P3P suddenly fell from the sky

This was like reading a murder mystery, with a happy ending. Happy for you. ......But 10 weeks of anxiety and mental anguish. [emoji33][emoji35]
 
@jwmcgrath and @sar104, thank you very much for your analyses and hypotheses. They both sound like possible causes for the AC to suddenly drop. Do you think there is enough data to ask for a replacement, since it's still within the warranty period? There's no proof of a bird strike. From your feedback, there doesn't seem to be any definite proof of something external to the P3P that would cause the prop to fly off. A bird strike might be a possibility, but no definite proof.

I think, from a "warranty hopeful" perspective, you may be facing something exactly like this:

Yeah. DJI didn't send me a detailed report as to what went wrong just a (paraphrased) "oops. Our bad. Here's a fixed one." note. Took 10 weeks but at least I didn't have to pay for it.

We can try to do the best we can to analyze everything for you but in the end, they will decide whether it's covered or not.

I truly hope they cover it for you and hope they explain why!
 
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This was like reading a murder mystery, with a happy ending. Happy for you. ......But 10 weeks of anxiety and mental anguish. [emoji33][emoji35]
At least you are not going to pay for the fixing... I can wait longer than that :)
 
Nice video, nice time of day, nice lighting, great plan. It did appear that, at times during the video, I noticed evidence of birds close by in the right part of the image. Birds don't attack from bottom up. They attack from the top. The camera will not likely pick them up. When attempting to grab your drone from the top, they will do damage to the props and likely sustain injury to themselves. I have an island on my lake that is inhabited by eagles. I keep my drone away from the island and try not to have extended flights that might attack their attention.
 
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Look closely at the 2:53 mark of the video. What is the object on the right side of the screen that flashes and then is gone?
 
Look closely at the 2:53 mark of the video. What is the object on the right side of the screen that flashes and then is gone?

Appears to be the right side landing gear with something black attached.

Frame-22-04-2017-12-38-00.jpg
 
A bird was my thinking. Whatever it was it was very close but never touched the aircraft as evidenced by the continued normal flight. There were other instances of distant birds in the video.
 
I did a test some time back to see if suddenly slowing a motor (active braking) could make a prop fly off. I installed a prop as loose as possible and manually grabbed the motor bell at different speeds. I found that it was nearly impossible to make this happen. Just starting the motors would snug up a loose prop pretty well. Only at the very highest speeds, with a completely loose prop was I able to make one fly off. I also tested the effect of losing one motor phase as would happen with a disconnected wire or ESC glitch. In this case the prop would fly off instantly and consistently even if it had been installed pretty snug. I think this is more likely the cause of many of the prop loss crashes that were blamed on props not being installed tight enough.
At times in this video, the prop looks like it is moving slowly but it is just turning at a rate near the camera's frame rate. At the end of the video, you can see what happens if you disconnect a wire and lose one motor phase. Obviously, this was not a P3 but the physics should be the same.
Great video brah... And should put to rest this "prop fly off" debate.
 
I had a similar failure 2 or 3 weeks back when flying my P3S above my home it was with a genuine DJI battery that I had bought off Ebay, Seller insists is is Genuine, at about 70m high after 3 or 4 minutes I noticed a Battery damaged warning where the remaining battery shows on the app, so tried to descend ASAP, at around 40m I saw it lose power and drop like a rock, hit the Garage roof, bounce off onto the ground, I was sure it was going to be completely destroyed, But was wrong, The quick release prop guards had all come off, and 3 of the 4 props damaged, Landing gear legs bent but still held, minor hairline crack on the body, but fairly substantial damage to the Camera and Gimbel.
After replacing the props I decided to test it , and it actually still flew, although the Live Feed to my phone doesn't work, so in a sense you are flying blindly hoping the camera is seeing what you want, still takes photos and video, but the video isn't 100% stable like before the crash, the Gimbel still rotates and moves up and down, and when I tested it with the battery from Ebay it worked faultlessly, So I am at a complete loss why it lost power and dropped.
I have sent it back to my seller, but don't really expect it to be covered as they are most likely to say it was operator error as I have nothing to really back up my story.
 

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What is the dark object that appears in the upper right-hand corner of the camera view at about the 1 minute mark? It enters the view from the upper right-hand corner of the screen, then exits the same way out. Obviously there were birds flying about that morning - you can see them down lower toward the ground. I have watched videos of where eagles or other raptor-type birds have been trained to take down a drone by flying down from up above it and grabbing the body of the drone in the very center - keeping away from the props, of course. Some of those birds are very territorial and will go to great extremes to protect "their area" - especially if they have chicks somewhere near.
 
Has this ever happened to you? Is there any reason DJI wouldn't honor the warranty?* The AC was flying smoothly using the AutoPilot Waypoint mode of a 9 hole mission. The AC suddenly fell from the sky at the halfway point of the mission with 60% of battery life left, at about the 11th minute, from an elevation of about 40 meters during the peace of dawn. I can see no apparent cause of the crash. Attached are (1) a screen capture of the completed flight route when the crash happened, and (2) a compressed zip file with the log data of the flight. This YouTube video shows the flight up to the crash:
Please forgive the soft and grainy quality of the video. It is from my iPhone which videoed computer screen running the recovered video. The video file was truncated because the recording wasn't properly turned off as a result of the crash. The recovered, but unstable, h265 file format video can only be viewed with VLC. There doesn't seem to be any other way to convert it. Most of the (iPhone-recorded) video is sped up 2x. The video speed is then back to normal just before the crash, which actually happens at about 10:44 (mm:ss) of the raw video. In this sped up version it happens at about 5:28. (I'm still trying to fully recover the video. The lighting was perfect for post processing.)
Music: Clouds by audionautix.com
*DJI Thailand says it needs to be sent to Hong Kong to analyze. It could take 2 months before any decision on what my options are.
 
Sorry for your loss. One thing I became aware of when I regularly flew my first P3P was after a mid to long flight 10-20mins duration and doing a post flight check I found the props would be warm and sometimes hot. Now I live and fly in Thailand, so its mostly hot days here anyway but even on the cooler days and early evening flights for sunset vids they would be warm to touch. I know on more than one occasion I had to retighten one or two props. Then I started to use the prop tool and give it 1/8 more than finger tight every time. Since then I have never had this problem. I can suggest that maybe one prop might have warmed enough to become loose and ultimately come off. Just a theory but very real if combined with stick control movements at the critical time.
 
I did a test some time back to see if suddenly slowing a motor (active braking) could make a prop fly off. I installed a prop as loose as possible and manually grabbed the motor bell at different speeds. I found that it was nearly impossible to make this happen. Just starting the motors would snug up a loose prop pretty well. Only at the very highest speeds, with a completely loose prop was I able to make one fly off. I also tested the effect of losing one motor phase as would happen with a disconnected wire or ESC glitch. In this case the prop would fly off instantly and consistently even if it had been installed pretty snug. I think this is more likely the cause of many of the prop loss crashes that were blamed on props not being installed tight enough.
At times in this video, the prop looks like it is moving slowly but it is just turning at a rate near the camera's frame rate. At the end of the video, you can see what happens if you disconnect a wire and lose one motor phase. Obviously, this was not a P3 but the physics should be the same.

Great test, @syotr! Thank you very much for sharing this.
 
Sorry for your loss. One thing I became aware of when I regularly flew my first P3P was after a mid to long flight 10-20mins duration and doing a post flight check I found the props would be warm and sometimes hot. Now I live and fly in Thailand, so its mostly hot days here anyway but even on the cooler days and early evening flights for sunset vids they would be warm to touch. I know on more than one occasion I had to retighten one or two props. Then I started to use the prop tool and give it 1/8 more than finger tight every time. Since then I have never had this problem. I can suggest that maybe one prop might have warmed enough to become loose and ultimately come off. Just a theory but very real if combined with stick control movements at the critical time.

Hi @Rob65. This was flown in Thailand, too. But at 6:00am, and about 28C. I don't notice any significant warmth in the props after flying here. In fact, the props seem tighter and require more effort to remove after flying 10-20 minutes. But thanks for the suggestion. I will consciously tighten more than finger tight next time. Do you think that will cause more wear on the prop thread, though?
 
Not just you. Shortly after they were released, I had one freak out on me. Confirmed by DJI that it was their technical glitch and they warranty repaired it for me at no charge. Edited to add that this was an area I regularly flew in.

Great to know. Thanks for sharing!
 
Can you check if the front right ESC did fail? Even if you can't power up the aircraft, you can check if all the connections look good. If it was ESC failure then DJI may well be willing to repair or replace under warranty. You just need to be able to demonstrate that it was not user error, such as an improperly attached propeller. I'm not sure whether @With The Birds's observation regarding the motor design means that these motors behave differently than demonstrated by @syotr, but it's probably worth pursuing anyway.

I had to send my P3P to the dealer for their inspection prior to any action on the warranty. It's quite likely they will then send it to DJI.
 
I think, from a "warranty hopeful" perspective, you may be facing something exactly like this:



We can try to do the best we can to analyze everything for you but in the end, they will decide whether it's covered or not.

I truly hope they cover it for you and hope they explain why!

Me, too. Thanks for your, and everyone else's, contributions to this post.
 
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It's between the camera and the landing gear - it would have to be perched on the horizontal strut. That would be one crazy bird. It's not a bird.

@hwortman, @sar104, @Jthomp, LOL! sar104 is right. It's not a bird. It's the edge of my iPad cover. This video was from my iPhone camera recording my laptop running the recovered video on VLC. (The video was truncated because the camera didn't shut down properly. I could only recover the video in h.264 format, which only VLC could play.) My phone was resting on my wife's iPad because it has a flexible stand (mine is fixed angle). But her iPad is white, so I tried to use my black iPad to cover the reflection. But it went into my iPhone's range.

I've since discovered how to record the screen directly. This is a version without reflections and iPad cases coming into view.
 

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