What would happen if a drone gets disconnected from a controller, tries to RTH but its RTH altitude is set too low and on its RTH run passes over a river and into the path of trees on a hill .Collision avoidance is set to brake, would it hover until low battery forced landing into the trees or would it reverse back from trees and land in river looking for a suitable place to land?
OP error query
- Thread starter Mazdaman323lx
- Start date
Faster
Well-Known Member
If the drone has reached its RTH altitud it will hover in place until battery drains and then will land. That's why is SUPER IMPORTANT to set a proper RTH altitud.
I know , but the question is will it land into trees even if the downward sensors detect that the area is unsuitable?
Faster
Well-Known Member
It will descend to 0.5m AGL and wait, if it can't descend due to OA I really don't know what will do. Remember it's running out of battery, at the end it will land anyways, anywhere.
EpicFlight
Well-Known Member
When battery reaches critical, it will descend straight down, and land or some variation of crash, depending on what's below.
However, when encountering the obstacle if set to fly around or over, it will try to do that, and do so successfully most of the time.
However, when encountering the obstacle if set to fly around or over, it will try to do that, and do so successfully most of the time.
It was set to brake , I forgot I had 20m RTH set , school boy error I know .The Trees come right down to and slightly overhang the river .If it stopped at trees hovered and descended into them there's a chance its recoverable. It if reversed back looking for a better landing spot it would be over water . At 20m - 60 feet I'm hoping it went far enough into trees which are on a steep river side hill that it went onto dry land. Can't access area till tomorrow. As it lost connection with controller I have no exact last position reference. I presume it always flies a direct line on its RTH ?
EpicFlight
Well-Known Member
Which model?
Some will retrace their path on losing signal for a time, and only go to RTH if they don't regain signal.
I was going to ask that very question Meta4, don’t some models disable collision avoidance on RTH?
Regards
Not that I'm aware of.
Those models that use DJI Go 4 allow the user to disable obstacle avoidance in RTH, but the default option is for it to be enabled.
No DJI drone descends to the RTH height to RTH, so something else must have been going on.
Here's what the manual says for the AIr 2
Failsafe RTH
If the Home Point was successfully recorded and the compass is functioning normally, Failsafe RTH automatically activates after the remote controller signal is lost for more than 11 seconds.
The aircraft will fly backwards for 50 m on its original flight route, and then enter Straight Line RTH.
After flying for 50 m:
1. If the aircraft is less than 20 m from the Home Point, it flies back to the Home Point at the current altitude.
2. If the aircraft is further than 20 m from the Home Point and the current altitude is higher than the preset RTH altitude, it flies back to the Home Point at the current altitude.
3. If the aircraft is further than 20 m from the Home Point and the current altitude is lower than the preset RTH altitude, it ascends to the preset RTH altitude and then flies back to the Home Point.
Faster
Well-Known Member
Posting your logs will help to know better even though they could be incomplete due to disconnection from the drone.
Go here --> DJI Flight Log Viewer | Phantom Help
Scroll down to see where to find the logs stored in the mobile device you flew with.
Once retrieved & uploaded to above site they provide you with a link. Post that link here and let the masters analyzed what happened .
Go here --> DJI Flight Log Viewer | Phantom Help
Scroll down to see where to find the logs stored in the mobile device you flew with.
Once retrieved & uploaded to above site they provide you with a link. Post that link here and let the masters analyzed what happened .
I went to my DJI\dji.go.v4\FlightRecord , but every thing in it is dated from 2020 . Its a dedicated phone i use only for droning and so doesn't have a sim card . It last had a sim card 2020 . It connects to home wifi regularly . This screws my fly away care refresh or am i missing something ?
Last edited:
The sim card is irrelevant.
But what might make a difference is that the air 2 doesn't use DJI Go 4
Your files should be in:
DJI\dji.go.v5\FlightRecord (for older versions of DJI Fly)
or Android\data\dji.go.v5\files\FlightRecord
Since the drone lost signal, data from the interesting part of the flight won't be recorded.
But perhaps there will be a few clues that help.
Spent a couple of hours fighting my way thru the forested hill which I think prevented the RTH , no joy. Without a last known position the search area is too big. Hopefully if I can retrieve the right flight log and some genius can give me the last known position before connection was lost and Calculate the RTH flight path back to the home point overlaid on Google maps? This would narrow down the search area greatly. That said it could be 60 feet up in a tree . I could also hopefully claim a flyaway care refresh. I'll post the flight log later tonight soon as I get back. Thanks for the help to date
Not to pressure on anyone but my care refresh expires on the 17th . Anything in the flight log to win or lose a flyaway claim ?
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