Today, I had a fly away with my Mavic Pro.
I made of video to show the event.
Youtube LINK (may take time to be 4k res)
It happened in seconds and the drone flew sideways into a building at the side and dropped from the air. Luckily there are no people around.
The building is a low building of 6 floors and to the other side is an open lawn. I was approximately 20m(66ft) from the building and waited over a minute to make sure I had a good lock. The remote announced my home point was recorded.
Usually the mavic is rock solid in it's position but it shot off with a 11 sat lock(4/5 bars) with no input in the right stick through the whole ordeal. It wasn't drifting to the side, it accelerated and reached a speed of 15.4km/h at the impact. It was about 3 seconds from the start of the drift to the impact. I still don't want to call it a drift because it shot off like the right stick was on full right(right stick was never touched since launch).
I'm not sure how this happen or if DJI would cover this. I'm pretty bummed out as you can imagine and of course lost the confidence. I'm about 7 months since I have bought it so I'm not sure what they will cover.
Any thoughts?

Hi there, we are so sorry for the crash accident, please contact our support team www.dji.com/support to start a ticket for the data analysis, our team will help figure out what happened and whether the warranty service can be provided, thank you.

DJI Mindy Posted at 6-28 01:50
Hi there, we are so sorry for the crash accident, please contact our support team www.dji.com/support to start a ticket for the data analysis, our team will help figure out what happened and whether the warranty service can be provided, thank you.

Thank you for your prompt response. I just sent an Email from the Support Page. There isn't Online support for the Singapore market so I assume that's the best way.

Use this link Log viewer upload.
to post your log here. It will tell the truth about what happened.

G_Sig Posted at 6-28 06:39
Use this link Log viewer upload.
to post your log here. It will tell the truth about what happened.

Ah, thank you for that.
I'm not familiar with this. If anyone is curious how to get the log TXT file, you use iTunes and File Share from the DJI Go app to drag and drop the folder out.
So I am seeing a "Compass Error" that started 4.3ft off the ground and continued. It's weird because I had no Compass Error notifications on the screen. Everything was fine and it took off. At 12.1ft I got a "GPS Position NoMatch". I have a 10 sat GPS lock at that position.
I once had a Compass Interference before and that limits the altitude to 15m I believe. Something very low. But I was able to get to about 25m so it doesn't seem to be the same thing.
If I knew there was a Compass problem, I would never lift off.

fans19db8551 Posted at 6-28 07:21
Ah, thank you for that.
I'm not familiar with this. If anyone is curious how to get the log TXT file, you use iTunes and File Share from the DJI Go app to drag and drop the folder out.
So I am seeing a "Compass Error" that started 4.3ft off the ground and continued. It's weird because I had no Compass Error notifications on the screen. Everything was fine and it took off. At 12.1ft I got a "GPS Position NoMatch". I have a 10 sat GPS lock at that position.

Best to copy the link to log viewer and post it here.
These type of compass error is sometimes because of some iron underground where you took off.
It can also be because of you are to close to a car when you take off.

G_Sig Posted at 6-28 07:33
Best to copy the link to log viewer and post it here.
These type of compass error is sometimes because of some iron underground where you took off.
It can also be because of you are to close to a car when you take off.

https://www.phantomhelp.com/LogViewer/35Q31NC7B9H5NKZLJD77/

fans19db8551 Posted at 6-28 07:41
https://www.phantomhelp.com/LogViewer/35Q31NC7B9H5NKZLJD77/

Flight log
This is most likely because of some metal close to take off spot.
You got warning about strong interference at startup.

G_Sig Posted at 6-28 10:24
Flight log
This is most likely because of some metal close to take off spot.
You got warning about strong interference at startup.

Yeah I saw the interference notification that pop up and went away immediately at the beginning. In an urban environment it's not unusual to see those. It wasn't a continuous warning and the Mavic locked in enough GPS sats and there is no RC to Mavic reception issue.
The metal on the ground theory i feel isn't a strong one because there is no warning of compass or magnetic interference from the ground. The first warning in the log is while it's in the air.
From my experience(lvl 16, 7mo) a fence could give a compass interference which would limit the height. Doesn't seem to be the situation as it had no altitude restriction and no pop up warning. Metal in the ground usually gives a Magnetic interference warning in which the drone will not even take off. From the Mavic's perspective and from me the user, the drone was ready to go.
I'm curious why these warnings lay buried in the flight log when i cannot even see it on my smartphone screen or even the flight record. There was no indication anything was wrong.

fans19db8551 Posted at 6-28 18:06
Yeah I saw the interference notification that pop up and went away immediately at the beginning. In an urban environment it's not unusual to see those. It wasn't a continuous warning and the Mavic locked in enough GPS sats and there is no RC to Mavic reception issue.
The metal on the ground theory i feel isn't a strong one because there is no warning of compass or magnetic interference from the ground. The first warning in the log is while it's in the air.
From my experience(lvl 16, 7mo) a fence could give a compass interference which would limit the height. Doesn't seem to be the situation as it had no altitude restriction and no pop up warning. Metal in the ground usually gives a Magnetic interference warning in which the drone will not even take off. From the Mavic's perspective and from me the user, the drone was ready to go.

I wanted to add, the strong interference was at 1.3 seconds from start up. It's possible that it's from me standing over the Mavic when I'm activating the button.

fans19db8551 Posted at 6-28 18:06
Yeah I saw the interference notification that pop up and went away immediately at the beginning. In an urban environment it's not unusual to see those. It wasn't a continuous warning and the Mavic locked in enough GPS sats and there is no RC to Mavic reception issue.
The metal on the ground theory i feel isn't a strong one because there is no warning of compass or magnetic interference from the ground. The first warning in the log is while it's in the air.
From my experience(lvl 16, 7mo) a fence could give a compass interference which would limit the height. Doesn't seem to be the situation as it had no altitude restriction and no pop up warning. Metal in the ground usually gives a Magnetic interference warning in which the drone will not even take off. From the Mavic's perspective and from me the user, the drone was ready to go.

What will happen when you turn on your Mavic on place with this kind of interference it that your compass will set up wrong parameter at startup.
When you take off and gain altitude this will fade out and then you get compass error.
When you have fixed your Mavic you should test this with the sensor page open in the Go 4 app.
You will see the numbers change  for the compass.
I have seen this many times for the last 3 years and you wont bee the last one to see this.

G_Sig Posted at 6-29 17:31
What will happen when you turn on your Mavic on place with this kind of interference it that your compass will set up wrong parameter at startup.
When you take off and gain altitude this will fade out and then you get compass error.
When you have fixed your Mavic you should test this with the sensor page open in the Go 4 app.

If there was an interference, why isn't there a Compass interference notification on the ground? It was sitting there for over a minute.
If there was a strong interference in the air, wouldn't it go straight into ATTI mode?

Do you mean go back to the same place and view the compass sensors via the Go app?
Or do you mean to set the mavic at any location and lift it off and notice how the compass number changing when from the ground position to the air position?

The compass (actually there are 2 in the Mavic) are the most critical sensors for orientation/direction. GPS lock is secondary in importance as its a constant variable throughout a flight as each satellite signal is captured and then handed off. GPS's primary function is to provide position - not orientation.... so if you lose compass accuracy through interference the drone will register where it is in relation to the constellation of satellites but not orientation  - which why all navigation systems still use some form of compass to navigate by. Some aircraft also use inertial systems too - much like spacecraft in order to fix orientation in 3d space - (old days with spinning gyroscopes, modern times with laser beam cavities). I think DJI could improve on how to inform via the console, compass errors and actually not allow a manual takeoff as an extra safety measure that could be user selectable much like RTH attitude settings. One thing I'm now always wary of is 'compass gimbal lock' which seems to be dependent on take off orientation relative to magnetic north. (This is where the craft's compass flips 180 degrees internally - DJI firmware has been written to take this into account but it can still cause a wobble or 'jink'/roll in flight. Looking in detail at the flight log, you can kind of see what happened - when you were still on the ground the GPS was seeing up to 11 satellites but as the craft wasn't moving the compass would have stayed in place - as soon as you took off the compass would have started to drift and then a mismatch would have been registered by the drone software and then negated the GPS input (you can see the moment when on the PhantomHelp.com flight log page - when the GPS bars suddenly turn to a single red bar. At that point your drone is in 'fly-away' state and is drifting in the wind/breeze. Within such a tight space you have little opportunity to try and save the flight by raising the craft to be clear of the trees and near-by building. Once in open sky it might have been possible to regain control as long as you have VLS and RC contact, by switching into sport mode and manually flying and landing as soon as you can in a nearby open space.

fans19db8551 Posted at 6-30 01:51
If there was an interference, why isn't there a Compass interference notification on the ground? It was sitting there for over a minute.
If there was a strong interference in the air, wouldn't it go straight into ATTI mode?

All these screenshots are taken inside and within 50 cm movement of the drone up on extendable dining table.
IMU is right all the time but compass is badly messed up.
All this reading will give you compass error but just the red (+500) will stop you from take off.
Reading 0 to 300 will bee green BUT you want this reading to bee as low possible ( 10 - 30) is great.
To test this you don't have to take off just lift the Mavic with your hand and sensor page open in Go 4 app.

Lamplighter55 Posted at 6-30 02:16
The compass (actually there are 2 in the Mavic) are the most critical sensors for orientation/direction. GPS lock is secondary in importance as its a constant variable throughout a flight as each satellite signal is captured and then handed off. GPS's primary function is to provide position - not orientation.... so if you loose compass accuracy through interference the drone will register where it is in relation to the constellation of satellites but not orientation  - which why all navigation systems still use some form of compass to navigate by. Some aircraft also use inertial systems too - much like spacecraft in order to fix orientation in 3d space - (old days with spinning gyroscopes, modern times with laser beam cavities). I think DJI could improve on how to inform via the console, compass errors and actually not allow a manual takeoff as an extra safety measure that could be user selectable much like RTH attitude settings. One thing I'm now always wary of is 'compass gimbal lock' which seems to be dependent on take off orientation relative to magnetic north. (This is where the craft's compass flips 180 degrees internally - DJI firmware has been written to take this into account but it can still cause a wobble or 'jink'/roll in flight. Looking in detail at the flight log, you can kind of see what happened - when you were still on the ground the GPS was seeing up to 11 satellites but as the craft wasn't moving the compass would have stayed in place - as soon as you took off the compass would have started to drift and then a mismatch would have been registered by the drone software and then negated the GPS input (you can see the moment when on the PhantomHelp.com flight log page - when the GPS bars suddenly turn to a single red bar. At that point your drone is in 'fly-away' state and is drifting in the wind/breeze. Within such a tight space you have little opportunity to try and save the flight by raising the craft to be clear of the trees and near-by building. Once in open sky it might have been possible to regain control as long as you have VLS and RC contact, by switching into sport mode and manually flying and landing as soon as you can in a nearby open space.

thanks for the info.
Actually on my screen, the gps never turns 1 bar and red. the flight record also is the same. that's what perplexes me the most is all the hidden warnings in the flight log text that the user cannot see.
I promise you there was no breeze to carry the drone. it wasn't hovering in atti. It decided to bank sideways in an accelerated rate. it traveled approx 30m to the impact area. that was within 3-4 seconds. when i have looked up, it had already hit. it's why you see no input in either joystick as i had no time to react. if it was 60m away, I would have had maybe a few more seconds? And this is assuming it's at the hit speed of 15+km/h. i'm guessing it would accelerated to max P-mode speed which i think is 30+km/h. So maybe an extra 2 seconds if I was at 60m? If it had cleared the roof, it would have been a rogue projectile flying across the city. Now, I could have possibly raised it to 300m altitude to clear all max city structures but then i'm in violation of the drone rules. It hit the building and it hit nobody when it fell from the air. So maybe it was the best case scenario for the malfunction.

fans19db8551 Posted at 6-30 09:10
thanks for the info.
Actually on my screen, the gps never turns 1 bar and red. the flight record also is the same. that's what perplexes me the most is all the hidden warnings in the flight log text that the user cannot see.
I promise you there was no breeze to carry the drone. it wasn't hovering in atti. It decided to bank sideways in an accelerated rate. it traveled approx 30m to the impact area. that was within 3-4 seconds. when i have looked up, it had already hit. it's why you see no input in either joystick as i had no time to react. if it was 60m away, I would have had maybe a few more seconds? And this is assuming it's at the hit speed of 15+km/h. i'm guessing it would accelerated to max P-mode speed which i think is 30+km/h. So maybe an extra 2 seconds if I was at 60m? If it had cleared the roof, it would have been a rogue projectile flying across the city. Now, I could have possibly raised it to 300m altitude to clear all max city structures but then i'm in violation of the drone rules. It hit the building and it hit nobody when it fell from the air. So maybe it was the best case scenario for the malfunction.

You can look at your flight here in the HD player.
It will show all on screen message and controller input.
It's good for looking at our flights.[url=https://app.airdata.com/share/raVPpb]Airdata HD player.[/url]Under Notifications.

fans19db8551 Posted at 6-30 09:10
thanks for the info.
Actually on my screen, the gps never turns 1 bar and red. the flight record also is the same. that's what perplexes me the most is all the hidden warnings in the flight log text that the user cannot see.
I promise you there was no breeze to carry the drone. it wasn't hovering in atti. It decided to bank sideways in an accelerated rate. it traveled approx 30m to the impact area. that was within 3-4 seconds. when i have looked up, it had already hit. it's why you see no input in either joystick as i had no time to react. if it was 60m away, I would have had maybe a few more seconds? And this is assuming it's at the hit speed of 15+km/h. i'm guessing it would accelerated to max P-mode speed which i think is 30+km/h. So maybe an extra 2 seconds if I was at 60m? If it had cleared the roof, it would have been a rogue projectile flying across the city. Now, I could have possibly raised it to 300m altitude to clear all max city structures but then i'm in violation of the drone rules. It hit the building and it hit nobody when it fell from the air. So maybe it was the best case scenario for the malfunction.

Hi fans19db8551
I really feel it for you. I cannot remember the last time I have been on this forum. I saw your post I have a mavic pro first gen two years now the novelty has worn off I fly now when doing film production I remember my first close flyaway I will never forget that day. some advice from a novice when your mavic is repaired and returned back to you always do a test on your compass and IMU before any flight. I know the pros say you should not need to do this but I always do when I fly my mavic in different locations also try not to take off around trees always try and take off in open spaces. I once read somewhere not to be afraid of crashing after I had my first crash it dented my confidence. I don't fly my drone all the time too busy but when I do I spend about 5-10 minutes after I switch on to test before lift off I think when you get your drone back nice and new you will be fine. hope it all goes well.

G_Sig Posted at 6-30 10:55
You can look at your flight here in the HD player.
It will show all on screen message and controller input.
It's good for looking at our flights.https://app.airdata.com/share/raVPpb]Airdata HD player.[/url]Under Notifications.

This flight record player seems to be a little better than the other one. I just wanted to make clear that the notifications that pop up on this airdata player is not the same notifications that the user sees on their smartphone.
I see the notifications which show in the Flight Record in the Go app. In my Youtube link, you can skip to about 8:20 timestamp.

Cole1 Posted at 6-30 11:16
Hi fans19db8551
I really feel it for you. I cannot remember the last time I have been on this forum. I saw your post I have a mavic pro first gen two years now the novelty has worn off I fly now when doing film production I remember my first close flyaway I will never forget that day. some advice from a novice when your mavic is repaired and returned back to you always do a test on your compass and IMU before any flight. I know the pros say you should not need to do this but I always do when I fly my mavic in different locations also try not to take off around trees always try and take off in open spaces. I once read somewhere not to be afraid of crashing after I had my first crash it dented my confidence. I don't fly my drone all the time too busy but when I do I spend about 5-10 minutes after I switch on to test before lift off I think when you get your drone back nice and new you will be fine. hope it all goes well.

thank you for the kind words. I believe that is sound advice.

The ironic part was that I wanted to take photo of a new mall across the street. It was the grand opening day and it will feature Singapore's first DJI owned store rather than an authorized drone shop. I was going to meet up some friends from our DJI group to see the new store. The store was tiny! Smaller than my lift off space hahaha. Double disappointment on that day lol

The airdata rendition of your data does indeed show what happened in more detail  - compass errors just after you had taken off. I'm not sure if Android Go4 app is exactely the same in error reporting as the iOS version - but it does seem that DJI could/should aggregate the error calls over a given time-slice, such that, if like you had, over 80 error reports in a couple of seconds that the drone is automatically safe landed. Because   these errors were so quick there is no way you would have been able to see them in a context - and understand the risk of continuing the flight. I image you would also have been looking at the drone and not the screen at exactly that time anyway. DJI should add 'Multiple Compass Errors detected - land immediately!' as an on screen error warning maybe?!

fans19db8551 Posted at 6-28 02:01
Thank you for your prompt response. I just sent an Email from the Support Page. There isn't Online support for the Singapore market so I assume that's the best way.

I see the email support team keeps following up your email, please follow the instruction and provide us the required info, hope the accident reason will be figured out soon.

Yes, the email support has been very good and even replying on the weekends.
They have deemed it a "non pilot error" and the Mavic currently in the mail to HK for repair. I don't mind paying the shipping with all things considered.

I do appreciate all the responses in this thread as I think everyone is very curious on why this happened. I don't think there is something entirely conclusive.
But there are things to learn as always. I don't want to just dismiss entirely as a random event even if it could be.

The best suggestions I have learned have been
1) UAV app. Wow what a great suggestion and app. I almost feel it should be integrated within the Go app. I've been monitoring it occasionally and have been noticing a trend. I feel like the mornings in my particular region seems to have the least amount of GPS sat available to lock on. It's possible that the 11 sats were the only ones available in that morning time. So it's better to fly after noon for my gps sats. I'm not saying that more sats would avoid this situation but it's more info and info is crucial for making the correct decisions. I will use the UAV as part of my preflight protocol now.
2) Check the compass sensors manually in the settings. Perhaps I could be close to borderline of a bad compass reading. It doesn't hurt to go into the settings preflight to see the raw data. A good suggestion.

Hiya,

I will add another check in wich you can see that this flight will go wrong.

As waiting for sats to lock see that the flight distance starts to increase! while still on the ground.
See the video at 9m2s, distance increasing form zero (HP just set) to 4 meter and back to 3.8 at lift off.

When HP is set, from this point the flight distance is measured. So at takeoff it should be zero and often 0.1 or 0.2 is seen.

If flight distance is increasing ( > 0.2 meter) while still on the ground, do not take off for a flight.

BTW i fully agree that DJI should give audio warning at some errorr wich are present but not seen in the app. Audio (please loud) beacuse its hard to look at the craft with one eye and one eye at the app at the same time.

cheers
JJB

Well final conclusion to this incident.
Got back the Mavic with some scratches on the lens. Not horrible gouging scratches but scratches nonetheless. They claimed it was fine by sending me a 0.3 megapixel pic of a Mavic which they claim is mine. I sent them my 4k macro lens shot footage to show them. They claimed it's the original camera because the camera wasn't on the pro forma list. They lied, I disproved them. The lens was fine when I shipped to them.
I asked for them to escalate this case and the new rep is just repeating the previous rep. They offer for me to send it back on my dime for them to look at it. So I need to pay my own money to ship again and no guarantee they will swap the camera.
It's disappointing at this point.