P3P freefall into ocean

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Strange that it came a fair old time into the flight. Could it have been caused by a bird strike for example?

Doubtful IMO, but not out of the realm of possibility.

Birds of pray may attack a UAV, however as one who has spent many many hours near birds in the air, most that are not in that category, upon seeing you come at them (if that is the case and time allows) instinctively fold their wings and drop. That's their form of collision avoidance.

OP, sorry for your loss, I feel your pain. Take solace that you flew safely, and were over nothing when it happened, (Unless we get reports of tragic fish injury).
 
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So sorry for the loss of your AC. And having seen so many threads on here beginning "I lost/Crashed/Fell out of the sky....etc." I always check my P3A between flights for cracks, missing bolts and loose props, so it's a "belt 'n' braces" pre-flight routine. Even more galling that you carried-out the same checks.:mad:. Hope SWMBO gives permission for you to purchase a replacement! :D

I am always rigorous on my preflight checks (have a lenghty list). So it's hard to imagin losing a prop in flight; but I appreciate everyone's insight. Already purchased a refurbished P3P. What is SWMBO?
 
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I think you're right. Either a lost/broken prop or a motor failure. Without the .DAT it would be difficult to distinguish between the two. But, almost certainly a propulsion issue. Looks like it happened at time 418 secs.
View attachment 70119
@rwparkinson I noticed you referenced HealthyDrones indicating a compass error. This always happens with a propulsion issue. When HD sees a rapid heading change it assumes that can't actually be happening and that the compass must be at fault. In fact the heading is changing rapidly because of reduced or no propulsion from one of the prop/motors.

This is very interesting and I understand why you think the freefall was initiated by a propulsion issue. Thanks so much for conducting this analysis. I guess the next question is whether or not this type of data can be used to justify a DJI discount on the purchase of another P3P. Have already bought a refurbished one; but would gladly return if I could get a better price. This was a very expensive failure.
 
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I am always rigorous on my preflight checks (have a lenghty list). So it's hard to imagin losing a prop in flight; but I appreciate everyone's insight. Already purchased a refurbished P3P. What is SWMBO?

SWMO - She Who Must Be Obeyed - Your wife or girlfriend, etc. :)

If you disobey, you'll be a victim of AIDS - Aviation Induced Divorce Syndrome.
 
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I am always rigorous on my preflight checks (have a lenghty list). So it's hard to imagin losing a prop in flight; but I appreciate everyone's insight. Already purchased a refurbished P3P. What is SWMBO?
Yep. Just hope it doesn't happen to me too, but of course there is always a chance of failure. Really pleased you've got a replacement.As others have said - She Who Must Be Obeyed ;)
 
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My wife and I always take our thick rubber landing [and takeoff] pad. It's 42"x 42", and gives us adequate protection against particle debris blowing up into the motors from the prop-wash.
We do a fair amount of flying at the beach, and have noticed a few others flyers, over the last few years, taking off from the sand.
I'm thinking this kind of exposure, over time, will do a number on motors, props, etc.
 
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"Self-tightening" props could possible become "self-loosening" props in the event of a sudden motor stop (as in siezed bearing) or (theoretically) a "violent air manuever" the caused that motor to slow down rapidly. Also possible that the prop broke through fatigue.
 
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Is there a point where you just replace the props even if they appear to be okay? Just curious. I know everything has a reasonable service life.


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This is very interesting and I understand why you think the freefall was initiated by a propulsion issue. Thanks so much for conducting this analysis. I guess the next question is whether or not this type of data can be used to justify a DJI discount on the purchase of another P3P. Have already bought a refurbished one; but would gladly return if I could get a better price. This was a very expensive failure.
I don't have any special insight about what DJI will do here. Except to say that they're actually pretty good when it comes to fixing ACs under warranty. I know others may disagree. In this case it can't be determined that the cause was improperly installed props; it could also have been either a broken prop or motor issue. If you run into some resistance, back up and ask a different part of DJI, e.g. call if you've been chatting.

I am curious. Does the event correspond with a sudden change in speed or direction? Would that be a potential cause of an otherwise intact prop coming off?
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In this incident there wasn't a sudden change in speed or direction.
upload_2016-12-6_10-53-33.png

upload_2016-12-6_10-53-54.png

upload_2016-12-6_10-54-6.png

The hairpin turn at the end was after the propulsion incident started.

I've looked at the motor data for several flights where there was a propulsion issue. With a few of these it's been clear that the prop came off because it was found close to the crash site. But, there was no any indication of being related to change of speed or direction. It's a mystery to me how a prop can just come off after several minutes of flight.
 
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I don't have any special insight about what DJI will do here. Except to say that they're actually pretty good when it comes to fixing ACs under warranty. I know others may disagree. In this case it can't be determined that the cause was improperly installed props; it could also have been either a broken prop or motor issue. If you run into some resistance, back up and ask a different part of DJI, e.g. call if you've been chatting.


In this incident there wasn't a sudden change in speed or direction.
View attachment 70184
View attachment 70185
View attachment 70186
The hairpin turn at the end was after the propulsion incident started.

I've looked at the motor data for several flights where there was a propulsion issue. With a few of these it's been clear that the prop came off because it was found close to the crash site. But, there was no any indication of being related to change of speed or direction. It's a mystery to me how a prop can just come off after several minutes of flight.

Thanks. I've uploaded your graphics to DJI on line support. Will keep you posted on my progress towards a warrenty replacement.
 
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Thanks. I've uploaded your graphics to DJI on line support. Will keep you posted on my progress towards a warrenty replacement.
l have to ask if you were using standard props or carbon fiber?
 
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Happy to announce DJI determined the free fall and loss of my P3P was covered under my warrenty. I would not have throught to contact them without the encouragement and technical assistance of everyone who followed this post. Now I have to return the refurbished one I purchased earlier this week. Hope to be flying again soon. Have learned what will never happen to me can in fact happen. This has caused me to rethink where I fly and what is below. I'm now likely to purchase insurance when my flight plan is not in a remote area. Thanks again to everyone. This story ended well!
 
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He probably lost an engine, like mine did, the whole engine assembly broke off, DJI replaced the drone but they never admited to the engine separating from the P3
 

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  • Kinda hard to blow off an obvious indication. "That must have occurred on impact, even though the logs show otherwise and my video caught the missing motor and prop coming down next to it..."
 
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I lost a P3 to seagulls a year back. It was a group and one dived down and attacked it. Probably broke a prop. All the video showed was a flash of orange leg in the DJI app.
 
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interesting to note -

simple google search on P3P prop failures and 1,000's and 1,000's of threads and articles come up with this issue. DJI knows and tried to fix with the changes in the P4/P4P. Can't wait until after Christmas, all these sales through walmart and other discount retailers flooding the market with inexpensive overstock of the P3/P3P's ... gonna be fun
 
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Why did you not calibrate your compass? That's put rather plainly in the manual. Just saying. That should tell you something about the error and the cause. Sorry fog your loss.

There isn't any way that compass calibration, or lack thereof, caused this crash.

The whole "compass calibration" is a vast source of mystery and voodoo on these forums. Any crash tends to get automatically ascribed to compass problems, when in reality, compass errors are likely extremely rare, especially in the P4 with its redundant systems. I recalibrate when the app I'm using, Litichi or Go, recommends it.
 

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