Mavic 2 Pro Flyaway

[Jhun80]

Bear in mind that it was at 45 m altitude and moving at 12 m/s on a track of -133° when the downlink stopped:

View attachment 46462

Estimating the resulting ballistic trajectory from that point indicates that it could have travelled another 20 - 40 m while falling which would likely have cleared the house that it was approaching, and it certainly would not have ended up on the street:

View attachment 46463

Have you checked with the owners to see if it landed on the roof or in their swimming pool?

...And look for someone who have drones and scout around the buildings roofs and follow your previous footage.

 

[BlueBay]

Bear in mind that it was at 45 m altitude and moving at 12 m/s on a track of -133° when the downlink stopped:

View attachment 46462

Estimating the resulting ballistic trajectory from that point indicates that it could have travelled another 20 - 40 m while falling which would likely have cleared the house that it was approaching, and it certainly would not have ended up on the street:

View attachment 46463

Have you checked with the owners to see if it landed on the roof or in their swimming pool?

You could always get someone with a drone to do a search & rescue for you. I would imagine it would be visible from a roof in that area.

 

[Paul2660]

Did you get any interference errors while flying. With a populated area as dense as shown in the photo it's possible I would think that there would be a lot of local wifi interference. Still makes no reason why it did not RTH if RTH was not set to hover. And it set the RTH point apparently.

Hopefully it's at or near the house the diagram pointed to.

Paul C

 

[Goof]

Magnetic interference is always red mark! That's mean compass may see wrong geographic direction. North is not were should be for the drone. When you hear "Home Point..." it also says "check it on the map" - it tells you to check map on your device if the drone is pointing correct direction - if drone front is pointed North - on the map you have to see is pointing North. It is very important! If not - drone see wrong direction and following GPS is trying to compensate wrong movement - and you have fly away. Only way to save any GPS drone in this case - switch to manual mode. But we don't have it in our Mavic.

Look up dead reckoning. The aircraft is smart enough to know if the compass is not to be trusted, so it will attempt to fill in the gaps by monitoring changes in heading via the gyro.

If it knows where it was once pointed, and it knows how it has turned since then, it can gauge it's true heading without the compass. Over time though, rounding errors will build up to the point that this is also unreliable if the compass won't come back online (this could take minutes or hours depending on the IMU design). Presumably it might go into ATTI at that point, though I don't know the specifics.

What's more, the drone can still use gyro / accelerometer to remain safely upright without knowing or caring about its heading. Again, in the absence of a compass heading it's theoretically possible to use only IMU and GPS to deduce heading and fly home (move in a direction, see how latitude / longitude changes and perform simple math to determine relative heading to home point). This part is purely theoretical though, I don't know if DJI even need to do this...

TL;DR compass is not as critical as some people make out, anecdotally evident by DJI not bothering to make it redundant. Total compass failure by itself will not cause a "flyaway", there needs to be other issues present at the same time.

 

[CRCs Reality]

Look up dead reckoning. The aircraft is smart enough to know if the compass is not to be trusted, so it will attempt to fill in the gaps by monitoring changes in heading via the gyro.

If it knows where it was once pointed, and it knows how it has turned since then, it can gauge it's true heading without the compass. Over time though, rounding errors will build up to the point that this is also unreliable if the compass won't come back online (this could take minutes or hours depending on the IMU design). Presumably it might go into ATTI at that point, though I don't know the specifics.

What's more, the drone can still use gyro / accelerometer to remain safely upright without knowing or caring about its heading. Again, in the absence of a compass heading it's theoretically possible to use only IMU and GPS to deduce heading and fly home (move in a direction, see how latitude / longitude changes and perform simple math to determine relative heading to home point). This part is purely theoretical though, I don't know if DJI even need to do this...

TL;DR compass is not as critical as some people make out, anecdotally evident by DJI not bothering to make it redundant. Total compass failure by itself will not cause a "flyaway", there needs to be other issues present at the same time.

I don't know how different the guidance system on the Mavic2 is compared to the P3P (likely a lot), but the P3P forums had plenty of folks with experiences that would disagree, myself being one.

 

[sar104]

Look up dead reckoning. The aircraft is smart enough to know if the compass is not to be trusted, so it will attempt to fill in the gaps by monitoring changes in heading via the gyro.

If it knows where it was once pointed, and it knows how it has turned since then, it can gauge it's true heading without the compass. Over time though, rounding errors will build up to the point that this is also unreliable if the compass won't come back online (this could take minutes or hours depending on the IMU design). Presumably it might go into ATTI at that point, though I don't know the specifics.

What's more, the drone can still use gyro / accelerometer to remain safely upright without knowing or caring about its heading. Again, in the absence of a compass heading it's theoretically possible to use only IMU and GPS to deduce heading and fly home (move in a direction, see how latitude / longitude changes and perform simple math to determine relative heading to home point). This part is purely theoretical though, I don't know if DJI even need to do this...

TL;DR compass is not as critical as some people make out, anecdotally evident by DJI not bothering to make it redundant. Total compass failure by itself will not cause a "flyaway", there needs to be other issues present at the same time.

This is not quite correct. The FC uses a sensor fusion scheme in which, after initialization of the yaw by magnetometer data, the primary yaw estimate is based on the rate gyros with low-gain modification by magnetometer data. In the absence of magnetometer data the FC will immediately switch to ATTI. If there is a discrepancy between the rate gyro estimate and the magnetometer data then the FC will attempt to resolve the situation by rotating the aircraft, but there may be uncontrolled flight (often described as a flyaway) during this phase as it also attempts to hold position or fly a heading. The flight characteristics depend largely on the magnitude of the yaw error; 90° leads to the toilet-bowl pattern while 180° leads to uncontrolled linear flight. If it is unable to resolve then it will eventually switch to ATTI, if it hasn't already crashed into something.

However, the FC never attempts to fly by dead reckoning alone - the rate gyro drift is simply too large to trust without sensor fusion.

 

[Mattanous]

So sorry to hear that! I had a very similar situation and my Mavic is now on its way to California to be inspected. I saw my Mavic freak out and begin to take off and thank goodness a tree grabbed it. My flight log ended with hovering at 10ft but not all the weird things it started doing. I hope DJI takes care of you, keep us posted

Also for the sake of exposure you may want to post this on the DJI Forums online where DJI reps moderate it. Just so its out in the open.

 

[Kingram]

View attachment 46464

I would pass out new Flyers but this time offer a Reward , some kid could of found it and said this is cool and put it on the shelf in his room but a $100 reward would probably be cooler to him. Also post in Facebook and Nextdoor neighborhood groups. There was one pilot who lost him Mavic Pro and someone called two weeks later and said he found it on his balcony or roof.

 

[maxfaxdude]

Get the Marco Polo Tracker. I NEVER fly without it. I've used it to recover 3 drones in the field. 1 crash and 2 landings due to a low battery. 1 was over 1 mile away.

 

[Kingram]

Marco Polo Tracker -
https://www.amazon.com/Marco-Polo-A...r+Drone+Again+-+Starter+System+for+1+Aircraft

 

[Dizzle]

So I had this problem as well, the problem is when the app crashes, and reconnects it makes wherever the drone is at, the new home point once it reconnects. Since you didnt give any input to the controller after the app crashed I guarantee the drone landed right about where you 1st lost connection from the app. 1 reason especially for new flyers to keep the drone within your line of sight. Scout that area, if someone hasnt alrdy found it, or rained you may still be in luck

 

[ChopperLinc]

So I had this problem as well, the problem is when the app crashes, and reconnects it makes wherever the drone is at, the new home point once it reconnects. Since you didnt give any input to the controller after the app crashed I guarantee the drone landed right about where you 1st lost connection from the app. 1 reason especially for new flyers to keep the drone within your line of sight. Scout that area, if someone hasnt alrdy found it, or rained you may still be in luck

Good advice. I had such naive confidence that it would just return when it lost connection...

We'll see how cooperative the neighbors are. If I can it back in any condition I can make a Care Refresh claim.

 

[Gbshen]

I passed out flyers in the neighborhood. Unfortunately, it would have been better if I'd crashed it given I bought the Care Refresh that doesn't cover "loss."

You can purchase State Farm policy for the drone for $60/year that they say covers any loss
$1000 coverage on my drone.

 

[Clockman]

You can purchase State Farm policy for the drone for $60/year that they say covers any loss
$1000 coverage on my drone.

Unfortunately your rates will go up because you had a claim. You will be paying for the new drone many times over. I know somebody who submitted a claim for his crashed Phantom.....he was sorry.

 

[str455n]

So I couldn't resist the Mavic 2 Pro. It's my first drone.

For the five days I had it, I was impressed by the incredible piece of technology it was and excited about the new photographic possibilities.

I was flying on 9/11. Took off from the front of my house. When I connected the controller, it said there was mag interference, but the message went away. The drone established a home point and I took off, climbed to 150 feet (100 feet above the highest obstacle for about a half mile radius) for about a minute and a half, directly above my position, and looked at the sunset and lights. Everything seemed fine. At about 1:45, I turned and flew forward about 300 feet, and the drone just disappeared. No intermittent signal. It just totally dropped.

I immediately paused control inputs and waited about a minute, but it may not have been that long. Thinking the RC may still be connected i attempted to ascend to see if I could regain connection, and tried to get input on the map view, but it was not responding. Initiated RTH command, but don't believe it was ever received by the drone. The controller was continuously beeping and displaying "connecting..." Thinking the failsafe would kick in and it would come home, I waited about 5 min. Nothing. Walked directly under the last known point, still attempting to connect. Nothing. Took controller and drove in direction of flight path. Nothing.

Someone waited at the launch point in case it returned, but it did not.

Not being that experienced, it feels like a total in flight power failure, but I was hoping for some feedback.

DJI is reviewing records now. I attached the flight log.

Any advice appreciated.

Lincoln

DJI customer service are crap and won't bother if be shocked if they give you a new one. I have no confidence in them since they screwed me of mavic pro not my fault.

 

[hherbson]

No tile, no contact details....stupid.

Hey sunshine, why kick a guy when he's down? Your post offered nothing of value, other than to make you feel better.

 

[Inspirephil]

I passed out flyers in the neighborhood. Unfortunately, it would have been better if I'd crashed it given I bought the Care Refresh that doesn't cover "loss."

I purchased drone insurance from State Farm for my DJI Inspire 2 and it only cost me $85(annually) and it covers any type of loss, theft, etc. I also have DJI Care Refresh + just in case I need DJI for repairs but the State Farm insurance policy is a “no brainer” for loss of any kind.

 

[Inspirephil]

Hey sunshine, why kick a guy when he's down? Your post offered nothing of value, other than to make you feel better.

Absolutely!! This guy has enough problems without giving him a hard time.

 

[Inspirephil]

What surface did you take off from? When I had my Phantom3 Pro, I "almost" had a flyaway after launching from the roof of a parking garage (yeah, I know).. I had the same "Mag Interference" initially, but then it went away.
Once it was airborne, the compass and GPS disagreed on where north was, and it took off for parts unknown. Luckily I caught what was going on and switched to manual mode to bring it back, but it was a scary few moments.

If you launched from something with metal in it, I could see where it might cause confusion with the guidance system, and once it's in that state even if it tries to RTH, with the compass off it won't find home.

Yeah magnetic field interference causes a lot of flyaways.

 

[ChopperLinc]

Hey sunshine, why kick a guy when he's down? Your post offered nothing of value, other than to make you feel better.

Hahaha. You are a good person for defending me against me! I’m the OP. A little self-deprecation to admit how dumb it was of me not to put it on there. Oddly, didn’t even cross my mind.