RTH Changed Automatically

[JohnTodd]

Good afternoon, I had only been flying my mini 4k for a few weeks. Just around my yard and not too far until I learned to control and trust the drone. One day I was out flying and decided to use the RTH feature (even though the drone was only a short distance for my location). The drone went up to 100 m and left the area above the pine trees. I was waiting for it to return but unfortunately it did not. Due to my lack of experience I was unable to get to drone back and It landed in a swamp 1500 feet away when the battery went low. Looking at the flight log the home point was changed at about the one minute mark. I did not do this as I did not know how. So, drone lost DJI says pilot error and after many emails and phone calls with them I've come to the conclusion that they can't or won't shed and light on this situation. Ive reloaced the drone but would like to find out what really happened. Mayby somone here can help.
Thanks,
John

DJI Flight Log Viewer - PhantomHelp.com

 

[mavic3usa]

I can't read logs, the other experts on this forum are here to help. But, sounds to me like you took off *before* the homepoint was established using GPS and when it finally triggered later on, you were over a swamp and that's where your homepoint was ultimately established. I dunno, just a guess. Stay on the ground and wait for your homepoint to be established before you takeoff to go flying. sorry you lost your drone.

 

[hansenn]

very strange and definitely not a pilot error.

here is someone with also a fly-away and the same error code. Maybe you can contact this person about how it turned out?

 

[hansenn]

I wonder if updating your homepoint would have helped during the fly-away?

 

[Meta4]

So, drone lost DJI says pilot error and after many emails and phone calls with them I've come to the conclusion that they can't or won't shed and light on this situation.

DJI's analysis is correct but unfortunately DJI aren't very good at explaining things
The flight data shows a sad tale of you fumbling around, changing the homepoint without being aware you had.
There were a number of things you could have done to have saved your drone and had an uneventful flight.

Your drone will automatically record a home point when it gets good GPS location data.
Very early in a flight, when GPS reception is being refined, it's common to see the homepoint update automatically as yours did at 1.8 seconds.
This resulted in an preliminary approximate HP being replaced by an accurate HP.
The preliminary HP was 20 ft from the actual homepoint.

Six seconds into your flight, there is another home point change.
But this shows a different message in the data: Home Point updated!0 (Code: 123200).
This is not an automatic update.
It's a manual change to the homepoint which was done through the app.
In this case there was no change as the new HP was the same as the previous HP.

At 1:0.8 there is another manual change to the homepoint which resulted in setting a new homepoint 1550 ft north of where you were flying.

This should have been obvious on screen with the distance indicating the drone was now 1550 feet from the new home point.

27 seconds later, with the drone only about 30 feet away, you initiated RTH and were surprised to see the drone climb to RTH height and fly 1585 ft towards the homepoint which had been reset.
You could have cancelled the RTH and manually flown the drone back at any time, but didn't.
You could have corrected the new homepoint you had set, but didn't.

 

[hansenn]

DJI's analysis is correct but unfortunately DJI aren't very good at explaining things
The flight data shows a sad tale of you fumbling around, changing the homepoint without being aware you had.
There were a number of things you could have done to have saved your drone and had an uneventful flight.

Your drone will automatically record a home point when it gets good GPS location data.
Very early in a flight, when GPS reception is being refined, it's common to see the homepoint update automatically as yours did at 1.8 seconds.
This resulted in an preliminary approximate HP being replaced by an accurate HP.
The preliminary HP was 20 ft from the actual homepoint.

Six seconds into your flight, there is another home point change.
But this shows a different message in the data: Home Point updated!0 (Code: 123200).
This is not an automatic update.
It's a manual change to the homepoint which was done through the app.
In this case there was no change as the new HP was the same as the previous HP.

At 1:0.8 there is another manual change to the homepoint which resulted in setting a new homepoint 1550 ft north of where you were flying.

This should have been obvious on screen with the distance indicating the drone was now 1550 feet from the new home point.

27 seconds later, with the drone only about 30 feet away, you initiated RTH and were surprised to see the drone climb to RTH height and fly 1585 ft towards the homepoint which had been reset.
You could have cancelled the RTH and manually flown the drone back at any time, but didn't.
You could have corrected the new homepoint you had set, but didn't.

I did not know that you can set a different homepoint other than your current location, and I wonder if this is very easy to accomplish by (perhaps accidentally) just pressing a few buttons.

 

[TonyPHX]

I did not know that you can set a different homepoint other than your current location, and I wonder if this is very easy to accomplish by (perhaps accidentally) just pressing a few buttons.

It is documented in the user guide. Having used this a few times purposefully, I have a hard time imagining how it could be done accidentally. You would really have to be struggling with the app to have this happen.

 

[Mrktn]

You have to go into the remotes control and safety menus or DJI Fly app to change the homepoint so it’s quite difficult to do accidentally, unless the operating language was set incorrectly.

 

[JohnTodd]

very strange and definitely not a pilot error.

here is someone with also a fly-away and the same error code. Maybe you can contact this person about how it turned out?

Thanks, There has been no answer there yet. I'll watch.

 

[JohnTodd]

It is documented in the user guide. Having used this a few times purposefully, I have a hard time imagining how it could be done accidentally. You would really have to be struggling with the app to have this happen.

I can assure you that I did not change the RTH position using the safety menu as outlined in the manual.