Lost P4

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Hey all - lost signal on my P4 today while the app was trying to update. It's somewhere in the hills - i hope. Please let me know how to upload my last GPS coordinates so I can find it.
 
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msinger

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Please upload your TXT flight log here and post a link back here.
 
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OK thanks. I posted what I believe is the latest log. I had 2 flights and it went AWOL on the 2nd flight. I searched on foot yesterday for an hour or so, but I could not find it. It's very hilly terrain with a power line at the top.
 
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We searched in the area where the last GPS shows it was but didnt see it. Maybe someone snatched it. Maybe we missed it. Or, can you tell from the log if it was still trying to RTH or did it land?
 
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Here's the log.
 

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  • DJIFlightRecord_2017-04-04_[16-23-24].txt
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Meta4

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We searched in the area where the last GPS shows it was but didnt see it. Maybe someone snatched it. Maybe we missed it. Or, can you tell from the log if it was still trying to RTH or did it land?
This flight record shows something I've not seen before.
You flew out in a variety of modes, trying Sport and P-GPS and then switched to beginner mode at 5:33 when 4300 feet out and at 393 ft altitude.
I'm not sure what happens when you switch to beginner mode at a distance because beginner mode wants to stay within 30 metres of home.
Anyway your Phantom then began to descend without you touching the sticks and when it came to 314 feet above home point, the record stops.
If we look at the terrain between you and the Phantom, the reason signal was lost is explained.
There is a big lump of rock halfway between you and the Phantom.
Although the Phantom is higher than the hill, the line of sight is blocked by the hill and signal is lost.
i-dKfCdWC-XL.jpg

i-wZSqPDJ-L.jpg

After this I have to guess what happened.
Presumably the Phantom continued descending until it was 30 metres above home and if it attempted to RTH, it would have bumped into the base of the hill somewhere on that yellow line where the ground is 30 m higher than launch point?.
 

ianzone

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Hey all - lost signal on my P4 today while the app was trying to update. It's somewhere in the hills - i hope. Please let me know how to upload my last GPS coordinates so I can find it.
Good luck hope you find,,,looks hard going on foot,,,:oops:you need a spare drone to look for white objects ,,,:)Goodluck again
 
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This flight record shows something I've not seen before.
You flew out in a variety of modes, trying Sport and P-GPS and then switched to beginner mode.... .

Maybe because the app tried to update during the flight?

Good luck hope you find,,,looks hard going on foot,,,:oops:you need a spare drone to look for white objects ,,,:)Goodluck again
I hope you can find it too. I see a lot of water nearby. Hopefully it didn't land there.
Pleas keep us updated and good luck!
 
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msinger

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At the end of your flight log, your Phantom was over top of the red circle in the image below. Since it was in beginner mode, it most likely continued to descend to 98 feet (the max allowed altitude in beginner mode). After it reached 98 feet, it should have started returning home on the yellow path.

01.jpg



At an altitude of 98 feet, it wouldn't have made it too far before crashing into the side of the hill. Look for it around the area circled in red below.

02.jpg
 
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Hey all - lost signal on my P4 today while the app was trying to update. It's somewhere in the hills - i hope. Please let me know how to upload my last GPS coordinates so I can find it.

Has a new update just came out?
 
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Found it!! Thanks so much msinger! I have the log from the P4, but it's 1gb - how can I upload that to share?
BTW- it was right where you said it was, I think. Need to look at the log to find out.
 

msinger

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Upload the log to dropbox.com and post a link back here.
 
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I looked at the .DAT and it's pretty much as @msinger and @Meta4 described. The end of the flight is interesting. Apparently, the P4 didn't run into the hill. Instead, after it lost connection it was descending and returning home when it decided to stop and land.

334. The P4 was already in the GoHome state and the pilot switched to Novice. For some reason the P4 had not been moving. The response to the switch to Novice was the P4 started to descend without moving.

359 Connection was lost. The P4 continued to descend without moving.

366 The P4 had descended to 87 meters and started to move towards home while continuing to descend.

397 Height 64 meters, Stopped moving towards home but continued to descend. This point is shown on graphs and overhead.

404 vps height 8.4

415 Height 41 meters. vps height 0.1. Motor speeds, gyro, accelerometers indicate the P4 had landed but the motors continued to turn. Looks kinda like the props were caught in something and the P4 was thrashing about.

454 A relatively stable state is entered where motor speeds are constant, although elevated and uneven. The right back is turning higher indicating maybe the right back prop was partially broken? The gyros and accelerometers are stable at this point.
upload_2017-4-10_7-1-55.png

upload_2017-4-10_7-2-9.png

upload_2017-4-10_7-2-23.png

upload_2017-4-10_7-2-38.png


It looks to me like the P4 landed on not level ground and the motors continued to turn in order to keep itself level.
 
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I was brought over here from MavicPilots, to read the flight log. I must say this is a fascinating read. In any event I am curious how the drone would respond if beginner mode were shut off before the signal was lost. Could the drone be controlled again or is it going to continue to force it's way back.
 

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In any event I am curious how the drone would respond if beginner mode were shut off before the signal was lost. Could the drone be controlled again or is it going to continue to force it's way back.
Yes .. the home point would have stayed in memory and the Phantom wouldn't have descended and lost signal and attempted RTH if it was switched out of beginner mode and things would have been normal.
 
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I probably left this out, but the pilot has pushed the RTH and it was going home when the Novice mode was selected. Presumably, the RTH could have been cancelled; Novice or non-Novice not being relevant. The question I have is why did the P4 stop at time 397 and land where it did?vpsHeight didn't come on until later. It wasn't over the HomePoint.
 

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The end of the flight is interesting. Apparently, the P4 didn't run into the hill. Instead, after it lost connection it was descending and returning home when it decided to stop and land.
Is it possible that the obstacle avoidance saw an obstacle, was unable to overcome it due to the beginner mode altitude restriction, and decided to auto land instead of continuing onward?
 
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Yes, when I lost control of the DJI app on my phone and was unable to recover it I hit the RTH button. I kept attempting to reconnect after ending and relaunching the app, but it wouldn't connect.
The P4 was sitting between a bush and rock when I recovered it, landing gear on the ground. 1 prop in particular has the most damage, but really just a few cuts, not broken completely. I think it probably hit the rock and/or bush while landing. Had it attempted to land 1 foot to the west it would have landed on the rock and fallen off and rolled quite aways down a steep hill - got very lucky.
 
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Is it possible that the obstacle avoidance saw an obstacle, was unable to overcome it due to the beginner mode altitude restriction, and decided to auto land instead of continuing onward?
Might be something like that. Seems that the frontSensorDistance had a value for most of the flight which is kinda odd. At 396.8733 frontSensorDistance had been at 10 but then dropped to 4. Then 0.1 secs later the descent began.
upload_2017-4-10_15-15-39.png


The current version of CsvView/DatCon doesn't have the frontSensorDistance. Contact me if you want a beta that has frontSensorDistance.
 

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