Lost Drone Not Sure Why

bkushner · Sep 28, 2020

So today I was flying on the Delaware River as I've done thousands of times. I lost signal as I've done a ton of times and when it finally came back the drone was landing over the water. There was no indication as to why it was landing. I had plenty of battery. There were no NFZ nearby etc etc. When I regained control after loss of signal I could not do anything, the drone was at 25 feet and landing and SPLASHDOWN.

I fly Litchi and here is my log file. Obviously with Litchi the details are not thorough like DJI Go App.

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

One thing Air Data shows is a compass thing before the loss. Not sure what that means. See image.

Any thoughts would be appreciated.

Thomas B · Sep 28, 2020

Did you hover above T.O. Point until the drone told you the home point was registered?

boblui · Sep 28, 2020

bkushner said:
.... it finally came back the drone was landing over the water...... the drone was at 25 feet and landing and SPLASHDOWN.

Do you mean the drone managed to come back and descended into the water 25 ft in front of you ? This is not indicated in the flight log which ended when the drone was still more than 9000 ft away from the home point.

bkushner · Sep 28, 2020

Thomas B said:
Did you hover above T.O. Point until the drone told you the home point was registered?

Yes ...You can see the H on the map from where I took off from.

bkushner · Sep 28, 2020

boblui said:
Do you mean the drone managed to come back and descended into the water 25 ft in front of you ? This is not indicated in the flight log which ended when the drone was still more than 9000 ft away from the home point.

No I lost signal down river and when signal returned the drone was flying towards home then I watched it stop and descend.

boblui · Sep 28, 2020

The last record of the flight log indicates that the drone was at a height of 25 ft. It was in sport mode and full-down throttle was applied. It seems that the ditching was commanded by stick inputs.

bkushner · Sep 28, 2020

boblui said:
The last record of the flight log indicates that the drone was at a height of 25 ft. It was in sport mode and full-down throttle was applied. It seems that the ditching was commanded by stick inputs.

View attachment 114015

Not sure why stick down unless controller malfunctioned. I was pushing up on the stick trying to raise..then I clicked on HOME button and then disconnect. I've been getting stick errors when starting controller sometimes. I didn't get it this flight.

boblui · Sep 28, 2020

bkushner said:
Not sure why stick down unless controller malfunctioned. I was pushing up on the stick trying to raise..

The right stick was fully up but that controls the forward/backward speed. Is it possible that you mixed it up for some reasons ? It has occurred to my brain occasionally.

Phantomrain.org · Sep 28, 2020

bkushner said:
So today I was flying on the Delaware River as I've done thousands of times. I lost signal as I've done a ton of times and when it finally came back the drone was landing over the water. There was no indication as to why it was landing. I had plenty of battery. There were no NFZ nearby etc etc. When I regained control after loss of signal I could not do anything, the drone was at 25 feet and landing and SPLASHDOWN.

I fly Litchi and here is my log file. Obviously with Litchi the details are not thorough like DJI Go App.

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

One thing Air Data shows is a compass thing before the loss. Not sure what that means. See image.

Any thoughts would be appreciated.

View attachment 114010

This is interesting as it almost sounds like what just happened to me on the Air 2 where the Remote landing changed the Home Point on me by resetting itself where I remote landed. I wonder if your disconnect reset your home point. ? Now I got to test the mavic 2 on the remote landing .

How far was the dis connect from where it landed in the River. ?

bkushner · Sep 29, 2020

boblui said:
The right stick was fully up but that controls the forward/backward speed. Is it possible that you mixed it up for some reasons ? It has occurred to my brain occasionally.

Surely that's possible but i let go of sticks around 15 feet and pushed return to home so if it was the sticks it should have hovered at 15 feet.

bkushner · Sep 29, 2020

Phantomrain.org said:
This is interesting as it almost sounds like what just happened to me on the Air 2 where the Remote landing changed the Home Point on me by resetting itself where I remote landed. I wonder if your disconnect reset your home point. ? Now I got to test the mavic 2 on the remote landing .

How far was the dis connect from where it landed in the River. ?

That's possible but never happened before. Also if you look at map it shows the home point as exactly where I took off from.

boblui · Sep 29, 2020

bkushner said:
i let go of sticks around 15 feet and pushed return to home so if it was the sticks it should have hovered at 15 feet.

A few things worth noting :

1) The drone was in sport mode so obstacle avoidance was off.
2) The drone was going down and forward at maximum speed so it would continue to fly for some distance before it could come to a stop.
3) The height of 15 ft is mainly the reading of the barometer which can drift slowly over time due the change in atmospheric pressure. E.g. I have seen the height reading of my M2P off by about 10 ft after a flight so your drone might actually be closer to the water than 15 ft at that moment.

Giovanni · Sep 29, 2020

From the park you took off to the battleship New Jersey is 2.99 miles. Granted, you were just shy of that. I used to like that area until I noticed how low those helicopters are in that area...like 150ft...

Meta4 · Sep 29, 2020

bkushner said:
Not sure why stick down unless controller malfunctioned. I was pushing up on the stick trying to raise..then I clicked on HOME button and then disconnect. I've been getting stick errors when starting controller sometimes. I didn't get it this flight.

Controller malfunction might be a possibility.
The data shows the left stick pulled hard down from 7:13.5 (alt = 190 ft) and held down until end of data.
You can see the joystick positions in the Phantomhelp report.
The drone was getting the signal to descend and that's what it did.

Goin Up · Sep 29, 2020

If you're using Litchi, why are you in sport mode instead of waypoint (P)? It would have returned and landed exactly at the point of takeoff w/o any input from you.

bkushner · Sep 29, 2020

Goin Up said:
If you're using Litchi, why are you in sport mode instead of waypoint (P)? It would have returned and landed exactly at the point of takeoff w/o any input from you.

I use sportsmode for more speed.

bkushner · Sep 29, 2020

Meta4 said:
Controller malfunction might be a possibility.
The data shows the left stick pulled hard down from 7:13.5 (alt = 190 ft) and held down until end of data.
You can see the joystick positions in the Phantomhelp report.
The drone was getting the signal to descend and that's what it did.

I was a 190 and when I was returning I was hitting wind so I go lower to 50-60 to return without as much wind resistance.

Goin Up · Sep 29, 2020

bkushner said:
I use sportsmode for more speed.

you get a lot of blurry videos and pictures that way?

bkushner · Sep 30, 2020

Thanks everyone for trying to help. Again flying over water it's a risk I take and since it's clearly not a device issue I have no blame for DJI. With that said I'm in a conundrum as to what to get next.

I have batteries and accessories of course for the Mavic 2 Pro. However, I've thought about Mavic Air 2.

I can get a refurb M2P for $1279 - and I'm good to go....or I can get into a new system the Mavic Air 2 for $999 and be good to go. With the Mavic 3 around the corner I also have to keep that in mind. So if you were me would you do the M2P or the MA2?