Hi all,

just sank my new Mavic 2 Pro into the river. I got it about a week ago, and was learning to operate it very conservatively. I flew it mostly over a wide meadow (river bank really) in T mode, just learning the moves.

This morning, the weather was beautiful, calm, sun was just coming out so I tried recording some footage above the river. I hovered around abandoned river barges, went up high, snapped a few photos, tried a couple of reveal shots over trees revealing the barges, nothing too Sam Kolder fancy.

All was fine and well untill I decided to do a low pass under a bridge. The bridge carries road traffic plus light rail, it's about 10 meters/33 foot high above water and very wide between posts. I moved slowly forward, tilting the camera upward but at some point just under the bridge, Mavic simply lowered itself and ditched into the water.

I have to admit, I was very sad at that moment - I LOVED that drone and the footage it was capable of! And, just yesterday I got my PolarPro filters, the largest 14 pc. set  .

Any ideas what went wrong? I don't know if I'll be able to afford another drone but if I ever do - what should I have done differently? Optical avoidance got confused because of the water? Lack of my UP input on the stick, at the last moment?

Any advice appreciated!
Alex

Post your flight log and share and someone might be able to figure out what happened.

https://www.phantomhelp.com/LogViewer/Upload/

Also sounds simular to what happened in this thread - https://forum.dji.com/forum.php?mod=viewthread&tid=196459

Sorry for your loss, but dji does not recommend to fly over water and furthermore flying under a bridge that contains a high amount of metal may cause interferences...

Thanks all, I appreciate your input! Don't get me wrong, I'm not accusing anyone or anything, I'm just trying to learn from this bad experience. This is completely my fault and I take full responsibility.

Here is the uploaded flight log w. a map https://www.phantomhelp.com/LogViewer/DL7XAEFJ8W1N830AUTO1.

To much metal around, loss of gps and maybe went into ATTI mode, compass error, too close to the water for bottom sensors, in the manual it says somewhere about the height you should stay above water I think, logs will tell, so 1 of the expert guys on here will come along soon and decipher your logs for you


https://forum33.djicdn.com/data/ ... vqjcqp2jvc2a2vf.png

djiuser_VRAlyDZQM7KB Posted at 8-30 02:10
Thanks all, I appreciate your input! Don't get me wrong, I'm not accusing anyone or anything, I'm just trying to learn from this bad experience. This is completely my fault and I take full responsibility.

Here is the uploaded flight log w. a map https://www.phantomhelp.com/LogViewer/DL7XAEFJ8W1N830AUTO1.

Hi,

Had a look at your flight, ofcourse sorry for your loss.[

All looks OKE in the log. no errors. no ATTI, no interference etc.

Just before flying under the bridge : Baro height steady indicating 0.2 meters, VPS height 5.5 meters (both fluctuations of 0.1 meter = normal imo)

Under the bridge the Baro height indicating heigher values ! from 0.2 to 1.5 meter.
At the same time VPS height indicates less height. So if VPS is correct AC is dropping.
So IMO because BARO height was somehow disturbed under the bridge, the software thinks that your M2 is climbing!
Thus a correction to steer down, wich i did as it dropped into the river.

After reaching BARO height of 1.5, it started to indicate lower values, but as the drone steered down (by sw) too late to steer up (by sw) again.

See the V-z values (up | down speed ) in my chart, from -0.0 to -0.4 (thus lowering craft), at the end 1.4...so SW up steerring but too late.
(In the chart ALT = BARO)
[ DISCLAIMER = just my opinion of this mishap. If anyone thinks differently. do comment please ]

cheers
JJB

@Captain - THANK YOU for such detailed analysis, much appreciated!

I am currently training for my private pilot licence so I understand the terminology and I understand the "aviation" aspect of things. What I am lacking is the electronics part. I thought that it would never self correct unless in some sort of automatic mode, but rather, just fly straight at a steady altitude.

But now that I think of it, in the aircraft, we fly barometric altitude or (in less frequent situations) height above ground. Mavic seems to have both barometer AND some sort of electronic altitude meter. Had I known this (or maid better attention) I might have saved it.

The worst part is, in 10 days we are travelling to Amalfi coast with our camper van, of course... the best shots are now not an option anymore

You cannot turn the topward obstacle avoidance off.  Maybe a bird or a piece of paper landed on top of the drone making it go lower.

This is a good experience to learn from.  I never fly underneath things because if I lose signal it will pop up and hit what it's under.  I've instantly lost signal for any reason.

Alexander.Starbuck Posted at 8-30 03:53
@Captain - THANK YOU for such detailed analysis, much appreciated!

I am currently training for my private pilot licence so I understand the terminology and I understand the "aviation" aspect of things. What I am lacking is the electronics part. I thought that it would never self correct unless in some sort of automatic mode, but rather, just fly straight at a steady altitude.

Height is controlled by use of barometer height input, so at every height (after up or down stick) this height is the reference height.So P-GPS, Sport, Tripod etc are all automatic modes! (height by barometer, position by GPS and/or Vision systems)


My guess is that wind blowing under the bridge (venturi effect) will reduce the air pressure locally.
Lower air press means for the sensor a higher altitude, as its flying in a controlled height 'mode' the SW will bring her down.

cheers
JJB

I know the feeling, I sank my two day old P4 in a deep, fast running river.  Learn from my mistake and save everything and just buy the drone, I was so mad I threw everything away when I got home.

Hello and good day Alex. I am sorry to know what happened to your DJI Mavic 2 Pro. Since this unfortunate incident happened on said drone. I would recommend you contact our DJI support team to start up a case for the said drone at https://www.dji.com/support?site=brandsite&from=nav . We have the professional team who would do their best to find out the reason of the incident and then the corresponding resolution would be provided. We hope to hear from you as soon as possible for further assistance. Again I am sorry for what happened and thank you for your support.

DJI Stephen Posted at 8-30 08:05
Hello and good day Alex. I am sorry to know what happened to your DJI Mavic 2 Pro. Since this unfortunate incident happened on said drone. I would recommend you contact our DJI support team to start up a case for the said drone at https://www.dji.com/support?site=brandsite&from=nav . We have the professional team who would do their best to find out the reason of the incident and then the corresponding resolution would be provided. We hope to hear from you as soon as possible for further assistance. Again I am sorry for what happened and thank you for your support.

您好 Steven!

I will try and do that.

Many thanks!
Alex

Alex.Starbuck Posted at 8-30 08:36
您好 Steven!

I will try and do that.

You are very much Alex. Please keep us posted on he said issue. If you have any other inquiries or concerns with DJI. Please feel free to post it here at DJI Forum. We are here to help and support you. Thank you.

Very sorry about your loss Alex

I am really overwhelmed by great wishes and support here on the forum , thank you all! It's so nice to see that I'm not the only one "struggling" sometimes. Update for DJI Stephen - I had a chat with official DJI support, gave them all the info and they promised to file an official report and see if there is anything they can do.

Keeping my fingers crossed!

Alex.Starbuck Posted at 8-30 11:31
I am really overwhelmed by great wishes and support here on the forum , thank you all! It's so nice to see that I'm not the only one "struggling" sometimes. Update for DJI Stephen - I had a chat with official DJI support, gave them all the info and they promised to file an official report and see if there is anything they can do.

Keeping my fingers crossed!

Thank you for the additional information you have provided Alex. Please keep us posted on the said matter for us to be able to help and assist you further. Thank you.

Never nice to lose your machine. Sorry to hear about your incident.

you just got the drone and you decided to do some advanced flying? bad play but I feel for you!

It looks like you had about 5 seconds or so from the time you went under the bridge at 17 feet or so to see your altitude dropping and either get out or climb.  Being over 800 feet away probably didn't help in seeing and recognizing the peril you were in.  Interesting that the last entry notes overhead obstacle.  Not sure if it finally saw the bridge or it that was water covering it as it was going down.

bobsma Posted at 8-30 12:12
you just got the drone and you decided to do some advanced flying? bad play but I feel for you!

Well... yea. I've watched too much footage in my life and I know that the things that look best on camera are low passes, various reveal shots, tilt ups/downs, fly-overs (trees), fly-throughs... the trouble is, I forgot that those kinds of shots probably take two skilled people to operate (one for the drone, second one for the camera).

Argh... better luck next time, if there will be next time.

Sorry to hear about your loss - it doesn't take long to get attached to your drone. I hope your MP2 was insured. I lost my Spark in the water (my fault) but DJI care refresh had a refurbished to me within 4 weeks and it cost me only $AU99.

AntDX316 Posted at 8-30 04:10
You cannot turn the topward obstacle avoidance off.  Maybe a bird or a piece of paper landed on top of the drone making it go lower.

This is a good experience to learn from.  I never fly underneath things because if I lose signal it will pop up and hit what it's under.  I've instantly lost signal for any reason.

these sorts of things happened well before DJI implemented top firing sensors on consumer/prosumer drones.    usually the bottom firing VPS is to blame, water being reflective can confuse the vision positioning system into thinking its lower or higher altitude then it is.

as for what JJB is saying.. his analysis is correct however still a mystery as to why it did what it did, wasn't pulling down on the sticks to trigger a landing, and VPS should prevented the aircraft from going lower if it though it was too close.   so question is, was the VPS wrong..?  was the actual high lower than what VPS was thinking because 5 meters is plenty of alt for it to not go into the water and catch myself normally unless it was dark and bottom light was off.. hell even 3 meters should be plenty for it to catch itself if enough light.

Well that is not good very sorry.

My biggest sorry is the Italian trip thing. I am going to Naples, Amalfi and Capri island in 10 days, with my girlfriend and in a nice little camper van. Can you imagine all the shots I planned to make in those great Italian sunsets, Tuscany (along the way), then Amalfi coast? Positano would have been amazing from the air in the golden and blue hour...

But I am surprised about all the support I am getting from other members here, that is really nice and somewhat comforting in a situation like this. Thanks guys and gals!

Alex.Starbuck Posted at 8-30 21:45
My biggest sorry is the Italian trip thing. I am going to Naples, Amalfi and Capri island in 10 days, with my girlfriend and in a nice little camper van. Can you imagine all the shots I planned to make in those great Italian sunsets, Tuscany (along the way), then Amalfi coast? Positano would have been amazing from the air in the golden and blue hour...  

But I am surprised about all the support I am getting from other members here, that is really nice and somewhat comforting in a situation like this. Thanks guys and gals!

Alex, I really am so sorry for you.
I genuinely know exactly what you're going through after losing my new Mavic Pro down over the White Cliffs of Dover 2 years ago just 2 weeks after getting it

I can only give you my experience and best advice.  Your trip to Amalfi deserves a drone. Bite the bullet if you can and get yourself either a new M2 Pro or settle for the still amazing original Mavic Pro which you can get for £899 from DJI.com and even cheaper on eBay (no guarantee tho).  Learn from this mistake (we all make mistakes; it's how we learn from them that makes us better), move on and have fun.

My trip to Amalfi last year shows you why you need a drone.  You'll get one sooner or later, so just get one now if you can in time for your trip....  
And finally, check the 'personal possessions' section of your home insurance if your policy has that element. It may surprise you as it will cover all personal items against accidental damage anywhere in the world.

Cheers
Ian

Alex.Starbuck Posted at 8-30 21:45
My biggest sorry is the Italian trip thing. I am going to Naples, Amalfi and Capri island in 10 days, with my girlfriend and in a nice little camper van. Can you imagine all the shots I planned to make in those great Italian sunsets, Tuscany (along the way), then Amalfi coast? Positano would have been amazing from the air in the golden and blue hour...  

But I am surprised about all the support I am getting from other members here, that is really nice and somewhat comforting in a situation like this. Thanks guys and gals!

You could try purchasing a second hand drone, Mavic Pro can be purchased pretty cheap also Mavic air and even spark will get you some memorable shots.
Dji will or at least should offer you a 15% discount off buying just the M2 without RC.
Of course I understand budget may be a factor, just some ideas if you can afford something.
Good luck .

Sorry to know that

Very sorry to read that. The drone will mainly use GPS to hold its position and when you fly under a bridge that may prevent the GPS lock switching the drone OPTI mode. In a dark area, such as under a bridge, and with the drone above water the VPS may have become erratic and the upward sensor may not have had enough light to sense the top of the bridge temporally switching to ATTI mode - this was probably the cause of the loss. It would be similar to flying indoors in a dark room with no GPS... I hope you manage to get a replacement soon and suggest you only fly under bridges if someone is paying you a lot of cash to do so.

Mine was flying low above pavement.pressing forward only the drone lowered itself to catch the left leg and tumbled @ 20 feet taking out my gimbal and sensor. Dont know why it lowered altitude by itself like that. Now gotta send it in and hope its covered by warranty. Darnit i was haulin too and she rolled like a nascar..sad day here in iowa

I wonder if, for these kinds of flying, should everything that itls autom. be disabled? Should the drone be flown in FULL manual mode? I suppose that would be extremely difficult to operate and require much skill but that way you would know exactly what the craft is going to do (i.e. nothing, unless the operator explicitly provides the control input).

Wellsi Posted at 8-31 01:32
Alex, I really am so sorry for you.
I genuinely know exactly what you're going through after losing my new Mavic Pro down over the White Cliffs of Dover 2 years ago just 2 weeks after getting it

Stunning video.  thanks for sharing.

Alex.Starbuck Posted at 9-2 00:12
I wonder if, for these kinds of flying, should everything that itls autom. be disabled? Should the drone be flown in FULL manual mode? I suppose that would be extremely difficult to operate and require much skill but that way you would know exactly what the craft is going to do (i.e. nothing, unless the operator explicitly provides the control input).

You don't have the ability to turn off certain functions like the barometer, IMU or even GPS on the Mavic 2....  all you can do is disable the collision avoidance sensors.

djiuser_eJjxBEqBpBrD Posted at 9-1 13:50
Mine was flying low above pavement.pressing forward only the drone lowered itself to catch the left leg and tumbled @ 20 feet taking out my gimbal and sensor. Dont know why it lowered altitude by itself like that. Now gotta send it in and hope its covered by warranty. Darnit i was haulin too and she rolled like a nascar..sad day here in iowa

That is pretty much normal behavior for quad-type drones (not sure about hexa, octa etc. because I have no exp with them). When drone starts flying forward, its trust vector starts pointing a bit backward, instead of straight down, so the aircraft starts kind of slipping down-forward. To avoid this you should add trust to aircraft so it stays on the same altitude. Since DJI drones are sort of autonomous vehicles they should do it by themselves, but I guess it can happen that they can't process the environment so fast.

Alex.Starbuck Posted at 8-30 13:20
Well...  yea. I've watched too much footage in my life and I know that the things that look best on camera are low passes, various reveal shots, tilt ups/downs, fly-overs (trees), fly-throughs... the trouble is, I forgot that those kinds of shots probably take two skilled people to operate (one for the drone, second one for the camera).

Argh... better luck next time, if there will be next time.

your a good person and don't deserve this. I know this much!

I have never done a drone flight below 60 meters height  !  All these drones do fail while flying well below 10 meters height.

Dji should add way to disable completely upward and Vps sensors individually in sensors off preferences. This should be custom configuration where we could disable absolutely all sensors we want. All problems I had was because of those sensors, especially top sensor, that even when I throttle up full, it blocks me to go up.. It caused accident when I was going out thought windows.. It lowered themselves I touched windows and fallen from 10th floor at ground.. Did it about 400 times without any problems before, just because top sensor misinformation (was about 1.5-2 meters from top)  drone felt from building. Also had too many error reading on VPS.. It tried land at 25 meters altitude (Vps reading error said it was 0.3m high)..

Cant you just map one of the C buttons to disable all sensors as a toggle?

gnirtS Posted at 9-13 02:31
Cant you just map one of the C buttons to disable all sensors as a toggle?

I aways do that. I have one C button to disable sensors, but there is no option to disable using button all sensors including Vps or top sensor.. This should be custom config.. Individual option to mark what sensors would like to disable pressing c button. Would be nice add for more advancing flying.. We could do what we expect.. Not crash because error of sensors..

AntDX316 Posted at 8-30 04:10
You cannot turn the topward obstacle avoidance off.  Maybe a bird or a piece of paper landed on top of the drone making it go lower.

This is a good experience to learn from.  I never fly underneath things because if I lose signal it will pop up and hit what it's under.  I've instantly lost signal for any reason.

"topward obstacle avoidance"