Lost Mavic Mini (flew out of control)

[daniel123]

Hello! I was flying my Mavic Mini on a calm day, all preflight checks seemed okay and the drone was preforming as normal. I flew the drone above my house up to about 150ft above to get a view of the sunset. Then almost immediately the drone jolted out of control, it seems as if one motor or propeller had gone out. It started flying and spinning rapidly up to 45 mph(over 15mph above the max listed speed.) the drone proceeded to spin in a circle until it fully lost connection to the controller at about 75ft above the ground. I did not realize it was this high up when I initially went to look for it so I’m not sure where it ended up. I have attached a video including the flight data just before it started spinning out of control until I lost connection. Any help as to where it might be on the map or what caused the issue would be greatly appreciated!! Thank you!

Link to video of flight path and information

 

[Rchawks]

Sorry to hear about your Drone. Someone will be along soon who could help you, I'm still a newbie myself. Good luck and Welcome to the forum.

 

[slup]

Hello! I was flying my Mavic Mini on a calm day, all preflight checks seemed okay and the drone was preforming as normal. I flew the drone above my house up to about 150ft above to get a view of the sunset. Then almost immediately the drone jolted out of control, it seems as if one motor or propeller had gone out. It started flying and spinning rapidly up to 45 mph(over 15mph above the max listed speed.) the drone proceeded to spin in a circle until it fully lost connection to the controller at about 75ft above the ground. I did not realize it was this high up when I initially went to look for it so I’m not sure where it ended up. I have attached a video including the flight data just before it started spinning out of control until I lost connection. Any help as to where it might be on the map or what caused the issue would be greatly appreciated!! Thank you!

Link to video of flight path and information

Hi there & welcome to the forum ? ...

Start up by sharing the flight logs that are stored in the mobile device you flew with ... read up here on how to retrieve ---> Mavic Flight Log Retrieval and Analysis Guide (read under section 3.) In this case we are interested in both the mobile device .TXT and the mobile device .DAT log ... retrieve them both & attach them then in a new post in this thread.

But just from the looks of that flight path & your description of what happened I would strongly lean towards that this isn't anything other than a power up of the drone in a highly magnetically disturbed environment deflecting the compass & by that initiate the IMUYaw to the wrong direction. Plain & simple ... this made the Mini lose it's knowledge about the correct heading direction.

Then high up when the Mini needed to apply thrust to hold position when the wind started to affect it ... the Mini applied thrust with the wrong motors (due not knowing where it was pointing) ... this creates a repeated loop of positional hold failures that creates that kind of path ... that toilet bowl like path also indicates that the IMUYaw error was around 90 degrees.

 

[Rchawks]

See, lol, they're good!

 

[old man mavic]

welcome to the forum ,sorry it wasn't under happier circumstances

 

[MA2 317]

Hello from the Hoosier Heartland daniel123.

Hopefully your problem can be diagnosed and resolved.

Welcome to the Forum.

 

[daniel123]

Hi there & welcome to the forum ? ...

Start up by sharing the flight logs that are stored in the mobile device you flew with ... read up here on how to retrieve ---> Mavic Flight Log Retrieval and Analysis Guide (read under section 3.) In this case we are interested in both the mobile device .TXT and the mobile device .DAT log ... retrieve them both & attach them then in a new post in this thread.

But just from the looks of that flight path & your description of what happened I would strongly lean towards that this isn't anything other than a power up of the drone in a highly magnetically disturbed environment deflecting the compass & by that initiate the IMUYaw to the wrong direction. Plain & simple ... this made the Mini lose it's knowledge about the correct heading direction.

Then high up when the Mini needed to apply thrust to hold position when the wind started to affect it ... the Mini applied thrust with the wrong motors (due not knowing where it was pointing) ... this creates a repeated loop of positional hold failures that creates that kind of path ... that toilet bowl like path also indicates that the IMUYaw error was around 90 degrees.

Thank you so much! It was such a weird occurrence. I have flown the mini several times at that height over my house before and nothing like that has ever happened before. What’s strange is no warning came up about the IMUYaw error. Anyway I’ll keep looking for it in around the predicted area where I have calculated for the crash. Thank you for this very useful information!

 

[hiflyer201]

Welcome to the forum!
As a resident EXPERT Slup says..post you logs.

 

[slup]

Thank you so much! It was such a weird occurrence. I have flown the mini several times at that height over my house before and nothing like that has ever happened before. What’s strange is no warning came up about the IMUYaw error. Anyway I’ll keep looking for it in around the predicted area where I have calculated for the crash. Thank you for this very useful information!

Understand that your first priority is to find your Mini ... & then to understand what caused this "Flyaway" ... both of these will benefit from you sharing the logs from the flight.

Thirdly it will be to great benefit to other members here ... this as they can learn from a possible mistake that you did during this flight.

Generally, this with a magnetic disturbed compass just in the moment when you power on your drone is little written about in the DJI documentation. Sometimes it will trigger a message saying you need to calibrate the compass, but sometimes not. It's though a fail safe pre-flight action you can do to be fully certain that this type of flyaway not will occur ... if you check the drone icon direction in the map view in your app after powering on & make sure that the icon is pointing equal to objects there (roads, houses etc.) as the drone does in reality ... if both the icon in the map & the drone in reality aligns everything is good to go, you can then be sure that the IMUYaw have been initialized correctly.

Thing's known for setting off the compass is reinforced concrete ... or nails/screws in a wooden deck, mainly all thing's of magnetic metal near your drone during power up can be fatal once on height & the drone needs to apply thrust to hold position.

A trick I always use is to power on my drone in my hand (without a big watch or bracelet), fully stretched out in front of me ... in that way I put the drone as far away from magnetic thing's as I can. After the liveview have appeared in the app I can safely put it on ground for take-off.

 

[Laborous]

Welcome to the forum from the beautiful woods of Maine!
You have come to the right place, our members should be able to decipher your data and help you locate your drone. Great advice Slup!

 

[Thomas B]

Welcome to the forum from the deserts of Arizona!
best is to post the logs, as stated above, to the link posted. Then the truth can be ascertained.

 

[daniel123]

Understand that your first priority is to find your Mini ... & then to understand what caused this "Flyaway" ... both of these will benefit from you sharing the logs from the flight.

Thirdly it will be to great benefit to other members here ... this as they can learn from a possible mistake that you did during this flight.

Generally, this with a magnetic disturbed compass just in the moment when you power on your drone is little written about in the DJI documentation. Sometimes it will trigger a message saying you need to calibrate the compass, but sometimes not. It's though a fail safe pre-flight action you can do to be fully certain that this type of flyaway not will occur ... if you check the drone icon direction in the map view in your app after powering on & make sure that the icon is pointing equal to objects there (roads, houses etc.) as the drone does in reality ... if both the icon in the map & the drone in reality aligns everything is good to go, you can then be sure that the IMUYaw have been initialized correctly.

Thing's known for setting off the compass is reinforced concrete ... or nails/screws in a wooden deck, mainly all thing's of magnetic metal near your drone during power up can be fatal once on height & the drone needs to apply thrust to hold position.

A trick I always use is to power on my drone in my hand (without a big watch or bracelet), fully stretched out in front of me ... in that way I put the drone as far away from magnetic thing's as I can. After the liveview have appeared in the app I can safely put it on ground for take-off.

Thank you for all the in depth replies it is really helpful! Unfortunately after searching for the drone for multiple hours I was unable to find it. I have sent out a message on Nextdoor as well hoping anyone could find it. The compass calibration did seem normal upon flying but I did notice something in the flight log(I will try to post the logs when I get a chance to) During the start of the flight and as I was gaining altitude I was pointing the camera north, but in the flight log it says the drone is pointing more south to southwest. This lines up with what you mentioned with the drone thinking it’s pointed one direction when in fact it wasn’t. In the meantime thought I am in contact with DJI support and seeing if I can get a replacement(just the drone.) Moving forward I will make sure to calibrate the compass every time, as the compass seems to be part of the problem, and probably won’t fly over my house anymore, I’m no expert but that’s just a general analysis from what happened and how I can improve next time. I will keep looking for it over the next few days but I really appreciate all the replies and feedback!

 

[Thomas B]

On the next drone maybe a strobe with alert sound (98dB) like the Firehouse ARC XLs or one of the trackers.

 

[daniel123]

Welcome to the forum!
As a resident EXPERT Slup says..post you logs.

On the next drone maybe a strobe with alert sound (98dB) like the Firehouse ARC XLs or one of the trackers.

That’s a great idea, will get one!

 

[daniel123]

Welcome to the forum!
As a resident EXPERT Slup says..post you logs.

I will do that asap.

 

[daniel123]

Sorry for the delay with the logs(I’ve never really done this before.) I’ve attached the .TXT file here, I was unable to retrieve the .DAT file because the sub folder in the files app “MCDatFlightRecords” was empty. After uninstalling and reinstalling the app it still was shown as empty. If there is any other way I can do this or if any other information is needed please let me know!

 

[slup]

... I was pointing the camera north, but in the flight log it says the drone is pointing more south to southwest...

Yeah, that observation mainly confirms this to be a yaw error due to a powering on the drone in a magnetic disturbed spot which deflected the compass in the moment of IMUYaw initialization.

I will make sure to calibrate the compass every time, as the compass seems to be part of the problem...

Calibrating the compass wouldn't stop this from happening ... that haven't anything to do with the incident. When you calibrate the compass the only thing it does is to measure the magnetic field coming from the drone itself so it can deduct that to only measure the earth mag field. A compass calibration is mainly only necessary when attaching or taking off equipment from the drone that can be slightly magnetic ... like LED light & such. Calibrating every time will only increase the risk for a bad calibration & other problems coming from that ... like crabbing in flight.

Sorry for the delay with the logs(I’ve never really done this before.) I’ve attached the .TXT file here, I was unable to retrieve the .DAT file because the sub folder in the files app “MCDatFlightRecords” was empty...

Yes, that's the correct .TXT log for this flight ... it's coupled with the mobile device .DAT log ending with FLY057.DAT.

But if it's missing it's hard to get access to the sensor data needed to pinpoint this with 100% accuracy as the .TXT log doesn't include that. But on the other hand ... all signs are already there, & together with your statement of the drone direction in reality & what you observed in the log ... we know pretty accurate what happened.

Lessons learned ...

-Power on the drone far up from the ground ... in your hand, let it start up & place it on ground after the live view have appeared in the app.

-Then check the drone icon in the apps map view & confirm that it's pointing equal relative other objects there as the drone does in reality.

-Don't calibrate the compass out from a habit ... if the app tells you to, question that & move away to another take off spot ... POWER DOWN & start up again & see if the calibration prompt still are there. If it's reappeared, only then do it, but be sure to check the drone icon in the map after again.

Good luck with finding your Mini!

 

[hiflyer201]

I will do that asap.

It takes some figuring out and I'd have to do some reading up but one of he main reasons I like this forum is watching the experts at work. I'm always impressed.
I'm Hoping there's a good end to this story!

 

[daniel123]

Yeah, that observation mainly confirms this to be a yaw error due to a powering on the drone in a magnetic disturbed spot which deflected the compass in the moment of IMUYaw initialization.



Calibrating the compass wouldn't stop this from happening ... that haven't anything to do with the incident. When you calibrate the compass the only thing it does is to measure the magnetic field coming from the drone itself so it can deduct that to only measure the earth mag field. A compass calibration is mainly only necessary when attaching or taking off equipment from the drone that can be slightly magnetic ... like LED light & such. Calibrating every time will only increase the risk for a bad calibration & other problems coming from that ... like crabbing in flight.



Yes, that's the correct .TXT log for this flight ... it's coupled with the mobile device .DAT log ending with FLY057.DAT.

But if it's missing it's hard to get access to the sensor data needed to pinpoint this with 100% accuracy as the .TXT log doesn't include that. But on the other hand ... all signs are already there, & together with your statement of the drone direction in reality & what you observed in the log ... we know pretty accurate what happened.

Lessons learned ...

-Power on the drone far up from the ground ... in your hand, let it start up & place it on ground after the live view have appeared in the app.

-Then check the drone icon in the apps map view & confirm that it's pointing equal relative other objects there as the drone does in reality.

-Don't calibrate the compass out from a habit ... if the app tells you to, question that & move away to another take off spot ... POWER DOWN & start up again & see if the calibration prompt still are there. If it's reappeared, only then do it, but be sure to check the drone icon in the map after again.

Good luck with finding your Mini!

Thank you for the guidance! I will make sure to do this when flying any drones in the future.

 

[daniel123]

It takes some figuring out and I'd have to do some reading up but one of he main reasons I like this forum is watching the experts at work. I'm always impressed.
I'm Hoping there's a good end to this story!

Yes, everyone here, especially slup has been a really great help!