My ongoing saga, kind of wild. P4P disconnect mid-flight, crash.

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I find it very interesting reading about everyone's crash specifics so I'm posting mine in case anyone is like me. This is really part 2 of an ongoing saga, part 1 of which you may have seen not that long ago title "P4P lost today, I'm unclear what happened, need diagnostic help". That was close to a couple weeks ago. That day I was flying a DroneDeploy mapping mission. All of a sudden the screen went black, aircraft disconnected appeared, and I could not regain connection to the drone using either DroneDeploy or DJI Go 4. I had no idea if the drone crashed or kept flying and flew away. I searched and searched, never did find the drone. All signs pointed to a power loss, like maybe a poorly seated battery that popped out, or some hardware disconnection. The place I figured it crashed, if it did, was unreachable; too overgrown and thick. I did not know there were still logs available even when the drone is gone, so never looked to see what logs could tell me. 2 days later, I got a call from one of the crew at the job site saying they found my drone. Huh? It was about 1/8 of a mile from the site where it disconnected, completely intact, nothing visibly wrong, just sitting along a fence line. Looking at the memory card showed that it kept flying and collecting images. I guess it landed when the battery emptied. Sure didn't think that was possible, thought it would maybe just hover with no inputs from flight controller apps, or maybe land. Weird. I flew the bird for quite a while to test it, all seemed well, so I put it back in service.

Oct. 31, yesterday, same drone. This time flying manually, snapping pics of the same construction site. History seemingly repeated itself. All of a sudden the screen went black, aircraft disconnect warning appeared. Nothing I could do would let me re-connect. Now I'm thinking bad drone or bad battery. A difference this time is that I happened to make note of the radar indicator at the bottom left with the triangle that represents the drone's position. I could have sworn that I had seen the triangle going crazy out of the corner of my eye, like it was tumbling and falling, or spinning or something. In a split second that was done, but I sure felt like the drone crashed this time, unlike last time when I could not tell for sure. I spent a couple hours yesterday and a couple today searching for the drone, but it's a BIG area almost completely overgrown and unreachable. Definitely needle in a haystack stuff, and I never found it. Then tonight I discovered that I could get logs out of the controller. I grabbed the flight record txt file and uploaded it into Phantom Helper, and what an eye opener. I did not understand most of what it was telling me and still don't, but what I did discover is they have a map with the flight route overlaid on it, with notations for different warnings and such. And you can put the little drone indicator in motion with the scrubber knob and you can move the drone through its flight. Well low and behold, the flight shows exactly where the drone went down! And sliding the scrubber proves me right, the drone icon goes haywire just before crash. Also visible is a little false horizon that actually represents the attitude of the drone. As you move the scrubber the false horizon moves too corresponding to drone movement. THAT SUCKER STOOD UP ON END, meaning it rolled sharply left then sharply right. But why? I then on a whim uploaded the txt file to Airdata, and got a little more IMPORTANT info: First, I was able to get the GPS coordinates of where the drone is. Second, here's the first warning that gets notated on the flight path in Airdata: "Detected side shock / possible collision, aircraft is rolling sharply to the left". Whoa!! So...bird strike? I was at 225 feet, WELL above the tree line. This likely isn't the fault of the drone or the battery according to what I'm learning. If you care to look at the Phantomhelp log, here's a link: DJI Flight Log Viewer - PhantomHelp.com. I learned of the drone's position after dark tonight so have to wait until tomorrow to go see if I can retrieve it. Wild. I was so exasperated when I thought the same nightmare situation was unfolding twice. It's interesting to see that it's a new set of circumstances.
 

Meta4

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If you care to look at the Phantomhelp log, here's a link: DJI Flight Log Viewer - PhantomHelp.com.
Your flight went normally until 15:39.9 when the Phantom started to roll to the left and went upside down, pitched forward and spinning anti-clockwise and losing height.
The pitch, roll and yaw data suggest that the drone lost either a prop or a motor (probably the front left) and tumbled to earth.

It tumbled down from 225 feet higher than the launch point, all the way down to the trees.
The data doesn't show whether it came to rest in a tree or reached the ground.
But is should be close to 33.92694 -80.95005, or perhaps a short didtance northwest of there.
 

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So sorry for your loss. Hope you had insurance or DJI refresh.
 
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Your flight went normally until 15:39.9 when the Phantom started to roll to the left and went upside down, pitched forward and spinning anti-clockwise and losing height.
The pitch, roll and yaw data suggest that the drone lost either a prop or a motor (probably the front left) and tumbled to earth.

It tumbled down from 225 feet higher than the launch point, all the way down to the trees.
The data doesn't show whether it came to rest in a tree or reached the ground.
But is should be close to 33.92694 -80.95005, or perhaps a short didtance northwest of there.
Thanks Meta4, as always you are a big help and it’s nice to have your knowledge to rely on. I have a couple of follow-up questions.

Number one: is it possible the drone suffered a bird strike? I found the drone today, all props still attached and the motors we’re visually fine and they turn smoothly. I know that proves nothing, but still I wonder if it could be a bird strike.

Second, any thoughts about the screen going dark and the aircraft disconnected message? The weird thing is it happened to me twice as you’ve seen me describe. Only the first time the drone landed itself. This time you saw what I wrote above. I could not re-connect to the drone, yet the logs were still being written to as it fell to 20 feet.

And last: as I said, I recovered the drone. Are there any logs that are helpful to view on the actual drone itself? Or is everything in the controller? If there are helpful logs on the drone, can you tell me how to retrieve those? Thanks.
 
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So sorry for your loss. Hope you had insurance or DJI refresh.
Thanks gfields! I actually do have care refresh and I was able to find the wrecked drone today, so it's on the way back to DJI in exchange for a replacement. Glad I bought the insurance!
 
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Meta4

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Number one: is it possible the drone suffered a bird strike?
It's remotely possible, but looking at the data I don't think that a collision was the issue.
In the event of hitting something (or something hitting the drone), I'd expect to see a big sudden impact.
But the data shows the effects on pitch, roll and yaw started as small changes.
Also, the drone would stand a good chance of recovering if it was just knocked off balance.
I found the drone today, all props still attached and the motors we’re visually fine and they turn smoothly.
That eliminates one possibility and suggests something like an ESC failure.
You could see if all motors run normally, but that can't account for a frustrating intermittent fault
And last: as I said, I recovered the drone. Are there any logs that are helpful to view on the actual drone itself? Or is everything in the controller? If there are helpful logs on the drone, can you tell me how to retrieve those? Thanks.
As the drone did not shut down, someone who reads the .dat file from the drone might be able to find more about the incident.
Here's a thread that talks about accessing the drone's .dat file.
@sar104 might be able to help if he still monitors this forum
 
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I think after my strange P4P crash, that as part of a service interval say of 200-300 flights or a few years, you need to re seat all the plugs between the circuit boards.... or at least check the plus have their locking screws in place holding them connected.
 
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I find it very interesting reading about everyone's crash specifics so I'm posting mine in case anyone is like me. This is really part 2 of an ongoing saga, part 1 of which you may have seen not that long ago title "P4P lost today, I'm unclear what happened, need diagnostic help". That was close to a couple weeks ago. That day I was flying a DroneDeploy mapping mission. All of a sudden the screen went black, aircraft disconnected appeared, and I could not regain connection to the drone using either DroneDeploy or DJI Go 4. I had no idea if the drone crashed or kept flying and flew away. I searched and searched, never did find the drone. All signs pointed to a power loss, like maybe a poorly seated battery that popped out, or some hardware disconnection. The place I figured it crashed, if it did, was unreachable; too overgrown and thick. I did not know there were still logs available even when the drone is gone, so never looked to see what logs could tell me. 2 days later, I got a call from one of the crew at the job site saying they found my drone. Huh? It was about 1/8 of a mile from the site where it disconnected, completely intact, nothing visibly wrong, just sitting along a fence line. Looking at the memory card showed that it kept flying and collecting images. I guess it landed when the battery emptied. Sure didn't think that was possible, thought it would maybe just hover with no inputs from flight controller apps, or maybe land. Weird. I flew the bird for quite a while to test it, all seemed well, so I put it back in service.

Oct. 31, yesterday, same drone. This time flying manually, snapping pics of the same construction site. History seemingly repeated itself. All of a sudden the screen went black, aircraft disconnect warning appeared. Nothing I could do would let me re-connect. Now I'm thinking bad drone or bad battery. A difference this time is that I happened to make note of the radar indicator at the bottom left with the triangle that represents the drone's position. I could have sworn that I had seen the triangle going crazy out of the corner of my eye, like it was tumbling and falling, or spinning or something. In a split second that was done, but I sure felt like the drone crashed this time, unlike last time when I could not tell for sure. I spent a couple hours yesterday and a couple today searching for the drone, but it's a BIG area almost completely overgrown and unreachable. Definitely needle in a haystack stuff, and I never found it. Then tonight I discovered that I could get logs out of the controller. I grabbed the flight record txt file and uploaded it into Phantom Helper, and what an eye opener. I did not understand most of what it was telling me and still don't, but what I did discover is they have a map with the flight route overlaid on it, with notations for different warnings and such. And you can put the little drone indicator in motion with the scrubber knob and you can move the drone through its flight. Well low and behold, the flight shows exactly where the drone went down! And sliding the scrubber proves me right, the drone icon goes haywire just before crash. Also visible is a little false horizon that actually represents the attitude of the drone. As you move the scrubber the false horizon moves too corresponding to drone movement. THAT SUCKER STOOD UP ON END, meaning it rolled sharply left then sharply right. But why? I then on a whim uploaded the txt file to Airdata, and got a little more IMPORTANT info: First, I was able to get the GPS coordinates of where the drone is. Second, here's the first warning that gets notated on the flight path in Airdata: "Detected side shock / possible collision, aircraft is rolling sharply to the left". Whoa!! So...bird strike? I was at 225 feet, WELL above the tree line. This likely isn't the fault of the drone or the battery according to what I'm learning. If you care to look at the Phantomhelp log, here's a link: DJI Flight Log Viewer - PhantomHelp.com. I learned of the drone's position after dark tonight so have to wait until tomorrow to go see if I can retrieve it. Wild. I was so exasperated when I thought the same nightmare situation was unfolding twice. It's interesting to see that it's a new set of circumstances.
Looks like it's possible all 4 motors stopped turning.
1637170570659.png

Shortly after the P4P started tumbling the current dropped from 13A to 3A. In addition, the notEnoughForce flag became true which usually indicates that the motors are unable to deliver enough thrust.

More could be learned from the FLY177.DAT log file. Hopefully, that can be obtained from the mobile device running the Go 4 app. Take a look here
Mavic Flight Log Retrieval and Analysis Guide
section 3 to see how to retrieve it.

If that doesn't work then you'll need to get the .DAT from the P4P itself. Take a look here
How to retrieve a V3 .DAT File from the AC
to see how to do that.
 
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