
Antwerp, OH 45813
It’s a sad, sad day when you lose your drone. You leave the 99 to go after the one that’s lost and when you cannot find it you grieve.

In anticipation of spring I decided to fly tonight because it was so calm out. The sun was nice this evening and it was all good. The drone flew high and the drone flew low and flew graciously for miles. It could almost imagine the spring sun warming my face as I looked up into the sky!

Oh, but then tragedy struck. The dark clouds flew over and it began to rain on my drone parade (figuratively, of course) as I flew nearing a couple of rows of high tension power lines. The drone started going crazy!

Immediately, the drone started twisting (horizon distinctly tilted) to one side and came up in the DJI Go4 app that there was too much attitude. I’m sure it must have been writhing in pain, as it looked to me. It gave an error that there was too much wind. Funny, because it was completely calm even up higher as we have windmills that start turning at 6-7 mph. Then it gave an error the motor was beyond maximum speed. I told it to "Return to Home".

After that the screen said it was losing signal and everything went black (blank).

I’m sure it was crying out in pain as I wasn’t there to comfort it. I directly went to where the picture showed last on the screen. I got the coordinates and put them in my phone along with the DJI Go4 app and went right to it but it wasn't there. I scoured the cornfield where it said it had fallen, as much as possible I could, looked for the body lying cold and dead. I went back and forth, going up and down the rows in a large area but it was not to be found.

Visually I did not see it fall or fly as I had a some fields and trees in between. What I do know is it’s a sad day. :(
 
Do you have a way to read these? I don't know which is right. While searching the RC kept trying to turn off so that is probably why there are 4 files
 

Attachments

  • 2019-03-12 18_59_14-163DF9C00159V6.dat
    93 bytes · Views: 27
  • 2019-03-12 18_58_15-163DF9C00159V6.dat
    565 bytes · Views: 11
  • 2019-03-12 18_51_08-163DF9C00159V6.dat
    582 bytes · Views: 9
  • 2019-03-12 18_44_15-163DF9C00159V6.dat
    238 bytes · Views: 11
It’s a sad, sad day when you lose your drone. You leave the 99 to go after the one that’s lost and when you cannot find it you grieve.

In anticipation of spring I decided to fly tonight because it was so calm out. The sun was nice this evening and it was all good. The drone flew high and the drone flew low and flew graciously for miles. It could almost imagine the spring sun warming my face as I looked up into the sky!

Oh, but then tragedy struck. The dark clouds flew over and it began to rain on my drone parade (figuratively, of course) as I flew nearing a couple of rows of high tension power lines. The drone started going crazy!

Immediately, the drone started twisting (horizon distinctly tilted) to one side and came up in the DJI Go4 app that there was too much attitude. I’m sure it must have been writhing in pain, as it looked to me. It gave an error that there was too much wind. Funny, because it was completely calm even up higher as we have windmills that start turning at 6-7 mph. Then it gave an error the motor was beyond maximum speed. I told it to "Return to Home".

After that the screen said it was losing signal and everything went black (blank).

I’m sure it was crying out in pain as I wasn’t there to comfort it. I directly went to where the picture showed last on the screen. I got the coordinates and put them in my phone along with the DJI Go4 app and went right to it but it wasn't there. I scoured the cornfield where it said it had fallen, as much as possible I could, looked for the body lying cold and dead. I went back and forth, going up and down the rows in a large area but it was not to be found.

Visually I did not see it fall or fly as I had a some fields and trees in between. What I do know is it’s a sad day. :(

Great storytelling. Sorry for your loss.
 
I hope everyone can learn from my mistake - If you can afford the drone then you can afford an secondary way to track it. You cannot count on the last coordinates to the remote in the app. It could have flown way off especially if the battery was more than half.
 
Then it gave an error the motor was beyond maximum speed. I told it to "Return to Home".
Side note, Return to home is never to be used when things are malfunctioning. Got to fight manually.
RTH is the opposite of what many assume and depends on everything working perfectly. It's only good if YOU are lost or there is a loss of connection but everything else is fine.
 
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Side note, Return to home is never to be used when things are malfunctioning. Got to fight manually.
RTH is the opposite of what many assume and depends on everything working perfectly. It's only good if YOU are lost or there is a loss of connection but everything else is fine.

Looking back what I believe I should have done was take a picture straight down, kill the motors right then and just let it fall. Then it should have been right at the coordinates.
 
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Yes - that's the correct file. I have no idea what you were trying to do though. This aircraft was not making it home even without the problems it encountered - you flew it too far downwind. In terms of the event, at 812.5 s it lost connection for 35 s. Failsafe was set to "hover", and it was above the RTH height, and so it simply rotated to face the home point (south) and stopped. Unfortunately it looks as if that yaw maneuver generated disagreement between the IMU and the compass, and it ended up with an unrecorded yaw error. That led to uncontrolled flight to the southeast.

atti.png

speed.png

1552480070637.jpeg

The reported yaw at the end was southwest, which was clearly wrong since it was pitched forwards, rolled right and traveling southeast. The yaw was probably off by around 180°. The mobile device DAT file would likely show the correct magnetic yaw, but I'm not sure that it's even worth looking.

The log stops abruptly with the aircraft moving southeast at 20 m/s (45 mph). That may have been due to signal loss again, or FC failure. If the former then there is no way to estimate a reasonable end point. If the latter then it will be on the ground 50 - 100 m southeast of the last recorded point.
 
Yes - that's the correct file. I have no idea what you were trying to do though. This aircraft was not making it home even without the problems it encountered - you flew it too far downwind. In terms of the event, at 812.5 s it lost connection for 35 s. Failsafe was set to "hover", and it was above the RTH height, and so it simply rotated to face the home point (south) and stopped. Unfortunately it looks as if that yaw maneuver generated disagreement between the IMU and the compass, and it ended up with an unrecorded yaw error. That led to uncontrolled flight to the southeast.

View attachment 65840

View attachment 65841

View attachment 65842

The reported yaw at the end was southwest, which was clearly wrong since it was pitched forwards, rolled right and traveling southeast. The yaw was probably off by around 180°. The mobile device DAT file would likely show the correct magnetic yaw, but I'm not sure that it's even worth looking.

The log stops abruptly with the aircraft moving southeast at 20 m/s (45 mph). That may have been due to signal loss again, or FC failure. If the former then there is no way to estimate a reasonable end point. If the latter then it will be on the ground 50 - 100 m southeast of the last recorded point.
Yes - that's the correct file. I have no idea what you were trying to do though. This aircraft was not making it home even without the problems it encountered - you flew it too far downwind. In terms of the event, at 812.5 s it lost connection for 35 s. Failsafe was set to "hover", and it was above the RTH height, and so it simply rotated to face the home point (south) and stopped. Unfortunately it looks as if that yaw maneuver generated disagreement between the IMU and the compass, and it ended up with an unrecorded yaw error. That led to uncontrolled flight to the southeast.

View attachment 65840

View attachment 65841

View attachment 65842

The reported yaw at the end was southwest, which was clearly wrong since it was pitched forwards, rolled right and traveling southeast. The yaw was probably off by around 180°. The mobile device DAT file would likely show the correct magnetic yaw, but I'm not sure that it's even worth looking.

The log stops abruptly with the aircraft moving southeast at 20 m/s (45 mph). That may have been due to signal loss again, or FC failure. If the former then there is no way to estimate a reasonable end point. If the latter then it will be on the ground 50 - 100 m southeast of the last recorded point.
Dude I want to take a class from you, I always see you on here interperating the flight logs down so we can understand them. Knowledge is one thing but thats a gift. Im sure a lot of people would be interested in an intrudictory class. Just sayn
 
Visually I did not see it fall or fly as I had a some fields and trees in between.
That and the drone being 6 miles away which might have also been a factor?
Looking back what I believe I should have done was take a picture straight down, kill the motors right then and just let it fall. Then it should have been right at the coordinates.
Do cached images have exif info?
 
I have no idea what you were trying to do though. This aircraft was not making it home even without the problems it encountered - you flew it too far downwind.
Well given he said "there was no wind" he just did the classic "no wind here gives zero information about wind somewhere else".
 
Well given he said "there was no wind" he just did the classic "no wind here gives zero information about wind somewhere else".

The wind was not excessive - about 10 mph out of the south at the flight altitude. It was still enough that at full distance and less than 50% battery remaining it was not making it home.
 
Well given he said "there was no wind" he just did the classic "no wind here gives zero information about wind somewhere else".
You're right. I gave the info the best that I know of. We do live in an area with wind and have many windmills. Last night, unless there was a strange gust, was very calm in all the places I was.
The info that SAR104 came up with confirms the trajectory I'm going to check shortly.
 
Dude I want to take a class from you, I always see you on here interperating the flight logs down so we can understand them. Knowledge is one thing but thats a gift. Im sure a lot of people would be interested in an intrudictory class. Just sayn

Thanks. I am still writing a guide on the subject, but very slowly. Unfortunately, any detailed attempt to analyze the logs requires software and mathematical techniques that most users will not have.
 
The wind was not excessive - about 10 mph out of the south at the flight altitude. It was still enough that at full distance and less than 50% battery remaining it was not making it home.

It didn't need to make it home because it was going to land nearby. I have several friends right along the road there. That I was going to land at based upon the battery usage.

I sure appreciate what you came up with. I think what you are working on will be greatly beneficial. Are you planning on selling the software or for research only?
 
It didn't need to make it home because it was going to land nearby. I have several friends right along the road there. That I was going to land at based upon the battery usage.

I sure appreciate what you came up with. I think what you are working on will be greatly beneficial. Are you planning on selling the software or for research only?

It's not my software - I was referring to the kind of data analysis software that is necessary to manipulate and analyze the data. These programs (MATLAB, Mathematica, Igor Pro etc.) are not cheap and require a reasonable familiarity with mathematics to use them.
 
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