Hi,

DJI Mini 2 with latest firmware installed. Flying in normal mode.  I launched from the top of a waterfall (set at 0m altitude), then flew out over the falls. Descended to about -6m from my reference height. Initiating full down left stick to descend the waterfall started landing mode, which I had to cancel. This occured repeatedly.

After cancelling the landing initiation, with the aircraft at -7m, it slowly started climbing. This aircraft response for flights below 0m was confirmed multiple times.

I was uncomfortable flying the landing initiation as below the aircraft was a pool of water from waterfall, and I wanted the downward vision system to identify this.

Is the only option to fly such a profile to apply left stick down input, but not at full deflection that would initiate landing ?  

I recommend DJI provide the ability in DJI Fly to allow flight below 0m reference, and adjust the flight software to remove the slow ascent of the aircraft when flying below 0m.  

Thanks
Ian

Stop slowing the descent when at zero? That could make for some very hard landings.

Most of us know these drones are not great at determining "visual sensor" altitude above water,

GaryDoug Posted at 4-18 18:28
Stop slowing the descent when at zero? That could make for some very hard landings.

Most of us know these drones are not great at determining "visual sensor" altitude above water,

Thanks GaryDoug. My point is in regards to flights below 0m.

Agree that coming back to land from a positive altitude to 0m should have decent slowed and DVS enabled.

Unsure why the aircraft has to ascend when it is comfortably flying -8m below launch point and also horizontally offset from launch point (ie: the aircraft should know that ground below it is clear, else DVS would have detected it). It's a real pain.

At zero feet, below zero feet. The sensing system is not that exact in many cases. It is not a perfect system, especially over water. Just a few days ago, I had to struggle a little bit to keep my MA2 from landing in the water next to my boat ;-)

Hi,

Best to get advice / help is to upload your flightlog, using this > https://www.phantomhelp.com/LogViewer/Upload/

(never mind as it looks empty...)

Your landing is a forcelanding, this is initiate if some conditions are met,
1) VPS height measures (or false measuring) a height of 0.5 meter
AND
2) 100% stick down for a while

Flying close to a waterfall mayby made your sensor wet, resulting in a false reading. (and a forcelanding....)

DJI software is OKE, yo can fly perfectly < 0 meter if the VPS height sensor is measuring correct.

cheers
JJB

I fly from hills all the time, so I'm often flying below the home point and have not experienced this. The aircraft will descend at full rate (stick 100% down) without initiating landing. I've also never had it ascend automatically.
Sounds like water vapour in the air may have confused the VPS?

Have you tried this anywhere other than near the waterfall?

JJB* Posted at 4-18 23:08
Hi,

Best to get advice / help is to upload your flightlog, using this > https://www.phantomhelp.com/LogViewer/Upload/

Thanks JJB.

I'm a new Drone pilot, but also an Aeronautical Engineer and private fixed wing pilot, so I respect the learning curve. Appreciate all the advice. Will upload the flight log. I was about 10 m laterally from the water fall, and it's a fairly low flow falls, so I don't think the sensor was activating.

Thanks for the guidance and tips on getting the full experience out of this tech.

Cheers

delf67 Posted at 4-19 00:50
I fly from hills all the time, so I'm often flying below the home point and have not experienced this. The aircraft will descend at full rate (stick 100% down) without initiating landing. I've also never had it ascend automatically.
Sounds like water vapour in the air may have confused the VPS?

Thanks delf67,

.No, this was my first flight below 0m. I have a few lookouts near me that are perfect flying locations to get a 30m descent or so. I'll test it and report back.

Cheers

Ian.taylor4 Posted at 4-19 01:28
Thanks JJB.

I'm a new Drone pilot, but also an Aeronautical Engineer and private fixed wing pilot, so I respect the learning curve. Appreciate all the advice. Will upload the flight log. I was about 10 m laterally from the water fall, and it's a fairly low flow falls, so I don't think the sensor was activating.

The only reason that your drone went into a forcelanding is the fact that the VPS height sensor measure height!  value of 0.5 meter.

If you like upload your log, so i can show you what happend.

cheers
JJB