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

[RayOZ]

Sorry for your loss. That would be a scary scenario for anyone flying their Mavic for the first time.
Seems like a lot of missing variables. I mean, if it had flown into open space, and if whatever that cause the interference is gone, won't the Mavic return to GPS mode and try to fly Home, if RC connection is lost? Unless losing the IMU calibration makes it go haywire.

 

[Govorin]

There's a video it shows that it falls when aircraft is disconnected. I'm more and more now interested in this, because when I saw my drone flying away already really far away, probably exactly on the last location where it lasts signal, I couldn't see it lighting anymore. But it might be because of little cloud that's why I couldn't see it lights anymore.. I'm not sure really now, OMG I don't understand why dji just can't fix this problem somehow. And why drone which cost me 1400eur with dji care don't have any GPS built in... So sad

 

[rfc]

because when I saw my drone flying away already really far away, probably exactly on the last location where it lasts signal, I couldn't see it lighting anymore.

Just out of curiosity: Did the thought ever occur to you to counteract the Mavic's climb and drift immediately when you saw it going crazy? You mention that this started when it was only 3 meters or so off the ground.

And for the pros:
Is it true that regardless of IMU, Compass, lack of GPS etc., that the A/C will always respond to stick input, unless it disconnects?

 

[Cyberpower678]

There's a video it shows that it falls when aircraft is disconnected. I'm more and more now interested in this, because when I saw my drone flying away already really far away, probably exactly on the last location where it lasts signal, I couldn't see it lighting anymore. But it might be because of little cloud that's why I couldn't see it lights anymore.. I'm not sure really now, OMG I don't understand why dji just can't fix this problem somehow. And why drone which cost me 1400eur with dji care don't have any GPS built in... So sad

It has GPS but it is pretty much useless if the compass and/or IMU goes awry. As for the video, that's an entirely different issue DJI covered and replaced. That onboard computer suffered a complete system crash mid-flight and the drone terminated the motors as a result.

The drone has a certain descent speed which is where the 51 seconds come from, but it will continue to fly in the direction it's flying when that happens. When the drone switches to ATTI mode, it disengages the GPS lock, so the drone needs to be flown manually.

 

[Govorin]

Just out of curiosity: Did the thought ever occur to you to counteract the Mavic's climb and drift immediately when you saw it going crazy? You mention that this started when it was only 3 meters or so off the ground.

He get around 3m high by me. Than automatically switch to atti mode, and than it get higher himself and start just flying away from me quiet fast.

 

[Cyberpower678]

Just out of curiosity: Did the thought ever occur to you to counteract the Mavic's climb and drift immediately when you saw it going crazy? You mention that this started when it was only 3 meters or so off the ground.

And for the pros:
Is it true that regardless of IMU, Compass, lack of GPS etc., that the A/C will always respond to stick input, unless it disconnects?

It will try to, but the responses may be erratic. If the IMU is functioning, then yes, you can still control the drone, albeit with more difficulty. If the IMU is failing, then you may be **** out of luck since the drone doesn't know what's going on anymore in terms of movement, and it might get more confused with stick inputs. There is a thing we call the Toilet Bowl effect. When the compass, GPS and IMU wig out in a certain manner, the IMU will think it's moving back and forth in a sinusoidal manner, it will try to counteract that motion and ends up flying in a sinusoidal manner. This in turn has the Mavic flying in a circle with increasing radius. Essentially it spirals outwards until it hits something. Some users have reported not being able to even get the drone to land when this happens.

 

[Govorin]

The drone has a certain descent speed which is where the 51 seconds come from, but it will continue to fly in the direction it's flying when that happens. When the drone switches to ATTI mode, it disengages the GPS lock, so the drone needs to be flown manually.

As I understand 51 second means from time when is lost control with rc drone continue drifting on wind with 26.6 mph and than it just landed after its gets lower automatically? Sorry, can you please answer me one question, what usually happens to drone if it's in atti mode, lost signal, it's says on remote that aircraft is disconnected what is he's next steps? Start landing ? From where is this information? I don't understand.

 

[sar104]

He get around 3m high by me. Than automatically switch to atti mode, and than it get higher himself and start just flying away from me quiet fast.

No - that's not correct. In terms of altitude the aircraft responded precisely to your stick inputs throughout the flight. The graph below shows the aircraft altitude (red trace) and throttle input (green trace). It's hard to see the response correlation between those because your throttle input was too intermittent. However, integrating the normalized throttle input with respect to time (the blue trace) shows the relationship between throttle and altitude, and you can see that it followed your input.

 

[sar104]

As I understand 51 second means from time when is lost control with rc drone continue drifting on wind with 26.6 mph and than it just landed after its gets lower automatically? Sorry, can you please answer me one question, what usually happens to drone if it's in atti mode, lost signal, it's says on remote that aircraft is disconnected what is he's next steps? Start landing ? From where is this information? I don't understand.

It maintains attitude and altitude (the definition of ATTI mode), simply drifting with the wind, until it reaches critical low battery, and then it auto lands. That was the basis of the earlier calculations to determine where it would most likely have landed.

 

[Govorin]

No - that's not correct. In terms of altitude the aircraft responded precisely to your stick inputs throughout the flight. The graph below shows the aircraft altitude (red trace) and throttle input (green trace). It's hard to see the response correlation between those because your throttle input was too intermittent. However, integrating the normalized throttle input with respect to time (the blue trace) shows the relationship between throttle and altitude, and you can see that it followed your input.

View attachment 27869

Sorry, I'm wrong than, I get it up myself(not very high) and than it starts flying away himself and I couldn't do anything. I was trying to use pause button, I just remembered now that he was offering me to return home even and I press "yes" but no luck, he keep flying away. Thanks for your time.

 

[MAvic_South_Oz]

The aircraft dropped into ATTI mode due to compass errors at 69 s, but it's not clear what caused them.

Remember short time ago, a fellow had a RTH happen, and his drone flew basically 180 degrees to his home location, and flew away ?
Maybe a similar thing happened and the OP took off from a vehcile roof or hood etc ?

The log might not have said anything about RTH, I don't understand the logs, haven't looked at one TBH, but just thinking out loud.

 

[sar104]

Sorry, I'm wrong than, I get it up myself(not very high) and than it starts flying away himself and I couldn't do anything. I was trying to use pause button, I just remembered now that he was offering me to return home even and I press "yes" but no luck, he keep flying away. Thanks for your time.

It switched to ATTI mode at 70 s, when it was roughly 6 m away and 17 m in altitude. Then it started drifting with the wind. Unfortunately you did not make a concerted attempt to control it (and I realized that ATTI mode is unfamiliar to most inexperienced pilots), with very few stick inputs, other than climbing throttle) for the rest of the flight:

 

[Govorin]

It switched to ATTI mode at 70 s, when it was roughly 6 m away and 17 m in altitude. Then it started drifting with the wind. Unfortunately you did not make a concerted attempt to control it (and I realized that ATTI mode is unfamiliar to most inexperienced pilots), with very few stick inputs, other than climbing throttle) for the rest of the flight:

View attachment 27870

But it started to fly away really quick, I couldn't even understand what to do, I just kind of lost. I tried pause button, I tried landing, he asked me if he can return home. So why he just doesn't return home? I understand completely that's is part of my error(probably), but still. What do you think of this situation? What dji will say to my case about this ? Do I have any chance of getting replacement?

 

[Cyberpower678]

As I understand 51 second means from time when is lost control with rc drone continue drifting on wind with 26.6 mph and than it just landed after its gets lower automatically? Sorry, can you please answer me one question, what usually happens to drone if it's in atti mode, lost signal, it's says on remote that aircraft is disconnected what is he's next steps? Start landing ? From where is this information? I don't understand.

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.

 

[Cyberpower678]

Which means I suggest you go an take a look at the suggested spot @msinger boxed on the map.

 

[sar104]

Remember short time ago, a fellow had a RTH happen, and his drone flew basically 180 degrees to his home location, and flew away ?
Maybe a similar thing happened and the OP took off from a vehcile roof or hood etc ?

The log might not have said anything about RTH, I don't understand the logs, haven't looked at one TBH, but just thinking out loud.

It's quite possible that magnetic interference at the takeoff point caused the problem, since the compass data are clearly bad right from takeoff.



The heading data are clearly bad - the aircraft started heading SW, and ended up drifting to the east, and yet the compass is locked in a NW heading. And the data are very noisy.

 

[Govorin]

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.

Thank you very much, I'll wait for your answer.

 

[Govorin]

Which means I suggest you go an take a look at the suggested spot @msinger boxed on the map.

I'll definitely go, I'm not sleeping again now, just can't sleep, I'm not going to give up, I want to find my drone )

 

[Cyberpower678]

Thank you very much, I'll wait for your answer.

Sorry. Take a look where msinger tells you to look. You might actually find it there.

 

[MAvic_South_Oz]

He get around 3m high by me. Than automatically switch to atti mode, and than it get higher himself and start just flying away from me quiet fast.

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.