FOUND! Lost my Mavic Pro during storm

[Usman]

When I made my original post, it was only five minutes after the OP. I did not know how much time had passed since it was lost. I was just trying to offer an option to try. If it didn't work for the OP, perhaps someone else will remember my suggestion when they find themselves in a similar situation.

I made the post when I returned home after searching it for more then 1 and half hour.

 

[Keule]

Without seeing the logs, only the screen capture, the telemetry recording stopped at 6.49 min flight time remaining.
The drone was pushed backwards by the wind by roughly 40 km/h.
Without taking the SmartBattery actions into account the drone would been drifted 4.5 km to SE.
It would have landed earlier, because reaching lower altitude windspeed will be reduced.

We need to see the logs to do more precise estimation. The man for this is @sar104

 

[BD0G]

Absolutely Post your Log and then tag SAR104 by posting an @ symbol and his username within this thread once the log is posted.

He is a genius with using the data to extrapolate and predict where ones lost drone is.

 

[Usman]

Hi Guys,

Back again, spent 4 hours searching for the drone in the morning where is expected it could be but no luck, most probably we searched out the fields in the direction it was heading to for 3kms until we gave up.

Here are the logs: DJI Flight Log Viewer - PhantomHelp.com

@sar104 calling you for help please.

Thanks in advance.

 

[Keule]

Just to give you an overview of your wind conditions:

 

[Usman]

Just to give you an overview of your wind conditions:

View attachment 39531

So it seems when i pressed RTH which was set to 100m, it caused the drone to drift back with the wind, at that particular altitude the wind speed is pretty high.

 

[Keule]

So it seems when i pressed RTH which was set to 100m, it caused the drone to drift back with the wind, at that particular altitude the wind speed is pretty high.

Yes.

... and that wind speed was really pretty high ...

Instead of relying on RTH, you should have brought the mavic to lower altitudes and fly the drone manually home.

But, IMHO you should have not flown in this wind.

 

[Usman]

Yes.

... and that wind speed was really pretty high ...

Instead of relying on RTH, you should have brought the mavic to lower altitudes and fly the drone manually home.

But, IMHO you should have not flown in this wind.

You can notice i was flying at about 70m meters when the wind was not too high, the storm came within seconds, i attempted to bring the drone down manually but it drifted backwards out of my sight so i panicked and pressed RTH and at that particular moment i couldn't imagine it would gain more altitude and will drift back on even more speed. Even then i gave it multiple tries to bring it down manually but no luck, it kept on going backwards...

 

[Keule]

Anyhow - things happened, we cannot revert events.
Let's see what sar104 estimations reveal about the drone's whereabouts...

 

[InvisibleName]

No help for you, but I hopefully any other new pilots will learn from your BIG mistake - check your local weather forecast & don't fly in high winds!!

Out of interest, what altitude had you set for the RTH? I suspect selecting RTH was the final nail in your drone's coffin, as it probably climbed even higher & into stronger winds! Select Sports mode, dive low & land where you can or try & head home is the best advice if you are caught out by excessive winds.

 

[Lapeer20m]

I’m sorry for your loss.

It’s a painful lesson. Sport mode and the lowest practical altitude would have improved your chances of saving the drone. Also, checking the weather forecast during pre-flight would have likely helped also.

Having a complete understanding of how rth works and knowing what the rth altitude was set at is pretty important when something goes wrong.

There is a mountain of information to learn about mavic and all of its functions and it takes a long time to put all of the knowledge into practice to become an expert pilot.

Again, I am sorry for your loss and hope you recover the bird.

 

[sar104]

Hi Guys,

Back again, spent 4 hours searching for the drone in the morning where is expected it could be but no luck, most probably we searched out the fields in the direction it was heading to for 3kms until we gave up.

Here are the logs: DJI Flight Log Viewer - PhantomHelp.com

@sar104 calling you for help please.

Thanks in advance.

I think it probably went further than you searched - around 4 km. If you extrapolate the battery level at the final rate of depletion to the autoland level at that altitude, and then estimate aircraft position based on drift speed in RTH to that time, plus around 30 s to descend from 80 m, you get the following:



That suggests it should have landed at around 9985 m from the home point. Extending the final track on the map to that distance gives:





With a guess of ± 3° uncertainty in the heading for that period of drift, we get a lateral uncertainty at 4 km of around 400 m, and that's probably not a bad uncertainty estimate on distance either. The resulting area estimate is depicted by the yellow circle. That's where I would look.

 

[Usman]

No help for you, but I hopefully any other new pilots will learn from your BIG mistake - check your local weather forecast & don't fly in high winds!!

Out of interest, what altitude had you set for the RTH? I suspect selecting RTH was the final nail in your drone's coffin, as it probably climbed even higher & into stronger winds! Select Sports mode, dive low & land where you can or try & head home is the best advice if you are caught out by excessive winds.

I admit it was my mistake to fly in that weather but indeed i could not imagine it would turn in to a disaster all of sudden and the storm would be that heavy.

RTH was set to 100m. You're right, when i turned it to the RTH mode, it gained more altitude.

 

[Usman]

View attachment 39538

With a guess of ± 3° uncertainty in the heading for that period of drift, we get a lateral uncertainty at 4 km of around 400 m, and that's probably not a bad uncertainty estimate on distance either. The resulting area estimate is depicted by the yellow circle. That's where I would look.

Thank you very much for detailed information. I have a question, you marked an auto land point and an estimated landing point, doesn't the drone vertically land if the battery is critically low?

By the way, we were quite close to the location you marked, so it will be much helpful now, will be heading there tomorrow morning and i hope we will be able to find it out, thanks a lot for the help again!

 

[Keule]

i hope we will be able to find it

Good luck for tomorrow!
If you find the drone, please mark the place with your phone or something to save the coordinates and give us a feedback. It'll be helpful for further rescue missions.

 

[soflms]

The hardest part is knowing it's out there somewhere. I'd keep looking. However you mentioned a giant storm, and water isn't exactly friendly to drones.

 

[BD0G]

Yes.

... and that wind speed was really pretty high ...

Instead of relying on RTH, you should have brought the mavic to lower altitudes and fly the drone manually home.

But, IMHO you should have not flown in this wind.

Actually , you should have switched the Mavic into Sport Mode using the Button on the top right side of the Remote Controller. Then pulled left stick down to get to lower elevations quickly. When the switch to Sport Mode is made the Mavic will have more RPM available to the props and will also be able to pitch forward at a greater angle. Allowing more slice through the high wind conditions.

In the standard P-GPS mode the Mavic cannot overcome wind velocities as high as are indicated and will drift backwards even at full thrust. Sport Mode gives one a fighting chance -combined with drop in altitude.
Another side benefit is - Switching to Sport Mode would have cancelled any other Intelligent Flight Modes IF you had the Mavic flying in one and given direct stick input maneuverability.

 

[BD0G]

Thank you very much for detailed information. I have a question, you marked an auto land point and an estimated landing point, doesn't the drone vertically land if the battery is critically low?

By the way, we were quite close to the location you marked, so it will be much helpful now, will be heading there tomorrow morning and i hope we will be able to find it out, thanks a lot for the help again!

Yes critical battery voltage will cause the Mavic to Autoland. While doing so it is not a straight line downwards as the wind is still pushing the Mavic in the direction of the wind. So its not like a rock falling from the sky straight down. I believe that Sar104 has included that in the estimate with the + /- 3 degree's.

Search the area indicated. Then find your Mavic. Sing the Praises of Sar104 and consider this a teaching moment. I personally think Sar104 should monetize his assistance and start a Paypal Donation account . He has helped out many forum members out of the goodness of his heart resulting in many found Mavics. Truly selfless acts of kindness.

 

[sar104]

Thank you very much for detailed information. I have a question, you marked an auto land point and an estimated landing point, doesn't the drone vertically land if the battery is critically low?

By the way, we were quite close to the location you marked, so it will be much helpful now, will be heading there tomorrow morning and i hope we will be able to find it out, thanks a lot for the help again!

As @BD0G already mentioned, the aircraft will start to descend at the autoland point but it would still be drifting with the wind as it descends - hence the additional 30 s or so of drift in the calculation that is represented by the distance from the marked autoland start point to the estimated landing point. The wind speed generally decreases with altitude and that appears to have been the case here based on the AirData estimates, so there is some uncertainty even if the estimated autoland start point is correct.

 

[sar104]

Yes critical battery voltage will cause the Mavic to Autoland. While doing so it is not a straight line downwards as the wind is still pushing the Mavic in the direction of the wind. So its not like a rock falling from the sky straight down. I believe that Sar104 has included that in the estimate with the + /- 3 degree's.

Search the area indicated. Then find your Mavic. Sing the Praises of Sar104 and consider this a teaching moment. I personally think Sar104 should monetize his assistance and start a Paypal Donation account . He has helped out many forum members out of the goodness of his heart resulting in many found Mavics. Truly selfless acts of kindness.

Thanks for the endorsement and the kind words. I'm doing this mostly because I enjoy a good puzzle, and if it helps find lost aircraft then that's a big bonus. I'm sure the same goes for @msinger and others who contribute similarly here and on PP.