Nearly lost my Mavic Air this morning - Home Point changed randomly

Bondaneka · Mar 26, 2018

Had a terrible experience this morning with my 3 day-old Mavic Air. After several short flights and with a fresh battery installed, I flew the drone due west from me over some 90' trees to a distance of 359' and height of 212ft where I hovered for about 45 seconds with video recording. Having set the RTH altitude at 200' and noting that the Home Point had been properly recorded on take-off, I initiated a RTH expecting the drone to descend slightly and start its return. Instead of heading due East over the trees and back home it inexplicably headed North East at 18mph, maintaining a height of 212ft. I quickly lost sight of it and lost all contact. Examination of the flight record shows the Home Point correctly located at the launch point until the point at which I initiated RTH when it moved inexplicably to a random location 1000' North of its hovering position where it attempted to land on some bushes next to a main road. Panicking I jumped into the car headed off in the right general direction but having lost sight and contact feared the worst. I pulled over, got some intermittent contact and managed to climb the drone, sighting (through the camera) a field in the distance which I sent it towards before again loosing signal. I drove very quickly to the field and luckily managed to take back control with under 4 minutes battery remaining. As far as I know I did nothing wrong and certainly did not create the random RTH location which was way out of the park I was flying in and which I had never been to. I was lucky to recover the drone buy at am at a loss to understand why the Home Point changed to an entirely random location. Can anyone offer an explanation? (I had 13 satellites on take-off and no less than 16 for the remainder of the flight).

msinger · Mar 26, 2018

Bondaneka said:
Can anyone offer an explanation?

Please upload your TXT flight log here and post a link back here. You'll find instructions for locating your TXT flight log at that link.

genesimmons · Mar 26, 2018

wow thats quite a story, so glad u got her home, good job man

Bondaneka · Mar 26, 2018

I have downloaded the .txt files from my phone to a pc - can you please tell me how I determine which is the correct .txt file for the flight concerned?

msinger · Mar 26, 2018

Bondaneka said:
can you please tell me how I determine which is the correct .txt file for the flight concerned?

The log files are named like this:
DJIFlightRecord_[Date of flight]_[Time of flight in military time].txt

For example:
DJIFlightRecord_2018-03-18_[15-37-34].txt

Bondaneka · Mar 26, 2018

Thank you.

Bondaneka · Mar 26, 2018

Flight Record uploaded here:

DJI Flight Log Viewer - PhantomHelp.com

Thanks again.

Bondaneka · Mar 26, 2018

DJI Flight Log Viewer - PhantomHelp.com

Thio · Mar 26, 2018

Bondaneka said:
Had a terrible experience this morning with my 3 day-old Mavic Air. After several short flights and with a fresh battery installed, I flew the drone due west from me over some 90' trees to a distance of 359' and height of 212ft where I hovered for about 45 seconds with video recording. Having set the RTH altitude at 200' and noting that the Home Point had been properly recorded on take-off, I initiated a RTH expecting the drone to descend slightly and start its return. Instead of heading due East over the trees and back home it inexplicably headed North East at 18mph, maintaining a height of 212ft. I quickly lost sight of it and lost all contact. Examination of the flight record shows the Home Point correctly located at the launch point until the point at which I initiated RTH when it moved inexplicably to a random location 1000' North of its hovering position where it attempted to land on some bushes next to a main road. Panicking I jumped into the car headed off in the right general direction but having lost sight and contact feared the worst. I pulled over, got some intermittent contact and managed to climb the drone, sighting (through the camera) a field in the distance which I sent it towards before again loosing signal. I drove very quickly to the field and luckily managed to take back control with under 4 minutes battery remaining. As far as I know I did nothing wrong and certainly did not create the random RTH location which was way out of the park I was flying in and which I had never been to. I was lucky to recover the drone buy at am at a loss to understand why the Home Point changed to an entirely random location. Can anyone offer an explanation? (I had 13 satellites on take-off and no less than 16 for the remainder of the flight).

Bondaneka · Mar 26, 2018

Sorry - same link sent twice

msinger · Mar 26, 2018

Your flight log shows the home point was reset three seconds before you initiated RTH. Do you recall what you were doing in DJI GO at that time? Did you possibly manually reset the home point?

Thio · Mar 26, 2018

Hello all - came across the forum after some unfortunate circumstances with my Mavic Air yesterday. Very helpful and I look forward to hours of reading ahead.

So.....currently on Maui and have flown my Mavic Air 4-5 times with no issues. Was flying yesterday and after about 10-12 minutes of flying I was flying it back in. The MA was about 100 feet from me just stopped mid flight. No obstructions, plenty of battery etc in the flight path to have caused this. I lost all control of the it at this point and could do nothing. Tried swiping the auto land button but nothing. Then suddenly it started to fly straight up and away from me. I had a disconnected from drone error (or something to that affect). The real problem was the drone established a new home location at some point during my flight an dI have no idea how or why. So with no luck reconnecting to the drone I assume it "Returned Home" which had been reset over the ocean. Drone self landed in the ocean and it's gone.

Is this user error? What did I do to that would have caused a new home location to have been established? I know I did nothing wrong to cause it to randomly disconnect and am looking for any feedback. Do I have any chance of reimbursement from DJI? I assume I go to their website and start the claims process?

I have done all necessary firmware updates every time needed (and it seems like almost every time I fly in the last couple weeks). Also, calibrated the drone yesterday before my last flight.

For what it's worth, I also have a Phantom 4 and have had it for a couple years. Not brand new to flying.

Thank you for reading and any suggestions or info is much appreciated.

msinger · Mar 26, 2018

Thio said:
Hello all - came across the forum after some unfortunate circumstances with my Mavic Air yesterday. Very helpful and I look forward to hours of reading ahead.

Please start a new thread so it doesn't get mixed together with @Bondaneka's issue above.

Bondaneka · Mar 26, 2018

I assume you are talking about the event at 1m 54.8s? I had brought the drone into a hover and was scanning the horizon. I did nothing other than slew the drone to an approximately NE direction when I initiated the RTH. I did not enter any of the settings or map view. I still do not understand how an entirely random RTH point could have been generated> I'm sorry to trouble you with this - I am just trying to understand what might have happened so that I can avoid it reoccurring in the future. I really thought I had lost the drone forever!

timinator · Mar 26, 2018

Thio said:
Hello all - came across the forum after some unfortunate circumstances with my Mavic Air yesterday. Very helpful and I look forward to hours of reading ahead.

So.....currently on Maui and have flown my Mavic Air 4-5 times with no issues. Was flying yesterday and after about 10-12 minutes of flying I was flying it back in. The MA was about 100 feet from me just stopped mid flight. No obstructions, plenty of battery etc in the flight path to have caused this. I lost all control of the it at this point and could do nothing. Tried swiping the auto land button but nothing. Then suddenly it started to fly straight up and away from me. I had a disconnected from drone error (or something to that affect). The real problem was the drone established a new home location at some point during my flight an dI have no idea how or why. So with no luck reconnecting to the drone I assume it "Returned Home" which had been reset over the ocean. Drone self landed in the ocean and it's gone.

Is this user error? What did I do to that would have caused a new home location to have been established? I know I did nothing wrong to cause it to randomly disconnect and am looking for any feedback. Do I have any chance of reimbursement from DJI? I assume I go to their website and start the claims process?

I have done all necessary firmware updates every time needed (and it seems like almost every time I fly in the last couple weeks). Also, calibrated the drone yesterday before my last flight.

For what it's worth, I also have a Phantom 4 and have had it for a couple years. Not brand new to flying.

Thank you for reading and any suggestions or info is much appreciated.

Ouch. Sorry to hear about the loss of your aircraft. Must have been a sickening feeling. Can't offer any advice other than to open a case with DJI.

msinger · Mar 26, 2018

When you initiated RTH, did DJI GO ask you if you'd like your Mavic to return to the original home point or your current location? Or was there no such option?

MavicCF · Mar 26, 2018

Bondaneka said:
I assume you are talking about the event at 1m 54.8s? I had brought the drone into a hover and was scanning the horizon. I did nothing other than slew the drone to an approximately NE direction when I initiated the RTH. I did not enter any of the settings or map view. I still do not understand how an entirely random RTH point could have been generated> I'm sorry to trouble you with this - I am just trying to understand what might have happened so that I can avoid it reoccurring in the future. I really thought I had lost the drone forever!

Yes that's the one.
It really does seem strange as I believe it would be fairly hard to reset the home point without knowing it. There was a thread some time ago about a guy who reset his home point to his device's current location. Somehow his device misinterpreted it's location as being in a completely random spot, leading to a situation like the one you encountered.

Bondaneka · Mar 26, 2018

It did not give me an option and in any event I had not moved an inch from the launch point - so home point and current location would presumably have been the same.. I had certainly been nowhere near the randomly generated home point which was out of the park and 500 yards up the road in someone's front garden. I had a strong gps signal on my mobile phone (Huawei Mate 10 Pro running the most current version of Android).

msinger · Mar 26, 2018

The new home point was at the location where your mobile device was reporting it was currently located at that time. I'm not sure why the home point was reset since that prompt never appeared when you initiated RTH.