DJI Drone Help Forum

Lost drone - Please help!

Hi,
I have just lost my mavic air and would be very appreciative if anyone has any tips about finding it!

As soon as it took off went wild and I had no control over it. I briefly regained control, almost caught it but then it went off again. There was nothing I could do - the controller had no impact.

It then said it lost signal (despite being close by) and I have not been able to find it!

The last point on the “Find my Drone” is at the point it disconnected (at 23m altitude) and therefore is no help.

I have retrieved the flight record and there appears to be an error “Not Enough Force/ESC Error” and “Exiting GPS mode: Unknown Error”. Please can someone advise to what these mean or the cause?

I have reviewed the flight record using airdata.com - https://app.airdata.com/flight/ae8fae7db6ad2fb96981b4fbe59d6282/GENERALNotifications.

I’m really devastated having only had it a couple of months and was enjoying it a lot! If anyone can help find it I would be so grateful. I have searched the area it last was connected but nothing.

Many thanks!

You need to either make your Airdata fully sharable, or upload your .txt file to the link below and share a link back here to that. We need the actual data itself.

Log Viewer

https://www.phantomhelp.com/LogViewer/PNWBLG4WKYP0K6ON5VDF/

Hopefully this works. Thanks for your help

It appears that you had control of the aircraft for the entire flight until the disconnect at the very end of the flight data. At approx 370 seconds, you applied full elevator flying the aircraft away from you until the end of the data. By that point the aircraft had switched back from ATTI to P-GPS. And should have initiated RTH after the last disconnect. But that is unknown. It will take a while to calculate a last possible position for your search area.

I suspect that the aircraft auto-landed in or about the area of the last known co-ordinance as shown in Image #2 below with the red circle. You might consider retrieving the tablet DAT which may provide additional information. For instructions see this link: Retrieve Tablet DAT


Thanks Fly_Dawg - this is a great help. I will try and retrieve the tablet DAT tomorrow.

Very much appreciate you looking into it!

Why are you thinking it landed there?

Since the GPS appeared to be working properly at the end of the flight log, I’m wondering if it flew back to the home point and landed in the river here:

That is the problem. Since there is no return track recorded, one can only assume an auto-land…near the last recorded position. Also, assuming that the OP did not turn off the RC, if indeed RTH occurred, signal would have been restored and the RTH flight would be in the data. Otherwise there was a serious aircraft failure of some sort, immediately prior or during RTH. Your theory is valid however.

The remote controller doesn’t always reconnect though. There have been cases where DJI drones returned home and landed right next to the remote controller without reconnecting.

Since the flight log abruptly ends, I guess we cannot rule out a landing/crash near the last known location. And maybe the aircraft switched back to ATTI mode after it disconnected like it did earlier in the flight.

Agreed. In this instance. Assumptions prevail, due to signal loss. With the issues that the aircraft presented during the flight, they may or may not have returned after the end of the data stream.

I highly recommend never flying a Drone without some type of tracking locator. I have the Marco Polo System, which comes with a small transmitter that emits a signal for several days. The system also comes with a Locator Device that in most cases will pinpoint the location of the missing Drone. It is important to review the flight logs and aerial pics/movies so you can get as close to the expected landing site. So sorry about your lost Drone, fortunately I have lost my DJI P3S, but was able to recover it both times. This advise on the Marco Polo Tracking System won’t be of much help after the fact, but again I highly recommend looking into the purchase of this devise if u plan to purchase another Drone. Keep looking, if your Drone did not end up in the river, maybe u or someone can locate it. I hope you had the Registration Number and your contact info affixed somewhere on your Drone. Best of luck. Hope this info is helpful to u.

Thanks everyone - your help is much appreciated.
We went round all of the area it could have crashed/landed but no luck. Have handed out lots of contact details so maybe someone will spot it. Fingers crossed anyway.

Thank you for the suggestion of the tracker too - will definitely look into this for next time - it sounds like a very good idea!

@msinger On the surface it “sounds like” the typical pattern when there is magnetic interference at the takeoff point like I would expect on a MPP - M2. Does the air react the same way?

I have not read the logs (don’t know how to) so I am asking, not suggesting.

That doesn’t seem to be the case here. The aircraft auto switched to ATTI mode due to a weak GPS signal (per the flight log). If @BellMavro decides to post the mobile device DAT flight log, we might find additional details there.

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Actually, I think in this one it is a case of launching from a geomagnetically distorted site. @BellMavro I’m betting you launched from a metal boat?

I’ve been developing an extension to CsvView that does some of the same IMU calcs on the .txt log files. Much like what @sar104 does using Igor. In the following the GPS location data is the red track and the location derived from integrating the IMU velocities is the green track. The paths diverge immediately after launch indicating the position computed from the IMU data doesn’t agree with the actual position from the GPS data. It can also be seen that the MA (shown by the yellow A symbol) is moving north east but the FC thinks the MA is pointing north west (shown by the green line anchored on the A symbol).

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