Yes, Landing Protection CAN be disabled, but...

[charliebicks]

Loved this thread, still do.

Something interesting happened to my drone the other day.

I was flying over the sea, from a beach that I live nearby to. And the drone started descending and descending, and simultaneously flying in a random direction, as if it were to follow some kind of invisible current in the water. I was about 60m away from the drone, and I noticed it before it took a soft plop into the water, and so pulled the drone up.

The same behaviour repeated. I considered, that the optical component of the vision positioning system was responsible for the erratic, spontaneous behaviour.

I wished to test the limits of the infrared ToF sensors, and see if they would prevent the drone from plopping in to the sea. With baited breath I waited until the last moment I could bare - to pull away from the sea. It appeared to me on the couple of occasions that I did this test that there was no prevantative response from the infrared sensors. I tried the same test in sport mode and with opstacle avoidance turned off, but I got the same response.

I wish I had tried it with the visual positioning system turned off! Therein may have contained the issue.

 

[Zbip57]

[...] the drone started descending and descending, and simultaneously flying in a random direction, as if it were to follow some kind of invisible current in the water. I was about 60m away from the drone, and I noticed it before it took a soft plop into the water, and so pulled the drone up.
The same behaviour repeated. I considered, that the optical component of the vision positioning system was responsible for the erratic, spontaneous behaviour.

Other than during actual landing, the optical sensor will not affect the normal handling of your drone. It only comes into play when trying to hold horizontal position during hover with the control sticks centred. The optical sensor has nothing to do with vertical hold.

I have seen your posts in the other thread about your Mavic 3 misbehaving, and cannot add anything further to that because I don't have a Mavic 3 and am unfamiliar with how it behaves.

But I can say, based on how my Mavic Mini behaves, that the downward facing infrared sensors never cause the drone to descend. Regardless of how the distance to the ground underneath the drone varies (as sensed by the infrared sensor and as recorded in the flight log as VPS height), it never produces any noticeable effect at all on the Mini, unless it senses something within 0.5m (~2ft) of its underside. In that case, the drone only ever reacts by increasing its height.

You can test that for yourself (preferably not over water) by holding only slight down throttle. The drone will descend, as commanded, but only until reaching 0.5m (~2ft) of the surface, at which point it will refuse to go any lower. Then, if you hold the throttle stick fully down, that will command the drone to initiate an Auto-Landing during which the infrared sensors are used to settle the drone down to a soft landing.

If you disable the downward facing infrared sensors, then nothing will stop you from forcibly driving the drone into the ground (or water) when you hold the throttle down.

It has been said that the infrared sensors could be unreliable over water. But that can only mean that they might be unable to prevent the drone from descending too low into the water if, for whatever reason, your drone is losing altitude. There is no mechanism by which the infrared sensor can ever cause the drone to descend into the water.

 

[Meta4]

The same behaviour repeated. I considered, that the optical component of the vision positioning system was responsible for the erratic, spontaneous behaviour.

If you want to find out what actually happened, the first thing to do is to look into the recorded flight data.
Until then, you are just guessing.
There are a couple of options ...

1. 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 on the flight data.
Come back and post a link to the report it provides and someone might be able to analyse it and give you an understanding of the cause of the incident.
or
2. Just post the .txt file here
or
3. If you use Airdata, you can view the flight data on Airdata and post a link for the Airdata report


If you are using one of the controllers with an integrayed screen, the txt files are to be found here:

Android\data\dji.go.v5\files\FlightRecord