My first take off from hood - lost control and crashed

[HenriC]

It's my first time tried to take off from hood of my Toyota 4runner, after take off my remote controller can't work properly and few seconds later it crashed , as below video.

I'm curious what cause this accident, the sheet metal material or the generator under the hood effect the compass of drone?

Eventually, I thought my Mavic Pro won't work anymore, especially the first part bump the ground is the camera. After check the donre, the appearance no obvious damage and re-start the Mavic Pro the self-check is ok, I can keep my video shooting contiuiously.

I have to say, it's quite rugged.

 

[Haloweenhamster]

It's the metal, it normally says on the phone compass error calibrate or move away from any metal

 

[HenriC]

It's the metal, it normally says on the phone compass error calibrate or move away from any metal

Before take off, there're no any warning message shown, quite weird....

 

[TrayBoz]

From looking at the video, that looks exactly like what happens when there is a compass or IMU calibration error. Mine did that once when I took off in a parking lot from the ground (concrete) that had lots of metal rebar just under the surface, and I had to make an immediate forced landing (no damage Thank God).

Don't do a recalibration of any kind when near metal - especially on the hood or roof of a car. Don't launch from on top of a car. I always check that my compass and IMU are both in the GREEN before I launch, especially if I'm launching from a new location. Having said that, I've only had to recalibrate my compass and IMU once in 9 months.

Also, I always hand launch and hand catch, so I don't have to worry about being close to metal of any kind, or about dust or dirt getting into the air intake on the front, or into the motors.

Glad to hear there was no damage. Thanks for sharing the video.

 

[GerdS]

The Mavic cannot reliably detect a compass error while on the ground. Detection will only work reliably while airborne (e.g. if the compass indicates a very different direction than GPS track) and that might be already too late.
So, do a good compass calibraion in open field and NEVER take off or land on a metallic and maybe magnetic surface!

In case something like this will happen (TBE effect), there are rumors that the compass may get emmergency-calibrated by rotating the Mavic a few times around its yaw axis. That might have prevented the crash. Had no chance yet to validate.

 

[FlyGuy8675309]

You got lucky.

 

[m0j0]

What happened was you created a compass error by taking off from a lump of metal. lesson learned. Move the Mavic and take off from the ground.

 

[Mr. Salty]

Just to add: it's specifically because your vehicle and its engine are steel and iron. Last week I repeatedly took off and landed from an aluminum boat just fine.

Steel and iron are ferrous. Aluminum is not.

 

[Shaggy505]

It's my first time tried to take off from hood of my Toyota 4runner, after take off my remote controller can't work properly and few seconds later it crashed , as below video.

I'm curious what cause this accident, the sheet metal material or the generator under the hood effect the compass of drone?

Eventually, I thought my Mavic Pro won't work anymore, especially the first part bump the ground is the camera. After check the donre, the appearance no obvious damage and re-start the Mavic Pro the self-check is ok, I can keep my video shooting contiuiously.

I have to say, it's quite rugged.

That is a great perspective, loved watching that! Did you use native software or third party?

 

[Ping^Spike]

I read the thread title and thought you took off from your neighbourhood for the first time...

 

[BudWalker]

It's my first time tried to take off from hood of my Toyota 4runner, after take off my remote controller can't work properly and few seconds later it crashed , as below video.

I'm curious what cause this accident, the sheet metal material or the generator under the hood effect the compass of drone?

Eventually, I thought my Mavic Pro won't work anymore, especially the first part bump the ground is the camera. After check the donre, the appearance no obvious damage and re-start the Mavic Pro the self-check is ok, I can keep my video shooting contiuiously.

I have to say, it's quite rugged.

From your description and the video it seems this is launch-from-a-geomagnetically-distorted-site incident. If you want to know for sure you'll need to retrieve the .DAT so we can analyze it. But, if you replay the flight in to Go App I'm sure that you'll see that the heading indicator (red triangle on the map display) is not pointing in the right direction.

For these types of incidents this is the only way to know there is a problem and that a fly away is likely.

If you're interested in what the .DAT can show us take a look at

Compass error

And, this one seems to be popular
Looking for Trouble ??

 

[BudWalker]

...... there are rumors that the compass may get emergency-calibrated by rotating the Mavic a few times around its yaw axis. That might have prevented the crash. Had no chance yet to validate...

The Mavic does this, kinda. But, it's not a compass re-calibration. When there is a difference between Yaw (FC idea of heading) and magYaw (heading derived from magnetometers) the Mavic attempts to fix this by rotating the AC. The Yaw value is held constant until magYaw agrees with Yaw and then the rotation is stopped.

 

[HenriC]

From looking at the video, that looks exactly like what happens when there is a compass or IMU calibration error. Mine did that once when I took off in a parking lot from the ground (concrete) that had lots of metal rebar just under the surface, and I had to make an immediate forced landing (no damage Thank God).

Don't do a recalibration of any kind when near metal - especially on the hood or roof of a car. Don't launch from on top of a car. I always check that my compass and IMU are both in the GREEN before I launch, especially if I'm launching from a new location. Having said that, I've only had to recalibrate my compass and IMU once in 9 months.

Also, I always hand launch and hand catch, so I don't have to worry about being close to metal of any kind, or about dust or dirt getting into the air intake on the front, or into the motors.

Glad to hear there was no damage. Thanks for sharing the video.

Sounds hand launch and landing is a good idea, I only did this when I in the top of mountain due to no flat ground for landing.

Thanks for reply and sharing your experience.

 

[HenriC]

Just to add: it's specifically because your vehicle and its engine are steel and iron. Last week I repeatedly took off and landed from an aluminum boat just fine.

Steel and iron are ferrous. Aluminum is not.

I tried take off from the sunroof of my car once before take off from the hood of my car, as below video, it's works.

The material might be the key.

 

[HenriC]

That is a great perspective, loved watching that! Did you use native software or third party?

Thanks for reply and glad that you love my video.
I used to edit my film by Adobe Premiere.

 

[HenriC]

From your description and the video it seems this is launch-from-a-geomagnetically-distorted-site incident. If you want to know for sure you'll need to retrieve the .DAT so we can analyze it. But, if you replay the flight in to Go App I'm sure that you'll see that the heading indicator (red triangle on the map display) is not pointing in the right direction.
View attachment 20983
For these types of incidents this is the only way to know there is a problem and that a fly away is likely.

If you're interested in what the .DAT can show us take a look at

Compass error

And, this one seems to be popular
Looking for Trouble ??

Hi BudWalker, thanks for reply.

I'd screen shoot my flight record as below video.

I tried to force landing but failed.

Maybe I will contact with the DJI support and ask them figure out the root cause.

 

[mavicn00b]

I landed the mav on an iron tray on a truck and it threw all sorts of errors. Needless to say I didnt takeoff from there afterward and avoid metal objects at all costs.

 

[BudWalker]

Hi BudWalker, thanks for reply.

I'd screen shoot my flight record as below video.

I tried to force landing but failed.

Maybe I will contact with the DJI support and ask them figure out the root cause.

I looked some at the .DAT you provided. This .DAT came from the tablet and is missing a lot of data but I was able to confirm that the incident was caused by launching from a geomagnetically distorted site, i.e., the hood of your car. Here is where that happened.

If you want to know more you'll have to provide the .DAT from the Mavic itself. Provided that the Firmware is not 01.03.1000 you can retrieve the .DAT by looking here.

I'm not sure why you provided the .txt file. It was a different flight than the .DAT

 

[warlock 31]

It's my first time tried to take off from hood of my Toyota 4runner, after take off my remote controller can't work properly and few seconds later it crashed , as below video.

I'm curious what cause this accident, the sheet metal material or the generator under the hood effect the compass of drone?

Eventually, I thought my Mavic Pro won't work anymore, especially the first part bump the ground is the camera. After check the donre, the appearance no obvious damage and re-start the Mavic Pro the self-check is ok, I can keep my video shooting contiuiously.

I have to say, it's quite rugged.

One time I was in a grass field and could not take off from the ground. Tried the hood of my car. Lost control of the Drone and it landed in the tall grass by itself didn't hurt anything. so then I took it off from a cooler. Work just perfect then landed it on the hood because it is a much bigger platform. Same thing with my boat. Practicing in the driveway. Took off from engine cover and mavic was on its own lost all control. It was like lost the link. It hovered for a bit about 20 feet away and landed by itself. So I took off from the bow where the engines aren't and it lands and takes off just fine. I am glad I did not test this in the water that could have been really bad. Moral of the story is don't take off near anything metal.

 

[HenriC]

I looked some at the .DAT you provided. This .DAT came from the tablet and is missing a lot of data but I was able to confirm that the incident was caused by launching from a geomagnetically distorted site, i.e., the hood of your car. Here is where that happened.
View attachment 21153
If you want to know more you'll have to provide the .DAT from the Mavic itself. Provided that the Firmware is not 01.03.1000 you can retrieve the .DAT by looking here.

I'm not sure why you provided the .txt file. It was a different flight than the .DAT

Dear BudWalker,

Thank you for the analysis.

Avoid the geomagnetically distorted site is necessary , that what I learned from this incident, although I still can't catch the "Yaw" and "MegYaw" exactly mean and I'll try to figure it out later.

I'm sorry for provided the .txt file, I thought it is also part of the flight record log.