I just crashed my Mavic 2 Pro

[AroundTheWorld]

Hello,

I just crashed my Mavic 2 pro and I was wondering if you could help me to understand what happened.

I was on a hike and I brought the drone with me. I flew it quite a few time during the walk and I landed it with a 15 % battery left. On the way back to the car, I saw an amazing viewpoint and I absolutely wanted to fly it one more time there in order to film what could have been "the best shot" of the hike. I was standing on a cliff and the purpose was to record myself on the left side of the frame while the drone would come closer and reveal the landscape in front of me. It should have lasted a few seconds only and I didn't plan to fly it further than 5 meters away of me.

While in the air, I got a low battery warning with the drone telling me that it would start a "return to home". I was expecting that and I usually often ignore the message and keep the control over the drone since I have always been able to land it safely by myself.

But not this time. As I was recording my shot, I ignored the return to home warning but I saw that the drone was loosing altitude anyway without any action of me. At that time, It was still flying over the canyon and since the ground was extremely steep, I didn't want to land it there. I flew it back to me but as the drone was still descending, it crashed in the cliff.

I was able to recover it and I will send it to DJI now. The drone just crashed 2 meters in front of me while I still had 10%of the battery charge remaining. If I could have kept the control of the drone , it wouldn't have crashed. I know that I should have not flew it one last time but it's done now. I just have 2 questions :

Could you guys help me to understand why the drone started to descend while I asked the Mavic to ignore the return to home procedure? Is there a "red line" that you cannot cross and who could explain why the drone was loosing altitude anyway?

Why the Mavic didn't stop in front of the cliff? Are the sensors deactivated when you got a low battery warning?

Thanks for your help

 

[msinger]

Could you guys help me to understand why the drone started to descend while I asked the Mavic to ignore the return to home procedure?

It likely reached the critically low battery level and started auto landing. If that's what happened, that auto landing cannot be cancelled.

Check out your TXT flight log to see if it explains what happened. You can upload and view it online here. If you'd like other people to review and comment on your flight log, then please post a link back here after you upload it.

 

[AroundTheWorld]

It likely reached the critically low battery level and started auto landing. If that's what happened, that auto landing cannot be cancelled.

Check out your TXT flight log to see if it explains what happened. You can upload and view it online here. If you'd like other people to review and comment on your flight log, then please post a link back here after you upload it.

Thanks for your quick reply! Aww I was not aware of this. As I was always able to keep the control of the drone when I canceled the RTH procedure, I thought that I would still be able to make it there, not matter the low battery level. I didn't know you could not cancel the auto landing once passed a critically low level of battery charge. I just learned something too late.

Where can I find the TXT flight log?

 

[msinger]

Where can I find the TXT flight log?

See the instructions at the bottom of this page.

 

[MaxHam]

Thanks for your quick reply! Aww I was not aware of this. As I was always able to keep the control of the drone when I canceled the RTH procedure, I thought that I would still be able to make it there, not matter the low battery level. I didn't know you could not cancel the auto landing once passed a critically low level of battery charge. I just learned something too late.

Where can I find the TXT flight log?

You may also want to see the manual about RTH when the drone is less than 5m from you.
In that case there is no RTH - it just lands where it is.

 

[Paul2660]

You can’t cancel an auto landing at low battery, but you can apply left stick pressure, UP, and defeat it. As long as you apply stick pressure you can fly the drone and land it where you want to.

Anyone who flys should practice this, in a safe spot as you never know when you may run into a problem and need to push the limits.

My M2 Pro is set to the lowest critical battery level I can set it to in the SC, 10%, however it will start an auto landing in the 14 to 12% range. Again I can’t defeat this, I can kill the RTH that starts, but the auto landing will continue.

Anyone flying one of these products needs to make sure they understand that if the drone is in sight, and within 100 to 200 feet and an auto landing starts, don’t panic,, apply stick pressure and continue to land manually where you took off from. As soon as you let off the stick pressure, auto landing will start again. Takes a few test flights, but it’s still good to know.

Especially in this case, OP appears to have taken of with 15% of remaining battery, drone went into auto landing, and he more than likely could have kept upwards stick pressure on the drone and made it back.

Paul C

 

[AroundTheWorld]

Here is the log:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

So from what I can read, it appears that obstacle avoidance are turned off when flying in low battery level.


What I don't understand is how I was able to get to a speed of approximately 18 mph in 2 or 3 meters only, just before the crash?

I never fly that fast to allow proper recording and I have never activated the sport mode yet.

It's just like if the speed was increased once I got the critical battery warning. I would not have been able to avoid the crash at such a high speed.

Though

 

[AroundTheWorld]

You can’t cancel an auto landing at low battery, but you can apply left stick pressure, UP, and defeat it. As long as you apply stick pressure you can fly the drone and land it where you want to.

Anyone who flys should practice this, in a safe spot as you never know when you may run into a problem and need to push the limits.

My M2 Pro is set to the lowest critical battery level I can set it to in the SC, 10%, however it will start an auto landing in the 14 to 12% range. Again I can’t defeat this, I can kill the RTH that starts, but the auto landing will continue.

Anyone flying one of these products needs to make sure they understand that if the drone is in sight, and within 100 to 200 feet and an auto landing starts, don’t panic,, apply stick pressure and continue to land manually where you took off from. As soon as you let off the stick pressure, auto landing will start again. Takes a few test flights, but it’s still good to know.

Especially in this case, OP appears to have taken of with 15% of remaining battery, drone went into auto landing, and he more than likely could have kept upwards stick pressure on the drone and made it back.

Paul C

I had to take a decision in an instant. It was a matter of a second or two and seeing that the drone started his descent, I'm not even sure that I tried to push the left stick up, I probably just tried to find a safe place to land with the right stick. But I don't understand why the drone flew so fast just before the crash.

 

[Paul2660]

Everything happens in a hurry with last few minutes. I fully understand. I also understand the thought of trying to get the best shot of the day even though battery level was low.

Was not trying to be critical and my previous post may been come across as such.

I had a similar thing happen last year and was lucky the drone auto landed ok. After watching a few videos on YouTube on pilots looking for max distance, I learned you can defeat the auto landing with the left stick by pushing it up. Just takes the slightest pressure and you can fly home.

I practiced this on several batteries down to around 4 percent with drone over landing area 2 feet up just to see how long I could defeat the auto landing. Did not want to go below 4 percent.

Defeating auto landing is not something I normally do as I try to get back before it starts. Just wanted to point out it can be done and if you can see the drone it’s possibly worth a try.

Paul C

 

[Meta4]

So from what I can read, it appears that obstacle avoidance are turned off when flying in low battery level.

The message reads: Obstacle Avoidance will be disabled in landing.
You see that at any battery level, not just at critical low battery level.

What I don't understand is how I was able to get to a speed of approximately 18 mph in 2 or 3 meters only, just before the crash?
I never fly that fast to allow proper recording and I have never activated the sport mode yet.

You held the right stick full back from 0:52.2 until 0:54.6.
That was enough to cause that acceleration.

 

[Kilrah]

What I don't understand is how I was able to get to a speed of approximately 18 mph in 2 or 3 meters only, just before the crash?

I never fly that fast to allow proper recording and I have never activated the sport mode yet.

18mph is a normal speed in P mode.
It accelerated because you told it to, you had the stick pretty much in the corner, probably panicking and doing random stuff, potentially confusing the directions and which input to give.

You indeed did not use the throttle stick to prevent it from going down.

 

[Meta4]

What I don't understand is how I was able to get to a speed of approximately 18 mph in 2 or 3 meters only, just before the crash?

You pulled the right stick back at 62 feet from home.
You released it at 34 feet from home.

 

[AroundTheWorld]

Everything happens in a hurry with last few minutes. I fully understand. I also understand the thought of trying to get the best shot of the day even though battery level was low.

Was not trying to be critical and my previous post may been come across as such.

I had a similar thing happen last year and was lucky the drone auto landed ok. After watching a few videos on YouTube on pilots looking for max distance, I learned you can defeat the auto landing with the left stick by pushing it up. Just takes the slightest pressure and you can fly home.

I practiced this on several batteries down to around 4 percent with drone over landing area 2 feet up just to see how long I could defeat the auto landing. Did not want to go below 4 percent.

Defeating auto landing is not something I normally do as I try to get back before it starts. Just wanted to point out it can be done and if you can see the drone it’s possibly worth a try.

Paul C

Don't worry I fully understood that you were not critical it just makes me even mad on myself to see that I could have avoid the crash if I would have pushed the left stick up. It looks so simple and logical that I even didn't think about doing it on that critical situation.

 

[mharvey65]

Do you have a video of this flight?

 

[AroundTheWorld]

The message reads: Obstacle Avoidance will be disabled in landing.
You see that at any battery level, not just at critical low battery level.

You held the right stick full back from 0:52.2 until 0:54.6.
That was enough to cause that acceleration.

They should clearly note when obstacle avoidance is disabled cause I'm sure that it confuses lots of people who probably think that they are always activated no matter the situation.

 

[AroundTheWorld]

Do you have a video of this flight?

It should be on my memory card yes. I will probably try to upload somewhere when I will get a computer. I'm still on vacations.

Talking about that: do you think it would be possible for DJI to send me the replacement drone there instead of my home?

 

[Kilrah]

They should clearly note when obstacle avoidance is disabled cause I'm sure that it confuses lots of people who probably think that they are always activated no matter the situation.

They do...

 

[RayOZ]

It should be on my memory card yes. I will probably try to upload somewhere when I will get a computer. I'm still on vacations.

Talking about that: do you think it would be possible for DJI to send me the replacement drone there instead of my home?

If you have DJI Care Refresh, you have to send it from your home country and they will return it to your home address.

 

[sar104]

Don't worry I fully understood that you were not critical it just makes me even mad on myself to see that I could have avoid the crash if I would have pushed the left stick up. It looks so simple and logical that I even didn't think about doing it on that critical situation.

In case it helps with visualizing the event:



And in terms of the aircraft's horizontal motion:





But, apart from losing track of your stick inputs at the end, the issue was entirely created by launching at just 11% battery. That's a guaranteed recipe for disaster, since the minimum value for critical battery autoland at any height is 10%.

 

[AroundTheWorld]

In case it helps with visualizing the event:

View attachment 78399

And in terms of the aircraft's horizontal motion:

View attachment 78401

View attachment 78400

But, apart from losing track of your stick inputs at the end, the issue was entirely created by launching at just 11% battery. That's a guaranteed recipe for disaster, since the minimum value for critical battery autoland at any height is 10%.

Thanks for your post. I agree with your conclusion. But since I flew dozens of time in a low battery situation, I thought it would be okay. I just didn't know about the autoland at 10% since I didn't fly below that mark until now. Shame on me.