I had a couple of odd things happen during a couple of short flights on Saturday.

First one was the aircraft trying to land at something like 20m above the ground - and the app showing it was landing.

The second was the aircraft flying backwards quite fast immediately after take off.

The first issue is even more odd because when I look at the flight 8n the flight data center in the Fly app the 'landing' warning does not flash up at the point that it did when actually flying. I need to check again, but I think you can see me use up-stick to stop it trying to land.

Once I climbed a bit I was able to descend again no problem without the aircraft trying to land.

The second was more worrying and after landing and taking off again the aircraft continued to fly backwards slowly with no control input, but after flying forwards and backwards a few times seems to settle down.

I'll upload flight logs later, but wanted to get some ideas in the meantime.

It may or may not be relevent, but the second issue was after taking off from a car park where the ground sloped up slightly - maybe 15 degrees. So the attitude of the aircraft was nose up on the ground. Could this be part of the problem as the props would already be tilted in a direction to fly backwards, or does the drone realise this and compensate?

No Original Thought Posted at 1-23 04:48
It may or may not be relevent, but the second issue was after taking off from a car park where the ground sloped up slightly - maybe 15 degrees. So the attitude of the aircraft was nose up on the ground. Could this be part of the problem as the props would already be tilted in a direction to fly backwards, or does the drone realise this and compensate?

HI,

Props are fixed to the body in rotation path, they do not tilt in any direction.
Due to differences in rotation speed drone body will change attitude.

cheers
JJB

I'll upload flight logs later, but wanted to get some ideas in the meantime.
The best "ideas" will come from analysis of the flight data rather than guesses.

"but I think you can see me use up-stick to stop it trying to land."

Yes you can stop all the landings except the empty battery landing by pushing up on the left stick.

DAFlys Posted at 1-23 06:34
"but I think you can see me use up-stick to stop it trying to land."

Yes you can stop all the landings except the empty battery landing by pushing up on the left stick.

I'm aware of that, but I mention it because at that point in the replay if the flight in the flight data center the landing warning message doesn't appear in the app.

It definitely appeared during the flight, so I wonder if the landing message normally appears in the replay - off to check with other flights in the data center right now.

No Original Thought Posted at 1-23 07:44
I'm aware of that, but I mention it because at that point in the replay if the flight in the flight data center the landing warning message doesn't appear in the app.

It definitely appeared during the flight, so I wonder if the landing message normally appears in the replay - off to check with other flights in the data center right now.

Ok, so it appears that that message doesn't appear in other flights when landing either, so that would explain the lack of message on screen during playback.

Need to find time to upload the logs... But looking at the flight where the aircraft shot backwards at speed, it looks like a GPS issue to me. Although I waited for a good lock and HP update before taking off, I did get a GPS warning in flight (about a l minute after take-off I think) but more importantly looking back at the flight path in the flight data centre, it does not match the actual path flown at all!

I suspect that occasionally, in my case 'hand tilt',  causes some initial drift but that is only a suspicion, at other times I get pure vertical lift offs, my drift tends to be forward and left, i.e. diagonal.
That said, I have noticed that where the drone is placed on a slope the lift off is performed in two stages, it first levels itself then it actually lifts off, on a steepish slope care might be needed just incase this levelling cause the high side props to strike the ground.

With regards to the flightpath not matching your recollection, does that persist through out the replay or is limited to a portion of the flight?
I ask because some of my flight tracks in Airdata have had impossible bits at the start due to the fact that I often launch with insuffuicient GPS. The Airdata track show where it is thought the drone was and then, when the drone gets sufficient GPS, the track jumps to the correct position. I rarely look at the replays on the phone so don't know if they show the same quirk.

No Original Thought Posted at 1-23 07:49
Ok, so it appears that that message doesn't appear in other flights when landing either, so that would explain the lack of message on screen during playback.

Need to find time to upload the logs... But looking at the flight where the aircraft shot backwards at speed, it looks like a GPS issue to me. Although I waited for a good lock and HP update before taking off, I did get a GPS warning in flight (about a l minute after take-off I think) but more importantly looking back at the flight path in the flight data centre, it does not match the actual path flown at all!

Need to find time to upload the logs.
It only takes 2-3 mins.
The data will show what actually ahppened.
Guessing without data is pointless.

Well, I've fallen at thw first hurdle... I've read the log locations on phantomhelp and I don't appear to have those folders on my device!

Off to search again... But I won't have a chance to connect to my computer until tomorrow so searching with an Android file browser at the moment ..

No Original Thought Posted at 1-23 13:28
Well, I've fallen at thw first hurdle... I've read the log locations on phantomhelp and I don't appear to have those folders on my device!

Off to search again... But I won't have a chance to connect to my computer until tomorrow so searching with an Android file browser at the moment ..

No joy with the Android file browser .. will have to wait until tomorrow at the earliest

No Original Thought Posted at 1-23 13:34
No joy with the Android file browser .. will have to wait until tomorrow at the earliest

You are looking in the wrong location.
To find the txt file you need to go to:
Android\data\dji.go.v5\files\FlightRecord

Note ... you start at Android\data ... not DJI\dji.go.v5

From memory a search for "DJIFli" using the in phone search function found my logs irrespective of where they were.

I upload my logs to DJI,  then use a free airdata account to access them or you can download the raw log to upload at http://phantomhelp.com/logviewer/

Labroides Posted at 1-23 15:05
You are looking in the wrong location.
To find the txt file you need to go to:
Android\data\dji.go.v5\files\FlightRecord

Thanks, I did check there first but was looking for com.dji... which is the standard format for Android package names.

Have grabbed the logs now and it looks like it was a GPS issue for the backwards flight and a VPS issue for the false landing issue.

Will post links shortly.

DAFlys Posted at 1-24 00:51
I upload my logs to DJI,  then use a free airdata account to access them or you can download the raw log to upload at http://phantomhelp.com/logviewer/

I've been meaning to set up an AirData account... Must do that.

No Original Thought Posted at 1-24 01:34
I've been meaning to set up an AirData account... Must do that.

You can put the DJI account details in to your profile and they automatically sync the logs over once a day or you can trigger it with their free hd sync app.