Yet ANOTHER Drone Crash

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Hey guys!

So, I'm creating this post both to share a mildly entertaining story, and to glean some information that I need from the community. My questions are highlighted near the bottom. So let's get started...

So I just got back from Mexico this week. I did a lot of flying, and captured a lot of great video. Everything was going great until the day before I left.

My dad, my uncle, and I went to go film about an hour before sunset. Upon arriving at the site, I had trouble getting my Samsung Galaxy s6 to connect to the aircraft via the go app (the screen did not show that the aircraft was connected or the video feed). However, after fiddling around with the micro-USB cable (I had to hold the cable up against the bottom of my s6 because it was loose), I was eventually able to take off.

The flight was going great until about 13 or 14 minutes in. All of a sudden, when the battery level hit 30%, the aircraft started landing, and I could not cancel it. Why, I have no idea, since I would have easily made it back with that much battery remaining.

So I decided to just hit RTH and wait for the aircraft to arrive. However, even while executing the RTH, the aircraft kept descending! If I would have done nothing, the aircraft would have hit the side of the mountain before it ever got back to me. Therefore, I cancelled RTH and tried to navigate back manually.

Unfortunately, I had to keep fighting the AC's auto-landing while trying to come back home. By this time, I had lost a lot of battery power and I was still more than a half-mile out. With about 4% battery remaining, I lost all contact with the AC.

After waiting a few minutes to see if by some miracle the AC would magically come home, I realized that the AC had probably crashed, since I did not believe it had the sufficient battery power reach the ground below it (it descends really slowly). So, I raced to a small town near where I was to upload the flight log on my s6 to healthydrones.com

By this time, it was getting dark, and finding the drone in the dark would be close to impossible. Upon uploading the flight log, I retrieved the last known coordinates, got back in the car, and raced to the scene ( the AC's last known location was only 9 mins away from town). I felt pretty confident that's where the AC would be, since it was auto-descending. After arriving at the road next to the exact location, my uncle and I hopped out of the car and jumped the rock fence to the location. Sure enough, there it was, upside down and covered in weeds. Here's a picture:

https://i.imgsafe.org/874d9b63f4.jpg

I was so happy to find it. It was all there, and the props were not cracked. I thought I had gotten off scott-free.

I was almost right. After cleaning the AC, it looked almost the same as when I took off. Everything works as before. However, parts of the top shell are now cracked. Now the left-back arm seems to be bent because when I attach the prop to it and spin it, the prop hits the top shell of the AC. Here are some pictures:

https://i.imgsafe.org/875e6178e7.jpg

https://i.imgsafe.org/875e861fdf.jpg

https://i.imgsafe.org/875ed6745f.jpg

https://i.imgsafe.org/875eae37c1.jpg

And this one shows where the prop hits the top shell:

https://i.imgsafe.org/875ed8f46e.jpg

So my questions are:

1) Should I try to have DJI repair my AC at no cost since I don't believe it should have started auto-descending at 30 percent? Or was this pilot error?

2) How can I repair the AC myself? Will replacing the top shell allow the left back arm prop to spin freely again? If so, is replacing it easy or difficult?

3) Are there any good places you would recommend to fix my AC?

And finally...

4) How would I find out exactly how far my AC fell? I'm just curious. According to Healthydrones, the last known altitude of my AC was 204 feet, but my AC seems to be in too good condition to have fallen from that height.


THANKS!
 
When was it purchased? If it is still under warranty, trying to fix it yourself voids it, while having it professionally repaired still keeps it under warranty even if it isn't repaired through the warranty.

I agree with you though, I feel if your critical battery level was not at 30% it should have allowed you to control it.
 
You can try but I would point out that you have problem with USB connector on your GS6 so GO app might lost connection to your RC at some points.

Sent from my D6616 using Tapatalk
 
4) How would I find out exactly how far my AC fell? I'm just curious. According to Healthydrones, the last known altitude of my AC was 204 feet, but my AC seems to be in too good condition to have fallen from that height.
HD only gives you a brief summary with none of the details necessary to properly investigate most incidents.
Go to https://www.phantomhelp.com/LogViewer/Upload/
Follow the instructions to upload your flight record.
Post a link here and you'll get some help with analysis.
 
Should I try to have DJI repair my AC at no cost since I don't believe it should have started auto-descending at 30 percent? Or was this pilot error?
When the battery hits the critical low level, it'll start auto landing. Without reviewing your flight log, it wouldn't be possible to know if your Phantom performed as expected. Please upload your TXT flight log as Meta4 suggested above.

How can I repair the AC myself? Will replacing the top shell allow the left back arm prop to spin freely again? If so, is replacing it easy or difficult?
Your shell definitely needs to be replaced since you have cracks around the motor mounting area on at least one of the arms. It's a tedious job, but you should be able to do it with some patience. Check out this video for an example of what is involved.

Are there any good places you would recommend to fix my AC?
You can find some repair shops here.

How would I find out exactly how far my AC fell? I'm just curious. According to Healthydrones, the last known altitude of my AC was 204 feet, but my AC seems to be in too good condition to have fallen from that height.
If your aircraft did not disconnect from the remote controller, then you should be able to see everything in the TXT flight log (which is what you uploaded to HD). If it did disconnect from the remote controller, then you'll need to review the DAT flight log. You can find instructions for retrieving the DAT flight log here.
 
I have the DAT file as well, but how do I post it for you all to see?
You can attach the DAT file here. If it's too large, you'll need to upload it to a site like Dropbox.com and post a download link back here. The DAT file can be viewed with DatCon.
 
Here's my 1 cent...

From what I can see, the log shows the AC in RTH well before it went into Auto-land. Did you put it in RTH? Or is there some sort of smart RTH that initiated automatically? So it burned voltage climbing all the way from 500 ft to 1000 ft, which was your apparent RTH ceiling. Then, the AC realized you didn't have the battery to make it home (coming down from 1000 ft burns a lot of battery) so it went into auto-land.
 
At 12m 59s, your flight log shows you initiated RTH. At that point, your Phantom started returning back. Instead of coming back to the home point though, it seemed to have been flying parallel to the home point location.

Flight.png


At 13m 47s, your flight log shows your Phantom started landing due to a critically low battery. This probably occurred since the battery was at 3.5V and your Phantom was still 982 feet in the air. It must have calculated that it only had enough battery to make it to the ground safely at that point.

It's not clear as to what happened at the end of your flight. Either the downlink disconnected and DJI GO stopped writing to the TXT flight log or your battery shut off and your Phantom dropped from the sky. The DAT flight log will contain those missing details. I'm assuming it fell at some point since your found it upside down.
 
I did a little more digging and found some more information. The colored boxes in the screenshot below are showing the following:

Purple box: OP initiated RTH and the Phantom started returning home. The RTH altitude was set to 1,640 feet (500 meters), so the Phantom started climbing to that altitude.

Red box: The battery reached the critically low level as the Phantom was trying to ascend to the RTH altitude. At that point, it cancelled the RTH and started auto landing.

Blue box: This is where the Phantom landed (or crashed). The OP manually piloted the Phantom to that location. The flight path looks erratic since the OP was fighting the auto landing.

Flight2.png
 
I do not think DJI is going to fix your AC under warranty based on the flight log. I want to say "yes" you can invoke the warranty to try to get it repaired but as you know they (DJI) are going to analyze your flight logs.

Where I think you are going to find resistance from DJI is exactly At 12m 59s of the log, it shows RTH was initiated.

Based on the pictures you have provided, the repair of your AC is not going to be cost prohibited, whether you perform the repairs yourself or you send it in to a shop. If you are mechanically inclined you can save money on the labor.
 
I do not think DJI is going to fix your AC under warranty based on the flight log.
Right -- there is no chance this will be covered under warranty unless the OP has DJI Care.
 
I am sorry about your crash, it can happen to any of us at any time.
 
Right -- there is no chance this will be covered under warranty unless the OP has DJI Care.

Even with DJI care the OP has to pay for the shell. The shell is excluded from the program, at least It was when I bought DJI care back in July this year.


Sent from my iPhone using PhantomPilots
 
Last edited:
Purple box: OP initiated RTH and the Phantom started returning home. The RTH altitude was set to 1,640 feet (500 meters), so the Phantom started climbing to that altitude.
There's a real problem setting RTH to 500 metres.
If you are flying at 100 feet (30 metres) and initiate RTH, the Phantom is going to spend a battery-sapping 1:26 getting to 500 metres and will need another 2:46 coming down.
That's a requirement for an extra 4 minutes and 12 seconds plus the extra drain on the battery from the long climb.
Not something you want to impose on a phantom when you are already in a low battery situation, particularly in this situation where even a bare minimum RTH height would have been completely safe.

Rather than setting RTH so high, it is much better to consider how high your Phantom needs to be to clear any objects that could be between Home and where you are flying.
 
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I think this is the correct DAT file:

filehosting.org | Download | FLY085.DAT

I'm particularly interested in what happened from 5% battery to 0% (this info is not in the txt because the downlink was lost), specifically what height the AC was at when the battery ran out and it crashed.
 
I think this is the correct DAT file:

filehosting.org | Download | FLY085.DAT

I'm particularly interested in what happened from 5% battery to 0% (this info is not in the txt because the downlink was lost), specifically what height the AC was at when the battery ran out and it crashed.
I'd be glad to take a look at your .DAT. But, could you please use a different method to provide a link? The method you're using requires that I provide my email address and I'm reluctant to do that. Most pilots use Dropbox or Google drive.
 

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