P3A crashed, please help analyse what caused it?

[sar104]

It obviously did not lose its battery since it continued to transmit telemetry. It also doesn't look like it lost a prop - the onset of the problem was too gradual, starting with an uncommanded yaw to the left at 245 seconds. The first full rotation took nearly 8 seconds, after which the uncontrolled pitch and roll excursions started, with an overall frequency of approximately 1 Hz. That was also the point at which the aircraft began to lose altitude. Really do need the DAT file to figure this one out, I think.

 

[happydays]

Agreed. Possible bird strike? .DAT should rule out anything else.

 

[sar104]

Agreed. Possible bird strike? .DAT should rule out anything else.

I'm not sure what a bird strike might damage, other than a prop, that the aircraft could not recover from.

 

[WesleyR]

Hi guys, here is the a link to the last 2 dat files that he could retrieve.

Thank you so much for the assistance thus far, much appreciated.

Dropbox - Drone

 

[happydays]

I'm not sure what a bird strike might damage, other than a prop, that the aircraft could not recover from.

It could start a tumble which the quad would find it difficult to right itself from.

 

[sar104]

Hi guys, here is the a link to the last 2 dat files that he could retrieve.

Thank you so much for the assistance thus far, much appreciated.

Dropbox - Drone

Neither of those files is for the flight in question.

 

[sar104]

It could start a tumble which the quad would find it difficult to right itself from.

Maybe in some circumstances, although they are really pretty good at recovering. In any case, this started with a relatively slow yaw event, and there is no way that was unrecoverable by a fully functional P3.

 

[pe9999]

Data looks like a prop broking in mid air. Just not sure how and what causing the break.

 

[sar104]

Data looks like a prop broking in mid air. Just not sure how and what causing the break.

I'm not sure about that - the problem seemed to develop much too slowly for it to have been a catastrophic mechanical failure. It's unfortunate that the DAT file was apparently not recoverable.

 

[pe9999]

Without access to the AC, we are all guessing.

 

[sar104]

Without access to the AC, we are all guessing.

Well not completely guessing - we have the mobile device log and the OP has the AC which he said has all its props, although no comment on whether they are all intact. What the mobile log lacks are the motor performance data that would likely show definitively whether any of the props broke or detached, and the raw accelerometer and gyro data that would define the event more clearly than just pitch, roll, yaw and velocity.

 

[WesleyR]

Thanks for all the help this far guys. My friend is trying to see if he can recover any other log files from the aircraft but I'm not too hopeful.

Attached is a pic of the props that he sent to me, he was using carbon fibre props at the time.

View media item 3812

 

[macoman]

Thanks for all the help this far guys. My friend is trying to see if he can recover any other log files from the aircraft but I'm not too hopeful.

Attached is a pic of the props that he sent to me, he was using carbon fibre props at the time.

View media item 3812

I hear bad things about the use of carbon fiber props. Apparently they are not reliable and it's recommended to use the OEM props.

 

[WesleyR]

I've read that recently too.

 

[Frank3447]

Hi guys

A friend of mine flew his P3A last weekend and on returning his bird fell out of the sky and crashed into a park. I can see a "Speed Error" before a "Compass error", any ideas?

Here is the log : DJI Flight Log Viewer - PhantomHelp.com

Many thanks

Could somebody have shot it down or used some form of interference device I have heard company's are using such tools to protect there space.

 

[happydays]

Carbon props have never been good for the Phantom range since they moved from bolt on props to pre-threaded ones. It's always a source of amusement every few months when someone comes on here and asks which are the best CF props to buy, or the best tri-blade props to buy or similar.

It's well known that OEM props are the best, are pretty well balanced out of the packet and are pretty cheap too.