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Can someone explain as to what happened?
580 12 2019-11-29
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Thermographer
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I see the data indicates that i was telling it to increase in altitude.  but i could swear i was tring to get it decrease in altitude.  still not sure why it climbed to 800 feet, wind gust maybe?

all i can say is that around the fifteen minute mark i had the left stick down, the data doesnt indicate that.

enough rambling waiting for the experts...

Thanks for your help.



https://www.phantomhelp.com/LogViewer/OT2TLMAEJ4VIJCU551JX
2019-11-29
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Mark The Droner
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The log shows your altitude increased from around 400 ft to around 800ft from 11 mins to 15 mins.  Yet the log shows your sticks at mid point.  How can this be?

If you look at the 10 min area, you are repeatedly losing and regaining your downlink which indicates a weak incoming signal at the very least.  Then you moved further away. Often in the logs, when the downlink signal becomes weak, the early columns of data will be updated but the later columns in the same row of data will be redundant - which is to say they will just repeat what was in the previous row.   In other words, that data in the latter columns, which would log stick movement, would be incorrect relative to the time.  This can be verified by looking at a csv of the whole data log.

From the flight path, while the FPV screen was lagging or locked up, it looks as if the pilot deliberately increased altitude in order to get a better incoming signal.  At the same time, the AC was moving further away.  

Re the latter part of the flight such as around the 15 min mark, I don't have a P3S but I know it's a lot like the P2V series.  In a P2V, if the AC is in RTH, the stick controls are disabled until you either cancel RTH, or the AC is over the home point.  This may be why the log shows your sticks are centered.  
2019-11-29
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Thermographer
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Mark The Droner Posted at 11-29 06:44
The log shows your altitude increased from around 400 ft to around 800ft from 11 mins to 15 mins.  Yet the log shows your sticks at mid point.  How can this be?

If you look at the 10 min area, you are repeatedly losing and regaining your downlink which indicates a weak incoming signal at the very least.  Then you moved further away. Often in the logs, when the downlink signal becomes weak, the early columns of data will be updated but the later columns in the same row of data will be redundant - which is to say they will just repeat what was in the previous row.   In other words, that data in the latter columns, which would log stick movement, would be incorrect relative to the time.  This can be verified by looking at a csv of the whole data log.

Yeah, I tried to cancel RTH several times with no luck
2019-11-29
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Mark The Droner
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Thermographer Posted at 11-29 06:59
Yeah, I tried to cancel RTH several times with no luck

What method did you use to cancel RTH?  
2019-11-29
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Labroides
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It would be so much easier to tell what happened if you had been using DJI Go.   

Litchi flight logs are horrible to analyse, particularly when looking for something small like this.

2019-11-29
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Thermographer
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Mark The Droner Posted at 11-29 12:07
What method did you use to cancel RTH?

The button in the app.
2019-11-30
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Thermographer
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Labroides Posted at 11-29 20:22
It would be so much easier to tell what happened if you had been using DJI Go.   

Litchi flight logs are horrible to analyse, particularly when looking for something small like this.

Yeah, I was going to use "go" but the app froze while trying to give DJI permission to get my location and so forth.
2019-11-30
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Thermographer
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Mark The Droner Posted at 11-29 06:44
The log shows your altitude increased from around 400 ft to around 800ft from 11 mins to 15 mins.  Yet the log shows your sticks at mid point.  How can this be?

If you look at the 10 min area, you are repeatedly losing and regaining your downlink which indicates a weak incoming signal at the very least.  Then you moved further away. Often in the logs, when the downlink signal becomes weak, the early columns of data will be updated but the later columns in the same row of data will be redundant - which is to say they will just repeat what was in the previous row.   In other words, that data in the latter columns, which would log stick movement, would be incorrect relative to the time.  This can be verified by looking at a csv of the whole data log.

Trying to get permission from the land owner to search for it, need to be careful deer hunting season.  where would you think the crash site would be?  Traveling 45.5mph @ 800 feet at disconnect.
2019-11-30
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Thermographer
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What is the difference in the yellow and green flight paths in the log viewer?
2019-11-30
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Mark The Droner
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That was your mistake.  If you're in RTH, the 2.4 ghz signal could be weak, intermittent or non existent.  The better RTH cancel is to toggle the S1 switch because that's the 5.8 ghz control signal - it will be the stronger signal.  

Good luck finding your drone.  
2019-11-30
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Mark The Droner
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Thermographer Posted at 11-30 05:40
Trying to get permission from the land owner to search for it, need to be careful deer hunting season.  where would you think the crash site would be?  Traveling 45.5mph @ 800 feet at disconnect.

That's a tough one.  There are a lot of unusual things going on.  You'd have to take into account the 800 feet altitude from launch, and the drone moving at 45 mph away from you, and also changing levels of terrain.  Not a good combination.  In addition, the log seems to show you were deliberately driving the drone away from you at top speed with the wind pushing it even faster, probably because your FPV screen was frozen.  The log shows it was in auto land because it had been in RTH and it had reached its position over homepoint and began its descent, but your controller then drove it away.  The log also is showing you are full up with the up throttle on the controller.  That explains why it's not descending while in autoland.  But you're driving it away.  Then you lost the 2.4 ghz signal.  So that's an unknown variable.  When did you stop driving it away from you and stop fighting the autoland?  After you completely lost the 2.4 ghz signal?  How long after?  One minute?  Two minutes?  Three minutes?  Knowing the answer to that question is going to be a huge help in trying to figure out where it might be.  The AC is moving three quarters of a mile every 60 secs over dense woods.  Finding it in all those woods seems like pretty much an impossible task to me.  it would be hard to find even if you knew exactly where it was.  Fortunately you have at least two more drones, right?  Probably the best estimator of a crash landing site location is msinger.  You might PM him.  

If it makes you feel any better, I've made a similar mistake - twice- on two different occasions.  My controller is modded to stay in right-stick full-forward position, so two different times, I had forgotten to take the right stick out of full forward, and so it was in RTH and arrived over the home point, the drone stopped momentarily to begin descent, then took off like a jet in the same direction it was pointing, which was behind me.  By the time I realized my mistake and realized it took off on me, it was 1000 feet behind me and still descending.  I tried to RTH it again but battery was too low.  Ended up landing in an empty field a quarter mile away.  You'd think I'd learn my lesson but then I did it again a year later.  It was easy to find both times because I have a GPS tracker on all my drones.  Just missed a tree in the open field the first time.  Both times, it was sitting in the tall grass of the field safe and sound and waiting for me.

Good luck
2019-11-30
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Mark The Droner
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Thermographer Posted at 11-30 05:55
What is the difference in the yellow and green flight paths in the log viewer?

The yellow is telling you there is a problem of some sort.  In this case, it's warning you that your battery cells are getting low.  You can see the warning in the log.  
2019-11-30
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Pleomax
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Thermographer Posted at 11-30 05:55
What is the difference in the yellow and green flight paths in the log viewer?

Mark is right regarding coloured flight paths.

There is also a DJI flight record recorded.

Look in  DJIGo folder/com.flylitchi.litchi/FlightRecord for the flight date.

Upload this, it may help in recovery.

Good luck.
2019-11-30
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