FLOATING OVER WATER

Joe Herrera · Apr 17, 2022

I've noticed twice now while flying / floating over a lake that when I use the controller stick to descend then let it go of the stick, the drone continues descending. I noticed it in the picture then I immediately push the stick upward to raise it. I have not noticed if the height number keeps descending when this happens since I panic when I see it descending in the video. Is it a sensor setting? Any ideas?

Yaros · Apr 17, 2022

Joe Herrera said:
Is it a sensor setting? Any ideas?

Yes, it is the sensor freaking out and messing up the readings. If you have a drone that runs on DJI Go4 there is probably a way to disable it, however you need to be careful with it disabled when landing, because it doesn't check for the area below the drone; but if you have a drone that uses DJI Fly, there is no way to disable it for now...

Yorkshire_Pud · Apr 17, 2022

In general be wary when flying low over water and be ready to give it full throttle if you even think it is descending uncommanded. I have seen my Mavic Mini do this after a speed run at a height of about 5m over water. It's better to have to descend again rather than lose the drone.
If they are not switchable you can cover the sensors with tape and that should stop them registering but I resort to just watching very closely and being ready to give it throttle.

EpicFlight · Apr 17, 2022

HOWEVER... don't mess with disabling the downward sensors without doing a lot of focused practice landing that way. Especially if you've learned and have been flying/landing with them.

All it takes is one thing to go wrong and stress you out, and you will likely completely forget that you've disabled the downward sensors, revert to reflex, and if you're descending it could result in catastrophe.

It's happened many times. Visual record of this mistake can be found on YT.

Yorkshire_Pud · Apr 17, 2022

EpicFlight said:
HOWEVER... don't mess with disabling the downward sensors without doing a lot of focused practice landing that way. Especially if you've learned and have been flying/landing with them.

All it takes is one thing to go wrong and stress you out, and you will likely completely forget that you've disabled the downward sensors, revert to reflex, and if you're descending it could result in catastrophe.

It's happened many times. Visual record of this mistake can be found on YT.

It happens if you revert to a from a 'Mavic' to Phantom 3 too, eeeeek. Lol.

Joe Herrera · Apr 17, 2022

Thanks for the feedback! This is a replacement drone since I crashed my original M2P drone last year. I think this is a minor defect I need to consult with DJI about.

Meta4 · Apr 17, 2022

Joe Herrera said:
I've noticed twice now while flying / floating over a lake that when I use the controller stick to descend then let it go of the stick, the drone continues descending. I noticed it in the picture then I immediately push the stick upward to raise it. I have not noticed if the height number keeps descending when this happens since I panic when I see it descending in the video. Is it a sensor setting? Any ideas?

Flyers get more confused about flying over water than the drone's sensors do.
What you've suggested doesn't make any sense or you haven't explained it well.
Your drone should not continue descending when the sticks are centred, regardless of whether you fly over land or water.
Post your recorded flight data from a flight where you thought this was happening and we can look into what actually happened.

Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report of the flight.
Come back and post a link to the report it gives you.
Or .. just post the txt file here.

vindibona1 · Apr 18, 2022

Flying low over water is tough and treacherous. There are many reports of unintended water landings.

EpicFlight · Apr 19, 2022

vindibona1 said:
Flying low over water is tough and treacherous. There are many reports of unintended water landings.

Yes indeed... This footage was a challenge. No getting in position and just hovering. constant throttle, pitch, and pitch input to stabilize altitude and position.

But worth it...

(If you don't want to calm yourself with this entire video, go to 1:45 and imagine the fun the FC is having with the VPS and IR sensors on the bottom...)

Azarov · Apr 21, 2022

I didn't experience such technical issue with Mavic 2 Pro, floating over water on a low altitude.
The lowest was 20m AMSL
I also realised that the pattern of a surface underneath is randomly changed.
There is a DJI recommendation not to fly over uneven/irregular surface like stretched painted roof.

Chip · Apr 22, 2022

EpicFlight said:
Yes indeed... This footage was a challenge. No getting in position and just hovering. constant throttle, pitch, and pitch input to stabilize altitude and position.

But worth it...

(If you don't want to calm yourself with this entire video, go to 1:45 and imagine the fun the FC is having with the VPS and IR sensors on the bottom...)

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That is very nicely done, calming, beautiful especially if you like oceans. Is that in Monterey? Perfect audio too btw.

Azarov · Apr 22, 2022

I've got another idea, switch off sensors!
You will need to control the wind speed and direction though.

Meta4 · Apr 22, 2022

Azarov said:
There is a DJI recommendation not to fly over uneven/irregular surface like stretched painted roof.

There's nothing wrong with flying over surfaces like that.
You just can't expect the VPS sensors to lock onto them.

Azarov said:
I've got another idea, switch off sensors!

Great idea, but DJI haven't given that option for drones that use the Fly app.

EpicFlight · Apr 22, 2022

Chip said:
That is very nicely done, calming, beautiful especially if you like oceans. Is that in Monterey? Perfect audio too btw.

Seacliff State Beach, Aptos CA. Near Santa Cruz, North Monterey Bay.

Mohawk · May 29, 2022

EpicFlight said:
Yes indeed... This footage was a challenge. No getting in position and just hovering. constant throttle, pitch, and pitch input to stabilize altitude and position.

But worth it...

(If you don't want to calm yourself with this entire video, go to 1:45 and imagine the fun the FC is having with the VPS and IR sensors on the bottom...)

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I got this shot totally unplanned.
Near Lighthouse Point, Santa Cruz,CA

Joe Herrera · Jun 2, 2022

Flew my M2P again over a small lake and discovered the drone will continue to descend when going straight down and releasing the joystick. I forgot to look at the height meter on the RC but I had the drone in my sight and saw it continued to descend after releasing the stick. If I descend at an angle, it stops and does not continue downward. The problem is the 90 degree angle descent. Have yet to consult with DJI.

EpicFlight · Jun 2, 2022

Don't contact DJI... This is a well-known phenomenon.

VPS was getting confused. Happens over water, especially calm surface, all the time. There's a warning in the manual about this.

Joe Herrera · Jun 2, 2022

The lake I was flying over was calm. I am land locked where I live so the one time last year I was able to fly the drone over the water at a Florida beach, I did not have the descending problem but that was the original M2P I bought not the replacement. Do other DJI drones have this problem?

EpicFlight · Jun 2, 2022

Calm water was the problem. All drones that use visual means for positioning will have this problem, which is most, not just DJI.

This doesn't occur if the surface is churning from wind, activity on the lake, etc. that creates visual texture to the water surface, so that changes from frame to frame can show movement.