Drone dropped from sky over ocean

[Tilt2K]

Hi there,

New poster but long time lurker and was hoping you guys could help me figure out what happened to me drone.

In short, I went for a short flight around a harbour in Greece. Conditions were good although maybe a little warm out and I've flown it in much hotter conditions. After 3 mins the drone just dropped from the sky. No warnings on the app. No birds that I could see. Nothing, Almost like it had been shot from the sky. It just plummeted into the sea. It's the first drone I've lost after owning a few Phantoms and two Mavics. Obviously I'm gutted. I'm going to hire scuba gear tomorrow to try and find it as it can't be that deep and I can dive. However I'd really like to know what happened. I'm obviously concerned that my drone just dropped. In a way I'm glad it was the ocean and not over land where it could have hurt someone.

The flight record is attached but I can't find a .dat

Any pointers on what went wrong would be hugely appreciated.

Many thanks

 

[Deleted member 103366]

the phantomhelp page DJI Flight Log Viewer - PhantomHelp.com

 

[Phantomrain.org]

Hi there,

New poster but long time lurker and was hoping you guys could help me figure out what happened to me drone.

In short, I went for a short flight around a harbour in Greece. Conditions were good although maybe a little warm out and I've flown it in much hotter conditions. After 3 mins the drone just dropped from the sky. No warnings on the app. No birds that I could see. Nothing, Almost like it had been shot from the sky. It just plummeted into the sea. It's the first drone I've lost after owning a few Phantoms and two Mavics. Obviously I'm gutted. I'm going to hire scuba gear tomorrow to try and find it as it can't be that deep and I can dive. However I'd really like to know what happened. I'm obviously concerned that my drone just dropped. In a way I'm glad it was the ocean and not over land where it could have hurt someone.

The flight record is attached but I can't find a .dat

Any pointers on what went wrong would be hugely appreciated.

Many thanks

So at the beginning of the take off it appears you had some issues , so this could have been magnetic interference which caused the drone to struggle with the GPS until just pushing you into Atti mode and than it just got blown right down into the ocean as you might have frozen when you lost the GPS and the wind took over the drone in Atti Mode.

Others may see thing differently but the take off was not without risk.

Phantomrain.org
Gear to fly your Mavic in the Rain.

 

[Tilt2K]

Thanks for the quick reply. It always tells me to calibrate compass at start so I did. The obstacle avoidance was a boulder nearby but I was aware of it and it wasn't close other than to give a brief warning at the start. There wasn't any wind that I noticed...just clear blue sky...which it makes it all the more puzzling.

 

[Phantomrain.org]

Thanks for the quick reply. It always tells me to calibrate compass at start so I did. The obstacle avoidance was a boulder nearby but I was aware of it and it wasn't close other than to give a brief warning at the start. There wasn't any wind that I noticed...just clear blue sky...which it makes it all the more puzzling.

This may be part of the problem : The fact that you have to calibrate the compass on each flight is a Red Flag as you should not have to do that and could have been
the magnetic interference. Did you take off from a rock or grass or hand ?

 

[Tilt2K]

This may be part of the problem : The fact that you have to calibrate the compass on each flight is a Red Flag as you should not have to do that and could have been
the magnetic interference. Did you take off from a rock or grass or hand ?

I've always had to do that...I assumed it was because I travel a lot and the drone's compass needed re-calibrating a fair bit.

I took off from a flat boulder in the middle of nowhere.

 

[Phantomrain.org]

I've always had to do that...I assumed it was because I travel a lot and the drone's compass needed re-calibrating a fair bit.

I took off from a flat boulder in the middle of nowhere.

No more boulders for you, from now on you find Grass, mud, sand, straw, or some Lilly pad , and you will most likely be safe to fly.

As as general rule if the drone is asking you to re calibrate what you should do is shut down the drone and controller and move to another location and dont try to force the Compass to Calibrate when it really does not want to.

Phantomrain.org
Gear to fly in the rain.

 

[slup]

So at the beginning of the take off it appears you had some issues , so this could have been magnetic interference which caused the drone to struggle with the GPS until just pushing you into Atti mode and than it just got blown right down into the ocean as you might have frozen when you lost the GPS and the wind took over the drone in Atti Mode.

Others may see thing differently but the take off was not without risk.

Phantomrain.org
Gear to fly your Mavic in the Rain.

View attachment 109356

That's not entirely correct ... the AC wasn't in ATTI mode until the very end of the flight & the compass hadn't anything to do with this.



The flight as a whole was totally healthy regarding the positioning ability ... Navhealth 5 10sec into the flight.



Instead this most probably was a prop or possibly a motor failure on front right ... when the incident starts the AC starts to rotate CCW, pitch heavily forward & roll far to the right, all indications on a lost thrust from the front right.

Here Yaw, Roll & Pitch from 144sec into the flight ...

 

[Phantomrain.org]

That's not entirely correct ... the AC wasn't in ATTI mode until the very end of the flight & the compass hadn't anything to do with this.

View attachment 109366

The flight as a whole was totally healthy regarding the positioning ability ... Navhealth 5 10sec into the flight.

View attachment 109367

Instead this most probably was a prop or motor failure on front right ... when the incident starts the AC starts to rotate CCW, pitch heavily forward & roll far to the right, all indications on a lost thrust from the front right.

Here Yaw, Roll & Pitch from 144sec into the flight ...

View attachment 109368

just so I’m clear , your saying that the prop or motor caused it to go into atti mode at the end of the flight ? Why would it loose GPS because of a prop motor Malfunction ?

 

[slup]

just so I’m clear , your saying that the prop or motor caused it to go into atti mode at the end of the flight ? Why would it loose GPS because of a prop motor Malfunction ?

The AC went from Navhealth 5 to 0 (= ATTI) 0,3sec before the log ends probably due to FC overload due to fighting all extreme AC movements in the end ... pitch angles up to 85 degrees & roll angles to nearly 170 degrees together with a rapid CCW spinn.

Can also add that ATTI is sort of a last defense mechanism for the FC ... when the FC gives up it leaves over everything to the pilot, except the height hold. If you're skilled & master ATTI it can save the day ... but with lost thrust from a broken prop or a motor failure you're out of luck ... ATTI mode doesn't make a AC drop like a rock ... windy or not.

 

[boblui]

There was very little wind. The repeated messages about not enough force and ESC error near the end of the flight with no stick input is a strong support that propulsion failure has occurred.

 

[Meta4]

just so I’m clear , your saying that the prop or motor caused it to go into atti mode at the end of the flight ?
Why would it loose GPS because of a prop motor Malfunction ?

Because the drone had fallen nearly 100 feet and rolled upside down

So at the beginning of the take off it appears you had some issues , so this could have been magnetic interference which caused the drone to struggle with the GPS until just pushing you into Atti mode and than it just got blown right down into the ocean as you might have frozen when you lost the GPS and the wind took over the drone in Atti Mode.

Others may see thing differently but the take off was not without risk.

If they can read flight data they will see it differently.
There was not even a hint of any problem with the takeoff.
It was perfectly normal.

 

[Meta4]

Any pointers on what went wrong would be hugely appreciated.

The drone was in straight level flight until 2:24.3 when it started to roll to the right, pitch down, rotate anti-clockwise and lose height.
That is characteristic of the loss of a propeller or motor.

 

[Phantomrain.org]

The drone was in straight level flight until 2:24.3 when it started to roll to the right, pitch down, rotate anti-clockwise and lose height.
That is characteristic of the loss of a propeller or motor.

Understood but I am struggling with how the loss of prop or motor has anything to do with going into ATTI mode ?

 

[Meta4]

Understood but I am struggling with how the loss of prop or motor has anything to do with going into ATTI mode ?

At the time the drone was upside down.
It wasn't able to recMeive any satellite signals.
No GPS = Atti mode

 

[Tilt2K]

Thanks for all the help and analysis; really appreciate it. I thought possibly a propeller or motor failed as the flight seemed absolutely fine until that point. Nothing out of the ordinary and I cruised along getting some nice footage.

How can you mitigate something like a propeller failing? I'm slightly apprehensive going forward as obviously a drone randomly falling out of the sky isn't ideal.

I'm still waiting for permission to dive in the port to see if I can retrieve the drone.

 

[Phantomrain.org]

Thanks for all the help and analysis; really appreciate it. I thought possibly a propeller or motor failed as the flight seemed absolutely fine until that point. Nothing out of the ordinary and I cruised along getting some nice footage.

How can you mitigate something like a propeller failing? I'm slightly apprehensive going forward as obviously a drone randomly falling out of the sky isn't ideal.

I'm still waiting for permission to dive in the port to see if I can retrieve the drone.

Can you post the footage that you took from the controller.

 

[cheolk]

My Phantom Std 3 also suddenly dropped in to the tree.
Suddenly. I was in a park.
I paid some money to retrieve it. Now I fear my Mavic may do so again.

 

[Tilt2K]

Can you post the footage that you took from the controller.

Sure.I don't have the moment I lost control as I tend to take stills images which is what I was doing at that point.

But here's some of the video from 30 seconds before:

2020_07_31_16_38_05.mp4

1 file sent via WeTransfer, the simplest way to send your files around the world

wetransfer.com

 

[peterc4]

Mine done it back in april mate, and a few more on here since then, never got to the bottom ofi it mp2 fall out of the sky on a regular basis