I was flying a Mavic 2 Pro from atop of a mountain and wanted to film something on a hill below me. As I decended down I got to a negative 54 feet and I got a warning that the drone wanted to land. I hit the controls to raise the drone and it went fine but I was scared to try lowering the drone again since it was about a mile away. Would the drone actually have landed? And how do I prevent this from happening again if I want to take pictures or videos that are below where I take off?

I had a very similar problem with the M2 and aside from pulling up to cancel, could find no other way to fix.

Hi,

Interesting case, please upload your flighlog using
this link > https://www.phantomhelp.com/LogViewer/Upload/

and post the uploaded link on here.

Negative height values does not trigger an autolanding, flying low abvove ground with stick down command does.  Flightlog will show what happend.

cheers
JJB

JJB* Posted at 5-7 10:10
Hi,

Interesting case, please upload your flighlog using

how do I do that?

JJB* Posted at 5-7 10:10
Hi,

Interesting case, please upload your flighlog using

I posted before I finished my question. I use the smart controller instead of a cell phone. Is the flight info on the controller or on the chip from the drone?

deputyrick Posted at 5-7 10:17
I posted before I finished my question. I use the smart controller instead of a cell phone. Is the flight info on the controller or on the chip from the drone?

flightlog is on the mobile device, so in your case it must be on the smart controller.

Its android if i am correct, folder like DJI go / flightrecords / *.*    [not sure about the true naming ]

JJB* Posted at 5-7 10:32
flightlog is on the mobile device, so in your case it must be on the smart controller.

Its android if i am correct, folder like DJI go / flightrecords / *.*    [not sure about the true naming ]

I found the folder on the smart controller, but the print out is anything but English. Its nothing but numbers, letters and symbols.

deputyrick Posted at 5-7 11:30
I found the folder on the smart controller, but the print out is anything but English. Its nothing but numbers, letters and symbols.

yes, its encrypted.

This flightlog.txt to be uploaded into this > https://www.phantomhelp.com/LogViewer/Upload/

Than after the upload, put this link on here

cheers
JJB

JJB* Posted at 5-7 11:36
yes, its encrypted.

This flightlog.txt to be uploaded into this > https://www.phantomhelp.com/LogViewer/Upload/

Here you go, hope it helps.  https://www.phantomhelp.com/LogViewer/MYS5JR1RH9MVHGLI3699/

deputyrick Posted at 5-7 12:08
Here you go, hope it helps.  https://www.phantomhelp.com/LogViewer/MYS5JR1RH9MVHGLI3699/

Hi,

Oops, few drone flyers did loose their drone this way.....(above water).

If a DJI drone flys low altitude (hover or any moving direction), about 0.5 meter above the ground AND user is applying for short moment 100% down stick ; drone will enter an autolanding mode.  Its the same as a normal landing, hover at this height and 100 down stick > autolanding.
Sometimes it happens at between 70 - 99 % down stick, try it yourself during normal landing.

The only way to stop this is to pull up, as you did.   But if you are not aware of this than....AND if VPS height is misreading height (above clouds, fog etc) or simple an error ; than also into an autolanding.

See my chart.

cheers
JJB

JJB* Posted at 5-7 12:15
Hi,

Oops, few drone flyers did loose their drone this way.....(above water).

That explains it. I was lowering to take a picture of an old cabin and I was still well above the old chimney, I'm guessing maybe 50 feet above the ground when the warning came on.  It would have been one long hike to retrieve the drone. I wish one day they'd come up with an altimeter that actually shows your true above ground level.
Thank you

I have only seen this when people fly very very high. Can you realise what was the actual flight altitude ?

deputyrick Posted at 5-7 12:40
That explains it. I was lowering to take a picture of an old cabin and I was still well above the old chimney, I'm guessing maybe 50 feet above the ground when the warning came on.  It would have been one long hike to retrieve the drone. I wish one day they'd come up with an altimeter that actually shows your true above ground level.
Thank you

That explains it. I was lowering to take a picture of an old cabin and I was still well above the old chimney, I'm guessing maybe 50 feet above the ground when the warning came on.  It would have been one long hike to retrieve the drone. I wish one day they'd come up with an altimeter that actually shows your true above ground level.
The VPS sensors do show your height above ground level - but they only have a range of 0-30 ft.


There were several times during the flight where the VPS sensors detected that your drone had an obstacle very close below it.
If you look at the Phantomhelp viewer and concentrate on the VPS Altitude column, you see this at:
3:55.6
3:59.7
4:07 - 4:10.8
4:38.9
4:48.6
Either you were in among tree branches or you have something causing false readings from your VPS sensors.
Do you have anything fitted under the sensors that might block their downward view?

It looks like the warning was at 4:23.9 when the VPS sensors data indicates an obstacle less than one foot below the drone and you held the left joystick full down.
The drone took this as a command to land,

In the spreadsheet data here, the yellow highlighting shows when VPS indicated something close below the drone and the pink shows you holding the left stick full down.

Eralp SAYGIN Posted at 5-7 14:54
I have only seen this when people fly very very high. Can you realise what was the actual flight altitude ?

This should never show when flying very high.

Labroides Posted at 5-7 15:55
That explains it. I was lowering to take a picture of an old cabin and I was still well above the old chimney, I'm guessing maybe 50 feet above the ground when the warning came on.  It would have been one long hike to retrieve the drone. I wish one day they'd come up with an altimeter that actually shows your true above ground level.
The VPS sensors do show your height above ground level - but they only have a range of 0-30 ft.

It may have been trees because I didn't have anything attached to the drone. I went back and looked at some of the pictures and video of the area and I'm guessing that the flight log is showing I got near some dead trees from a fire 8 years ago that I hadn't noticed at the time. Its pretty amazing how you can figure out everything from the log.

deputyrick Posted at 5-7 12:40
That explains it. I was lowering to take a picture of an old cabin and I was still well above the old chimney, I'm guessing maybe 50 feet above the ground when the warning came on.  It would have been one long hike to retrieve the drone. I wish one day they'd come up with an altimeter that actually shows your true above ground level.
Thank you

My pleasure, you can check the critical height....

Hover high (near yourself) and apply full throttle down and don`t change this input.
When the VPS height sensor is in range the descend will slow down and craft stops at approx 0.5 meter (while still applying 100% down stick). Shortly after this it will enter the autolanding mode.

So only at this height (0.5 mtr) and stick down will command an autolanding.

cheers
JJB

Labroides Posted at 5-7 15:56
This should never show when flying very high.

Ive had it trigger at 400ft over a smooth, ripply ocean before now.

gnirtS Posted at 5-8 21:16
Ive had it trigger at 400ft over a smooth, ripply ocean before now.

If the VPS height sensor does indicate height flying high altitudes is measures "incorrect" but can happen flying above clouds, mist, fog etc. Or just a simple a false indication.
But when this happens and you apply down stick it will enter a forcelanding mode.

Happend to a guy in SA, took ages for the craft to descend all the way down, just enough juice left in the battery. ( if only he had pushed up to cancel this mode...)

cheers
JJB

I fly over water and wet landscapes a lot (ocean, tropical swamp etc) so i see it fairly often.  I get obstacle avoidance braking a lot due to the same.
FWIW my mavic 1 seemed less susceptible than my M2. Presumably ultrasonic vs visual for VPS has an effect.

But yes as with anything else "automatic" taking over, a flick to sport mode etc will quickly get you manual.