Lost my DJI Mavic pro on my first flight [ DRONE FOUND]

[sar104]

Normally, if the drone is operating correctly, it returns home on its own and lands. In other cases it just lands where it is. Which also bring up a good point about a possible landing spot being significantly closer than we thought. Without RC connection it may have just started descending while drifting with th wind. I will look more closely tomorrow.

It's only going to do that if failsafe is set to autoland. That's not the default setting.

 

[Cyberpower678]

Sounds like the same RTH scenario mentioned in above post ?
But you log experts can't see a RTH, right ?

Hope you get your Mavic back @Govorin, what's the weather like ? Hope no bad rain or snow.

Hmm? We can clearly see if RTH was active or not. It wasn’t. M

 

[Cyberpower678]

It's only going to do that if failsafe is set to autoland. That's not the default setting.

It is if RTH won’t work. Then it just lands without going home.

 

[Govorin]

Sounds like the same RTH scenario mentioned in above post ?
But you log experts can't see a RTH, right ?

Hope you get your Mavic back @Govorin, what's the weather like ? Hope no bad rain or snow.

Weather is not really nice, been raining yesterday night and morning, so all these fields where I looked for it before was full of **** and water all my family helped me to look for it on 1st of January 2018haha. Hopefully will find it on that other spot. BTW here is picture of me looking for the drone

 

[sar104]

@Govorin, I decided to revisit this again after thinking about it some more. My previous post pointed to a location that is most likely nowhere near the actual landing spot.

Here's some more information about your flight:

• At the end of the flight log, your Mavic was flying at an altitude of 393 feet and drifting away from the home point with the wind at 26.9 MPH
• From reviewing the data prior to that point in the flight log, I'm estimating your Mavic continued to fly at a speed of no more than 26.6 MPH (most likely slower as it descended)
• According to your flight log, it would have taken your Mavic 48 seconds to land from that altitude
• Since your Mavic was flying in ATTI mode at the time, it would have started to auto land at its current location after the remote controller disconnected (assuming you didn't have the Remote Controller Signal Lost setting set to "Hover")
  
• If we assume the remote controller disconnected at the end of your flight log, your Mavic would have only flown for about 51 more seconds before landing

That means your Mavic would have most likely landed close to the yellow pin in the image below (which is located here). Since the wind speed/direction can only be estimated based on data recorded prior to the last recorded data, I'd recommend you look everywhere in the yellow box.

View attachment 27868

View attachment 27867

I've seen it stated before that loss of connection during ATTI mode will cause the aircraft to land immediately (if failsafe is set to RTH), but I've never seen that in any of the documentation. Obviously it makes a big difference in cases like this. Do you have a reference for that?

 

[sar104]

It is if RTH won’t work. Then it just lands without going home.

I've seen that stated, but I never seen it documented. Do we know that to be the case? I'd test it but I'm reluctant to turn off the RC after switching to ATTI.

 

[MAvic_South_Oz]

Weather is not really nice, been raining yesterday night and morning, so all these fields where I looked for it before was full of **** and water all my family helped me to look for it on 1st of January 2018haha. Hopefully will find it on that other spot. BTW here is picture of me looking for the drone

Oh no, that is so bloody bad for you, but you have a great family.
I hope to read here soon that you have found your Mavic and it all seems ok.

 

[msinger]

I've seen it stated before that loss of connection during ATTI mode will cause the aircraft to land immediately (if failsafe is set to RTH), but I've never seen that in any of the documentation.

I've never seen this in any of the documentation either.

 

[msinger]

why it would continue flying 51 more seconds? Not just land straight away on point where it loose signal?

By continue to fly, I meant the Mavic would have still been in the air. Since it was flying in ATTI mode, it would have been drifting with the wind as it descended.

is going to land everywhere he wants or he's going to find a good spot?

The Mavic does not look for a good spot to land when auto landing in a location other than the original home point (and when using the Precision Landing feature).

From where did you get this information that it should start landing and exactly after 51 sec ?

The Mavic is constantly calculating how long it would take to auto land at its current location. That information is useful in a case where the Mavic decides to auto land because the battery is too low to continue flying. If you convert your TXT flight log with the TXT-to-CSV Log Converter application, you can find that data in the "SMART_BATTERY.landTime " column of the CSV file it generates.

 

[sar104]

I've never seen this in any of the documentation either.

OK, I'm glad that I hadn't missed anything that fundamental. In that case how is it known that it behaves like that? While there are obvious advantages to it doing that (e.g. minimize drift to large distances), it's kind of a risky test, so have you seen flight logs that demonstrate that behavior? A quick check back through the ones that I've analyzed didn't turn up any suitable candidates.

 

[Cyberpower678]

OK, I'm glad that I hadn't missed anything that fundamental. In that case how is it known that it behaves like that? While there are obvious advantages to it doing that (e.g. minimize drift to large distances), it's kind of a risky test, so have you seen flight logs that demonstrate that behavior? A quick check back through the ones that I've analyzed didn't turn up any suitable candidates.

DJI stated that if it can't RTH it will simply land instead. This is also demonstrated when a GPS/RC jammer was tested on a Phantom 4. Since GPS and RC was lost at the same time, the drone landed instead of returning home.

 

[Govorin]

@Govorin, I decided to revisit this again after thinking about it some more. My previous post pointed to a location that is most likely nowhere near the actual landing spot.

Here's some more information about your flight:

• At the end of the flight log, your Mavic was flying at an altitude of 393 feet and drifting away from the home point with the wind at 26.9 MPH
• From reviewing the data prior to that point in the flight log, I'm estimating your Mavic continued to fly at a speed of no more than 26.6 MPH (most likely slower as it descended)
• According to your flight log, it would have taken your Mavic 48 seconds to land from that altitude
• Since your Mavic was flying in ATTI mode at the time, it would have started to auto land at its current location after the remote controller disconnected (assuming you didn't have the Remote Controller Signal Lost setting set to "Hover")
  
• If we assume the remote controller disconnected at the end of your flight log, your Mavic would have only flown for about 51 more seconds before landing

That means your Mavic would have most likely landed close to the yellow pin in the image below (which is located here). Since the wind speed/direction can only be estimated based on data recorded prior to the last recorded data, I'd recommend you look everywhere in the yellow box.

View attachment 27868

View attachment 27867

I don't know how to say thanks to you, I would give you million likes if I can, I can't believe I found it this morning 30 meters away from your pin. Thank you very much!!! You can't believe how happy I am now. I'll make a video of my story finding a drone and how I find and where it was, I have some material. Thanks a lot. You're the best of the best, so smart!! I would like to meet you in real and shake your hand and buy you a drink now my drone is in 6kg of rice, just wait for video if you're interested

 

[sar104]

DJI stated that if it can't RTH it will simply land instead. This is also demonstrated when a GPS/RC jammer was tested on a Phantom 4. Since GPS and RC was lost at the same time, the drone landed instead of returning home.

OK thanks - I just want to make sure that this is definitely how it behaves because it obviously makes a huge difference to location estimates when uplink is lost and the aircraft is in FC-induced ATTI (too few satellites or IMU exceptions).

 

[sar104]

I don't know how to say thanks to you, I would give you million likes if I can, I can't believe I found it this morning 30 meters away from your pin. Thank you very much!!! You can't believe how happy I am now. I'll make a video of my story finding a drone and how I find and where it was, I have some material. Thanks a lot. You're the best of the best, so smart!! I would like to meet you in real and shake your hand and buy you a drink now my drone is in 6kg of rice, just wait for video if you're interested

That's great news - and that also confirms that it auto lands on failsafe in ATTI. So not only did you get your Mavic back but you conducted a valuable experiment.

@msinger - nice work, and thanks for pointing out that undocumented failsafe behavior.

 

[Anthony Viscomi]

I don't know how to say thanks to you, I would give you million likes if I can, I can't believe I found it this morning 30 meters away from your pin. Thank you very much!!! You can't believe how happy I am now. I'll make a video of my story finding a drone and how I find and where it was, I have some material. Thanks a lot. You're the best of the best, so smart!! I would like to meet you in real and shake your hand and buy you a drink now my drone is in 6kg of rice, just wait for video if you're interested

Great ending!

 

[coop64]

Wow!!! Such a happy ending. It shows perseverance wins!!! It was evident from both sides, people who constantly tried to help OP, and OP and his family for making trips in search of lost Mavic.

Such a great community! Thanks everyone for your feedback and staying positive. I learned great bit from this incident even though I was just watching it from the sidelines.

 

[Govorin]

Thank you everyone again, I really appreciate your help and your time, without you I would never find it. Such a good people, helping for nothing, such a good community! I love you all I'm now even more happy than when I bought it. I don't know why, at the moment my drone is in the rice and I even don't know if is gonna fly or not, but I'm so happy

 

[Rnl]

You guys are the best, msinger I've seen you do this alot finding mavic, your a great and very smart person, glad you have our backs.

 

[Cyberpower678]

OK thanks - I just want to make sure that this is definitely how it behaves because it obviously makes a huge difference to location estimates when uplink is lost and the aircraft is in FC-induced ATTI (too few satellites or IMU exceptions).

Yea I totally forgot about that bit when I approximated the landing location. Put a whole lot more work in estimating than I needed to.

 

[Cyberpower678]

Thank you everyone again, I really appreciate your help and your time, without you I would never find it. Such a good people, helping for nothing, such a good community! I love you all I'm now even more happy than when I bought it. I don't know why, at the moment my drone is in the rice and I even don't know if is gonna fly or not, but I'm so happy

It most likely will. The drone had no power, nothing could have shorted.