Mavic pro crashed immediately after take off

[msinger]

I would really love to see this entire behavior myself and attempt to sort it out in time by switching to ATTI

Manually switching to ATTI mode won't help you resolve the issue. And in most cases, the aircraft auto switches to ATTI mode when it detects a compass issue like this.

Are there other fly-away scenarios that should be experienced apart from strong wind in upper air and drifting with or without P-mode?

Lots of things can cause someone to think their drone is flying away. See this guide:

Prevent a Crash or Flyaway with Your DJI Drone (The Complete Guide)

 

[sar104]

Manually switching to ATTI mode won't help you resolve the issue. And in most cases, the aircraft auto switches to ATTI mode when it detects a compass issue like this.

It's worth noting that there are two ways these situations (magnetic distortion at the takeoff point) can go bad:

The first is, as you mention, that the FC detects the yaw error, cannot resolve it, switches to ATTI, and the pilot, not being familiar with ATTI mode, loses control and crashes. That used to be the commonest result, especially with the earlier Phantoms when the FC would go to ATTI at the slightest hint of a problem.

More recently, with the later Phantom and Mavic firmware, the FC clearly tries harder to resolve the errors. For larger yaw errors (>~ 45°) that seldom works, and the uncontrolled flight is the direct result of not switching to ATTI, in which the FC continues to apply thrust in the wrong direction. That's what happened in this case and the best solution would be a prompt manual switch to ATTI, provided that the pilot was capable of flying in that mode.

 

[msinger]

That's what happened in this case and the best solution would be a prompt manual switch to ATTI, provided that the pilot was capable of flying in that mode.

Even if the OP had the Sport mode switch modified to ATTI and knew to switch it to ATTI, it seems he would have also had to know how to counteract the incorrect heading. Manually applying thrust in the intended direction should have made the aircraft fly in a different direction since the heading was off.

 

[sar104]

Even if the OP had the Sport mode switch modified to ATTI and knew to switch it to ATTI, it seems he would have also had to know how to counteract the incorrect heading. Manually applying thrust in the intended direction should have made the aircraft fly in a different direction since the heading was off.

That's not how it works. In ATTI mode all controls are relative to the aircraft frame of reference. Elevator just controls pitch, and aileron controls roll. The heading is then irrelevant since the FC is no longer paying any attention to direction of travel.

 

[msinger]

The heading is then irrelevant since the FC is no longer paying any attention to direction of travel

I guess it's only irrelevant as long as you're controlling the aircraft with your eyes? Wouldn't the aircraft direction in DJI GO still be off?

 

[sar104]

I guess it's only irrelevant as long as you're controlling the aircraft with your eyes? Wouldn't the aircraft direction in DJI GO still be off?

Right - the direction arrow would not be correct if there were a significant yaw error. I was envisaging switching to ATTI and taking control while close enough to see the aircraft. On the plus side, even beyond VLOS then at least the FC wouldn't be actively driving the aircraft in the wrong direction, and so while it may drift on the wind, at least it won't be accelerating out of control.

 

[Microwave89]

First thing I'd try is to fly in FPV as long as the video transmission works.
At the moment weather isn't promising but hopefully it doesn't rain and maybe I can these days do some experiments on the entire issue.

 

[lenal]

So is this the correct method before take off. "check the radar view of map and see where the N north icon is and then rotate the drone untill the red triangle points to the N north icon. The drone should now be facing north , which you may have a good idea is actually north or check north on your ipnone compass app before flight to establish north direction and make sure the drone is facing north. Finally change radar view back to map view and check red triangle is pointing towards a landmark that corresponds to the map"...

 

[Lon Denard]

I did "precision" take off and without any input drone started to drift away instead of climbing to 6m.
According to flight logs drone was facing north but I had placed it facing south. When you watch the embedded video then it seems that drone flew backwards but it was flying onward and when it became clear that it will crash the wall then I pulled right stick down to reverse the movement(as you can see from the video). IMU calibration was done 12h before the incident and compass 2h before. When I analysed flight txt log then I noticed that drone took off without problems but shortly had compass error that messed it up. I purchased the drone from DJI on 18.05.2018 and now I am wondering if this is something that could be covered by DJI warranty. As I understand then warranty for MC is 12 months?

The drone is messed up pretty hard. One of legs is broken, camera is broken, one of the forward looking sensor is broken and who knows what else.

So, should I submit a case to DJI?

Always submit a case...

 

[sar104]

So is this the correct method before take off. "check the radar view of map and see where the N north icon is and then rotate the drone untill the red triangle points to the N north icon. The drone should now be facing north , which you may have a good idea is actually north or check north on your ipnone compass app before flight to establish north direction and make sure the drone is facing north. Finally change radar view back to map view and check red triangle is pointing towards a landmark that corresponds to the map"...

You can start the drone facing any direction you want - you should just make sure that the aircraft arrow on the map is pointing in that direction.

 

[msinger]

So is this the correct method before take off. "check the radar view of map and see where the N north icon is and then rotate the drone untill the red triangle points to the N north icon. The drone should now be facing north , which you may have a good idea is actually north or check north on your ipnone compass app before flight to establish north direction and make sure the drone is facing north. Finally change radar view back to map view and check red triangle is pointing towards a landmark that corresponds to the map"...

Check these things:
Verify the compass is not being negatively affected by nearby interference

 

[Lon Denard]

You can start the drone facing any direction you want - you should just make sure that the aircraft arrow on the map is pointing in that direction.

Yea and not taking off from a metal structure helps as well. These drones are awesome pieces of technology but we don't need to test them. Taking off from a car, in close proximity to obstacles... All you need to add is high winds to almost guarantee a crash.

I'm not pointing this out to be a jerk, I'm hoping that other guys read this and understand clearly what pilot errors were involved so they can avoid them. Sometimes, we get deep into the technical aspects of a situation and it still feels at if guys want to blame the equipment somehow. "What procedure do I need to follow to keep the drone from messing up?" kinds of questions. Neither these drones nor DJI are perfect but I truly believe that if we spent just a minute or two doing a better job planning our flights, we could eliminate most of these incidents.

 

[Lon Denard]

These three videos were incredibly helpful to my understanding of the delicate balance between “magnetic north”, those “Global Positioning Satellites” orbiting the earth, the compass, IMU, and navigation technologies on board my Mavic Pro.

I see tons of questions about “compass errors”, and many testimonies of crashes and losses of drones that point to a lack of understanding of this particular aspect of our Mavics.

#1: DJI Mavic - Explaining Compass Errors & GPS Issues - Part 1 Flight Mode Basics

#2: DJI Mavic - Explaining Compass Errors & GPS Issues - Part 2 Compass Error

#3: DJI Mavic - Explaining Compass Errors & GPS Issues - Part 3 GPS


It was not before I gained at least a basic understanding of the effects of environmental factors that interfere with these onboard technologies before I began to grow in my skills and confidence in managing an aircraft that has gone awry. I am no “rocket scientist”, and I know that I’m a very long way away from understanding the scientific hows and whys. But, I did finally get “smart-enough” to stop assuming that every bad incident that happens with my Mavic is NOT a DJI defect, but due to my own lack of knowledge and experience.

These 3 videos I think would be of value to every noobie that enters this hobby.

Exactly. So many of these threads, YouTube and the internet in general is full of people that want to blame the equipment or DJI. They usually devolve into "I hate DJI!" rants because DJI looks at this data the same way that Sar does and comes to the same conclusions. Pilot error. They refuse to replace your broken toy and here comes the angry posts.

Now that's not to say that this guy shouldn't open a ticket. You have nothing to lose but a few minutes of your time. I'd point out that the drone should have warned you of the magnetic abnormality before takeoff. I would not mention how you took off unless pressed. Who knows? I got DJI to replace a drone I crashed into a bridge and didn't recover. If you get the right CSR...

 

[geckotrap]

With the take-off point so close to that building, it's very possible that the building construction and foundations include metal reinforcing ...
I've just done a 'street-view' on the site as shown in post #5 above ...
View attachment 70410
Note the bl**dy great iron gate next to your take-off point! Also that building is probably constructed from steel beams with cladding ...
Not an ideal launch site really!

Hey, look! Are those buildings corrugated metal???

 

[lenal]

It's worth noting that there are two ways these situations (magnetic distortion at the takeoff point) can go bad:

The first is, as you mention, that the FC detects the yaw error, cannot resolve it, switches to ATTI, and the pilot, not being familiar with ATTI mode, loses control and crashes. That used to be the commonest result, especially with the earlier Phantoms when the FC would go to ATTI at the slightest hint of a problem.

More recently, with the later Phantom and Mavic firmware, the FC clearly tries harder to resolve the errors. For larger yaw errors (>~ 45°) that seldom works, and the uncontrolled flight is the direct result of not switching to ATTI, in which the FC continues to apply thrust in the wrong direction. That's what happened in this case and the best solution would be a prompt manual switch to ATTI, provided that the pilot was capable of flying in that mode.

Can the mavic pro 1 be switched manually to atti mode ???if yes how?

 

[sar104]

Can the mavic pro 1 be switched manually to atti mode ???if yes how?

Yes - but it requires altering the fswitch parameter, as described in this thread on adding ATTI to the Mavic:

Mavic 2 Atti mode

 

[Bigbird48]

People say that when it goes to ATTI mode they somehow panic and crash. We had a saying back when I was young and had to pass a lifeguard swim test. It was sink and think . Ment when a drowning victim panics they try to grab you and can easily take you down with them so you sink they don't want to go under.Well with a drone when you panic I would think to go up that would give you time to think about whats going on and possably gain control of the AC and bring er home safe . Just a thought.