Mavic Mini CRASH: Software error or my fault?

[Octavio.L]

Hi droney community! New forum member here. Joined to share my recent, tragic experience with my MM and see what's your opinion about what happened.

I was flying my MM on a regular quarantine afternoon, little cloudy yet not windy. Initiated the flight, and pushed just the left stick up in order to make the drone go up straight. Then I started to notice it started to go forward, without me ever touching the right stick, so I tried pushing the right stick down to try and make the drone come back: didn´t work. Next thing i tried pushing the "home button" didn´t work either and connection with the aircraft was lost. The drone kept flying forward until crashing into a building and wrecking into pieces: gimbal, camera, main case and battery bay are all heavily damaged with the gimbal and camera almost detached from the case . I checked the flight log and it´s clear that i never gave the command to go forward and i had flown before in the exact same place with succesful flights and landings.

Do you have any suggestions about what might have happened? Do you think DJI will cover the cost of repair/a new one?

Thank you so much for reading and I'll be even more grateful if I get to read your opinions Have a great weekend!

 

[BadWolf1]

If you can share the logs from your phone we can give you a better answer.
Where you took off, was there any metal structure (reinforced concrete , railings etc) nearby. This sort of thing happens when the compass reading is wrong at take off, and then comes right shortly into the flight.

 

[DrizzyDrones]

Sounds like it didnt have enough sat and was in atti mode so it drifted post the dat
File the text and we will know for sure Instructions on doing so is in a sticky thread at the top of the forum. Welcome to the forum

 

[boblui]

Sounds like IMU fault or magnetic interference. The .TXT and .DAT log files in the phone will be needed. Follow this thread to get them : Mavic Flight Log Retrieval and Analysis Guide

My Mini crashed in about the same way :

 

[Meta4]

Do you have any suggestions about what might have happened?

I could make a guess, but it might be wrong because I haven't see the flight data which will probably show exactly what happened.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report on the flight data.
Come back and post a link to the report it gives you.

 

[adamcrow64]

LIkely that the calibration was adrift. Be careful where you calibrate your mavic mini (I also recommend calibrating everytime as a habit). Watch out for calibration areas that may distort the Earths magnetic field.
Also check you have plenty of satellites for your GPS. Sometimes when your mavic is on the ground, it may not see all the satellites it can. Raising it slightly higher (like the 1.2m upon lift off) and waiting a little longer for better satellite sync is recommended.

 

[BossBob]

Sorry Adam, DJI do not recommend calibrating every time, only when necessary as indicated by their app. And the first thing I do if Go4 asks for a calibration is to move the drone and check for magnetic anomaly’s in the surroundings and on me. I still regularly fly my Mavic Pro, it’s only been calibrated 2 or 3 times in the 3 years I’ve owned it.

 

[Meta4]

LIkely that the calibration was adrift. Be careful where you calibrate your mavic mini (I also recommend calibrating everytime as a habit).

Compass calibration doesn't drift.
Calibrating every time is completely unnecessary and doesn't make your flying any safer.
Understanding what compass calibration actually does and when it might be needed, does make your flying safer though.
To get a better understanding of what it's all about, read the first post in this thread:

A short explanation of compass function, calibration and errors.

BACKGROUND The aircraft compass is often misunderstood, both in terms of function and purpose, but it is important to understand what the compass measures, why, and what happens to that information. At the most basic level the purpose of the compass is to measure the earth’s magnetic field in...

mavicpilots.com

 

[adamcrow64]

Compass calibration doesn't drift.
Calibrating every time is completely unnecessary and doesn't make your flying any safer.
Understanding what compass calibration actually does and when it might be needed, does make your flying safer though.
To get a better understanding of what it's all about, read the first post in this thread:

A short explanation of compass function, calibration and errors.

BACKGROUND The aircraft compass is often misunderstood, both in terms of function and purpose, but it is important to understand what the compass measures, why, and what happens to that information. At the most basic level the purpose of the compass is to measure the earth’s magnetic field in...

mavicpilots.com

I agree that it does not need to be done everytime (I've a Masters in Electrical Engineering and designed a lot of electronic systems). However it is easier to form a habit and do it.

 

[BossBob]

I agree that it does not need to be done everytime (I've a Masters in Electrical Engineering and designed a lot of electronic systems). However it is easier to form a habit and do it.

If you agree that calibration doesn’t need to be done every time, why recommend it?
A better habit to form would be to first check the status of the sensors, (as part of the preflight checklist perhaps), then to investigate what is causing the drone to request calibration and to move the drone away from possible problems. Calibration is the last thing I do as there is always the chance of replacing a good calibration with a bad one.

 

[adamcrow64]

If you agree that calibration doesn’t need to be done every time, why recommend it?
A better habit to form would be to first check the status of the sensors, (as part of the preflight checklist perhaps), then to investigate what is causing the drone to request calibration and to move the drone away from possible problems. Calibration is the last thing I do as there is always the chance of replacing a good calibration with a bad one.

Because, in any such system, the weak link is the human.
Every soldier, every pilot, every professional who needs to not make mistakes learns to develop habits that work to reduce errors in the course of a sustained campaign.

We don't always need to wear a seatbeat, or a helmet. But given enough time we eventually get hit. or make a mistake. The trick is to create safety habits that are no brainers and cause us to be aware.

You could fly your drone 1000 times and likely be ok. I personally find it hard to forgo my own experience and make it part of my process. Just being a conservative!

Don't replace what may well be a good calibration with a bad one. We're not robots.

 

[Meta4]

Every soldier, every pilot, every professional who needs to not make mistakes learns to develop habits that work to reduce errors.
Just being a conservative!

The words are somewhat cryptic but it sounds like you don't really understand what compass calibration really does.
I can't understand how anyone who knew what compass calibration is about could still continue to do it as a habit.

Did you read the first post in the link I gave in #8?

 

[BadWolf1]

LIkely that the calibration was adrift. Be careful where you calibrate your mavic mini (I also recommend calibrating everytime as a habit). Watch out for calibration areas that may distort the Earths magnetic field.

Calibration isn't for differences in the earth's field, but for how parts of the drone affect the sensor. Provided the calibration is done in a constant field it will be OK. The issue is if the field where you power is not lined up with the earth's field. What happens goes like this.
* Inertial to compass "Which way are we facing"
* Compass: North.
* Inertial. North it is ... right off we go , that's 5M North , 10M North, North 15M
* Compass: We're going west.
* Inertial , No North.
* Compass: West !
* Inertial , No you said North, we haven't been turning !
* Compass: Well we're going west NOW.
* Flight controller: We're off course, turn to get back !