Bummed. New P3A Crashed. Pls Advise

messenger · Nov 11, 2015

Send your p3 flight log to the dji service center near you. I did mine im sure they'll do analys and extnd service to your p3a. God bless

McVenturesRC · Nov 11, 2015

jwegener said:
With all due respect I believe the vast majority of folks in this thread are confused about how self-tightening propellers work -- they will NEVER unscrew themselves. They ONLY tighten.

Thus I don't believe this is the cause of the crash we're discussing here.

Personally, when I'm setting up my drone I place the propeller on top of the screw/motor and give it a single "flick" with my fingernail to screw them on -- I do ZERO hand tightening beyond that. As soon as the drone is powered on, they're getting tightened. As as you take off they tighten even more.

There is literally NO case in which the motor turns in a way that unscrews the propeller.

I'd love to hear this explained more because it makes no sense, sorry folks. If the drone is staying in the air, there's a force downward on the air under it -- Even when you're descending, the propellers aren't actually switching direction of spin, they're simply spinning a bit slower so there's less force. But again there's ALWAYS a downward force so the propellers are ALWAYS TIGHTENING THEMSELVES, NEVER LOOSENING. If there WERE zero force pushing down, it'd be in free fall. To unscrew themselves there'd somehow have to be a negative downward force (i.e. Props reversing the direction of spin) so the aircraft in that case would literally be descending faster than a free fall. Or you'd have to be flying it upside down. Neither of these cases happen in normal flight.

Thank you for that thread. I'm glad you said something. I was convinced it had something to do with missing a minute little snug twist or hand tightening. I can say with 100% confidence I screwed the propeller on! It reached 100 feet high. Anyhow, thanks. Back to square one. What caused my bird to crash?

McVenturesRC · Nov 11, 2015

III% Streve said:
A failed ESC will not suddenly become a NOT failed ESC. If it fails it exhibits, for a brief time, the same thing as active breaking. ANY sudden slowing of the motor will give opportunity for the prop to keep spinning at the higher rate, even if momentary, leading to it unscrewing.

This isnt rocket science people!! And its just a theory for THIS crash. Although I have never been wrong in any other crash prediction. EVERY time a prop is missing and is found the threads are either in tact (it unscrewed) or stripped (prop strike). There are no other options!

Good points. I'm going on a salvage mission today for the prop. In tact or stripped? I'll let you know!

rene van der meer · Nov 11, 2015

First MCVenturesRC I hope DJI can help you out.
Reading this and all other posts and references about missing props I am warned to tighten them properly. Thanks for that.
Many people suggest active braking our power loss could stop the motors and the inertia unscrews the props. Could that be verified on the ground without causing any damage?

III% Streve · Nov 11, 2015

rene van der meer said:
First MCVenturesRC I hope DJI can help you out.
Reading this and all other posts and references about missing props I am warned to tighten them properly. Thanks for that.
Many people suggest active braking our power loss could stop the motors and the inertia unscrews the props. Could that be verified on the ground without causing any damage?

I might, but its somewhat of a random even, judging from the infrequency of the crashes. But I will see if I can produce something for chits and giggles. The hard part is forcing an active braking event without actually flying, yet not chopping your face off at the same time. And god know where a prop will go if and when it comes off.

McVenturesRC · Nov 11, 2015

Ok. I found the missing prop. It's 100% in tact. So it unthreaded. It was located in very close proximity to the crash site.

McVenturesRC · Nov 11, 2015

That's pretty disappointing. My mind and my gut say I did the initial twist, then held each motor and did a snug twist. Guess my finger tightening has to be more snug. Pretty subjective amount of pressure. Is what it is.

GreggC · Nov 11, 2015

I would still send DJI your flight log.

BudWalker · Nov 11, 2015

GreggC said:
I would still send DJI your flight log.

I agree with this.

McVenturesRC · Nov 11, 2015

Do I send them the flight log independent of sending the unit back? I contacted online support, but they deferred me to customer service. CS then put me into an electronic system for what I presume is to generate a RMA. So, should I just wait for the RMA and return it or try again to reach someone about the flight log?

Navigator181 · Nov 11, 2015

I hate to point out the giant rock quarry across from the road from where you were flying - the ground where you took off from could be full of iron or who knows what. I only saw it when I zoomed out. Sorry you crashed. Your crash could have been from prop loosening, but I sure would try to avoid the quarry regardless. Maybe thats just me being overly protective of my P3P.

JKDSensei · Nov 11, 2015

McVenturesRC said:
Ok. I found the missing prop. It's 100% in tact. So it unthreaded. It was located in very close proximity to the crash site.

Thank you for posting the facts. Many here will continue to insist that what you found is simply not possible. Not sure why, but it's a public forum. You get what you pay for.
It still is not proof positive that that is what happened. But it certainly lends credibility to the theory.

Still, since the prop could not come off from an impact (which would actually tighten the prop), it should be considered an issue with the Phantom if the "self tightening" props can come off during normal operation...imo.

Sorry for your loss and hopefully DJI will cover you. Good luck.

JKDSensei · Nov 11, 2015

McVenturesRC said:
Do I send them the flight log independent of sending the unit back? I contacted online support, but they deferred me to customer service. CS then put me into an electronic system for what I presume is to generate a RMA. So, should I just wait for the RMA and return it or try again to reach someone about the flight log?

Copy ALL your flight logs before returning the aircraft.
I assume you know how to do that?
If you post a copy of the DAT file I would be glad to take a look at it.
The DAT file located on the Phantom has the most detailed flight logs.

DJI service will retrieve the logs as needed once they have it. They do not assume the end user knows how to do that.

III% Streve · Nov 11, 2015

Navigator181 said:
I hate to point out the giant rock quarry across from the road from where you were flying - the ground where you took off from could be full of iron or who knows what. I only saw it when I zoomed out. Sorry you crashed. Your crash could have been from prop loosening, but I sure would try to avoid the quarry regardless. Maybe thats just me being overly protective of my P3P.

Your about 2 days late, and insanely off course!!

III% Streve · Nov 11, 2015

McVenturesRC said:
Ok. I found the missing prop. It's 100% in tact. So it unthreaded. It was located in very close proximity to the crash site.

Thanks for the update. Now I dont have to try to reproduce this myself!! Sorry you had to be the guy to make me right, but there is always someone!

JKDSensei said:
Still, since the prop could not come off from an impact (which would actually tighten the prop), it should be considered an issue with the Phantom if the "self tightening" props can come off during normal operation...imo.

Self lubricating bearing don't last forever! Because they obviously cant lubricate forever. There is a proper procedure for installing the props. Self tightening? Sure.. they do because of the direction of the threads. That doesn't mean there aren't addition steps to proper set-up. And it hardly means there is some hair-brain master plan by DJI to sabotage all their P3s either.

This was an honest mistake made by an honest man with integrity! And thats ALL! If I had the extra cash laying around I would buy him a new P3 just because he had the balls to post the truth!

Navigator181 · Nov 11, 2015

III% Streve said:
Your about 2 days late, and insanely off course!!

Insanely off course? I didn't see where the thread was closed, I also saw that the last reply was 21 minutes ago. So how am I late? Or did you just post that to gain your comment count? I read the thread.

III% Streve · Nov 11, 2015

The quarry couldnt have cause this even if it were a magnet farm as the crash was not compass related.

Navigator181 · Nov 11, 2015

I said in my original reply

"Your crash could have been from prop loosening, but I sure would try to avoid the quarry regardless. Maybe thats just me being overly protective of my P3P ".

It's my opinion and this is a forum. Thank you for pointing out how I am wrong. I'll keep in mind what you may think before I post again. Have a great day.

alokbhargava · Nov 11, 2015

What if one uses three whites and one black dotted prop? Will p3 fly? I know in such a case one wrongly used prop will unscrew in air. Total hypothetical case.

syotr · Nov 11, 2015

Per the original poster,all the motors stopped. The prop coming off was incidental and after the fact. Active braking might cause motors to slow quickly and might cause a prop to come off if it was very loose, but I would expect this to happen when flying aggressively. I hope DJI will be honest and replace your bird. It was defective.