Mavic 2 Pro Crashed into the sea without apparent reason

sar104 · Sep 10, 2019

Isaino said:
Thank you for your deep analysis @Meta4 & @sar104.

I've attached the DAT file hoping this will bring more information.

@BudWalker thank you for your help, do you know where the propulsion loss could come from ?

I was thinking maybe it could come from the propeller but they were all in perfect condition and I did a 20min flight the day before the crash without facing any issue.

I will try to open a case on the DJI website to see if it can go under warranty, thank you all for your help.

Definitely propulsion:

You can see the left front motor speeds up at 302 seconds, but the aircraft rolled left. The problem continues, and gets worse, with the FC eventually requesting full power from that motor. My guess is that the front left prop actually broke in flight, initially leading to partial thrust and later breaking more completely. Were these OEM props?

sar104 · Sep 10, 2019

sky_eye said:
Isaino, sorry you lost your bird there. It saddens me even more that DJI still havent fixed this problem, after probably 100's now of similar crashes reported on the forums, starting way back in previous Phantom generations! In 2017 I lost my P3pro in almost exact fashion. The app reported IMU and interference issues, then in the logfile it went out of GPS to ATTI mode, and spiralled into the ground at a reported 100ft/s. (I was filming an offroad race 200km from home if I didnt bring my MP1 along as well it would have been a woeful wasted day.) Geographically totally opposite - 1000km inland, very dry country (Botswana), no other drones around etc. IMHO this really is an inherent, latent firmware issue in a part of the AC firmware (navigation?) suite that hasnt been touched over the model generations. I would suggest some very direct questions to DJI Support, and even a warranty claim for what is conceivably a known problem.

Except this event bears absolutely no relation to what you are describing.

InvisibleName · Sep 10, 2019

sky_eye said:
Isaino, sorry you lost your bird there. It saddens me even more that DJI still havent fixed this problem, after probably 100's now of similar crashes reported on the forums, starting way back in previous Phantom generations! In 2017 I lost my P3pro in almost exact fashion. The app reported IMU and interference issues, then in the logfile it went out of GPS to ATTI mode, and spiralled into the ground at a reported 100ft/s. (I was filming an offroad race 200km from home if I didnt bring my MP1 along as well it would have been a woeful wasted day.) Geographically totally opposite - 1000km inland, very dry country (Botswana), no other drones around etc. IMHO this really is an inherent, latent firmware issue in a part of the AC firmware (navigation?) suite that hasnt been touched over the model generations. I would suggest some very direct questions to DJI Support, and even a warranty claim for what is conceivably a known problem.

Can’t see how this has any relevance to the OP’s issue

Isaino · Sep 11, 2019

Hello Everyone,

I have some good news. I contacted DJI and opened a case and they did confirm a warranty issue.

I really feel relieved because they propose me to send a new drone even if I couldn't recover the crashed one. I would like to thank you all again for your help ? Thumbswayup

If you're still interested in this case I've uploaded a video of the crash. I was filming the sunrise with my camera at the same time. I had to crop a lot in the video so the quality is not so good but I've circled in red the drone. We can see that the drone start to lose altitude at 25sec with a very strong angle.

Drone Crash 09-09-2019.mov

drive.google.com

MAGA · Sep 12, 2019

Isaino said:
Thank you all for your answers ! I’m amazed by the reactivity on this forum, I need to come here more often ?

So let me try to add as much info as possible:
- I didn’t restart the drone between the two calibrations but everything looked OK after the second calibration.
- I didn’t have a lot of wind during the flight, I couldn’t even feel a breeze.
- I saw that the auto landing turned on but the drone went out of control at 5:02 at 5:20 the drone was already uncontrollable and slowly falling in spiral. I probably panicked and hit the auto landing when trying to control the drone but nothing was working. You can see on the log that the drone is already having a very strange behaviour whiteout the auto landing activated and without any instruction from the remote control.

Do you think I have a chance to make the DJI warranty work ? Or is it an operator mistake? I don’t understand what I did wrong.

Try and get them to pay at least you can get a reduction in cost

MAGA · Sep 12, 2019

Isaino said:
Hello Everyone,

I have some good news. I contacted DJI and opened a case and they did confirm a warranty issue.

I really feel relieved because they propose me to send a new drone even if I couldn't recover the crashed one. I would like to thank you all again for your help ?

If you're still interested in this case I've uploaded a video of the crash. I was filming the sunrise with my camera at the same time. I had to crop a lot in the video so the quality is not so good but I've circled in red the drone. We can see that the drone start to lose altitude at 25sec with a very strong angle.

Drone Crash 09-09-2019.mov

drive.google.com

Yeahhh

MAGA · Sep 12, 2019

No

Isaino said:
Hello Everyone,

I have some good news. I contacted DJI and opened a case and they did confirm a warranty issue.

I really feel relieved because they propose me to send a new drone even if I couldn't recover the crashed one. I would like to thank you all again for your help ?

If you're still interested in this case I've uploaded a video of the crash. I was filming the sunrise with my camera at the same time. I had to crop a lot in the video so the quality is not so good but I've circled in red the drone. We can see that the drone start to lose altitude at 25sec with a very strong angle.

Drone Crash 09-09-2019.mov

drive.google.com

No Explosion?

Van Shteffy · Sep 14, 2019

Paul2660 said:
And there was a lot of miss leading info listed about magnetic interference issues. It’s still possible he had the message due to the fact he moved over 30 miles or it had been 30 days. I realize the drone was auto landed.

No I did not look at the flight data. I answered a question he had in the post about magnetic interference.

Whatever.

Paul C

Which button is the auto land button? Thanks

Mapleman231 · Sep 14, 2019

Dji is awesome!!!

MN_Jack76 · Sep 15, 2019

I had the same thing happen to my Mavic Pro. It was flying normally and I had calibrated the compass before take off. All of the sudden it started spiraling and crashed. I uploaded all of my data to this website and no one could explain what happened. The best guess was a bird strike at night. Here is the link to my post: Mavic Pro Spiraled out of the sky!

sar104 · Sep 15, 2019

MN_Jack76 said:
I had the same thing happen to my Mavic Pro. It was flying normally and I had calibrated the compass before take off. All of the sudden it started spiraling and crashed. I uploaded all of my data to this website and no one could explain what happened. The best guess was a bird strike at night. Here is the link to my post: Mavic Pro Spiraled out of the sky!

This event is somewhat similar to yours, where the conclusion was that the most likely cause was partial prop loss/damage.

Paul2660 · Sep 15, 2019

Van Shteffy said:
Which button is the auto land button? Thanks

Only way I know to select a auto land is to select it from the main DJIGO4 screen. Same area of screen where the take off icon is before take off.

I have never selected auto landing. Prefer to control it myself.

You can also get into a auto landing sequence if you get to a certain remaining percentage of your battery. On my M2 Pro this kicks in around 12 percent remaining. Note you can’t cancel this auto landing once it reaches percentage where it kicks in but you can defeat it with slight left stick upwards pressure.

Paul C

JAW · Sep 15, 2019

p.58:

Paul2660 · Sep 15, 2019

You can’t abort a auto landing which is started due to low critical battery level Just want to make sure that’s clear. All you can do is keep stick pressure on left stick upwards as soon as you let off pressure auto landing will start again.

GadgetGuy · Sep 15, 2019

Paul2660 said:
You can’t abort a auto landing which is started due to low critical battery level Just want to make sure that’s clear. All you can do is keep stick pressure on left stick upwards as soon as you let off pressure auto landing will start again.

During auto land due to critical battery, you still have stick control in every direction, including ascension. However, as you point out, it will start descending, without any stick input. Ascension speed is lower than normal, so best to gain whatever altitude you need to clear any obstacles on the remaining path back to you before it enters the critical auto land state. Mine is set as low as possible at 10%, with the 15% being the warning level. I make sure to elevate before reaching 10%, knowing I can still ascend thereafter if needed, especially during the hand catch, to make sure it remains above me at all times.

Paul2660 · Sep 15, 2019

You are correct, I was not clear. You can still fly it, but if you don't keep upwards stick pressure, it will land on you, even if you try to fly it. My point was that the key is to keep upward stick pressure or the drone will land on you no matter what you do. During the landing, you can move it, go forward, backwards, yaw it, etc but it will start descending if you take the left stick up pressure off. I feel many folks may be getting into trouble by not understanding this, and all should attempt to fly it when inside the critical battery range (where you know you can safely control the drone). The first time this happens to anyone it's a bit of a shock and can easily cause a crash or an auto landing in an bad spot.

GadgetGuy · Sep 15, 2019

Paul2660 said:
You are correct, I was not clear. You can still fly it, but if you don't keep upwards stick pressure, it will land on you, even if you try to fly it. My point was that the key is to keep upward stick pressure or the drone will land on you no matter what you do. During the landing, you can move it, go forward, backwards, yaw it, etc but it will start descending if you take the left stick up pressure off. I feel many folks may be getting into trouble by not understanding this, and all should attempt to fly it when inside the critical battery range (where you know you can safely control the drone). The first time this happens to anyone it's a bit of a shock and can easily cause a crash or an auto landing in an bad spot.

Aside from your useful insight, the fact that you can actually still ascend is what most are also completely unaware of, to give themselves more vertical clearance for the safest landing. It's one thing to be able stop descent, but it's quite another to still be able to ascend. The ability to ascend and the ability to stop the descent both end when any single cell voltage drops below 3.0V. Then, and only then is it going to descend no matter what you do, but you still have full lateral control after that.

If more people knew about these undocumented capabilities during so called "forced" Auto Land, there would be less loss of aircraft over water, and fewer crashes. I almost never land unless the battery is below 10%, so I know exactly what you are talking about, practicing flying and landing below 10%. I have even actually landed well below 0%. You still have about 2 minutes of flight time below 0% on the Mavic 2. Not for the faint of heart, but it can save your drone!