Trouble with P3 Professional

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Murrysville, Pennsylvania
So i was flying at our hunting club the other weekend, i was following the drone on my atv and everything was going fine, i had to put another battery in it at one point and took off again, i proceeded back to our cabin and the battery was getting down to around 30 percent, i took off ahead of me and initiated a landing at our cabin, i was positioned about 400 yards away, as the drone was in landing mode and about 20 feet off the ground, i lost all video monitoring. I raced back to camp and was able to restablish a video feed, at this point the drone was flying crooked and it was reading a compass error had occured. i manually brought it in and landed (after much difficulty as the controls were not reacting properly) i touched down and the drone flipped over and the propellers wouldn't shut off. i had to shut the battery off to stop the motors. i pulled up the video file and found that when i lost signal with the drone, it turned to (go home) and flew directly into a tree causing a prop to break and hence why it was flying crooked, landed crooked (causing it to flip), and why there was a compass error?? My question is, whenever it is in "go home" mode isnt it supposed to use the sensors to tell if theres an object in front of it and fly over it? Luckily the only damage was 1 broken prop, i replaced them and the drone is flying normal again. I just want to know so in the future i can try and prevent things like this from happening again.
 
There is no sensor to avoid obstacles. You need to adjust your RTH altitude to make sure it's over anything in the way


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There is no obstacle avoidance on the p3. Also, you can use the CSC to shut down the motors in a situation like that.
Compass errors are not a result of running into something. Compass errors come about by having a bad compass calibration or huge electromagnetic interference. And if you ever get a compass error in the future, use the toggle switch to switch to ATTI(manual) mode. Good luck in the future.

Sent from my iPod touch using PhantomPilots mobile app
 
There is no obstacle avoidance on the p3. Also, you can use the CSC to shut down the motors in a situation like that.
Compass errors are not a result of running into something. Compass errors come about by having a bad compass calibration or huge electromagnetic interference. And if you ever get a compass error in the future, use the toggle switch to switch to ATTI(manual) mode. Good luck in the future.

Sent from my iPod touch using PhantomPilots mobile app
I believe that the aircraft going into a spin as a result of a prop breaking will show as a compass error. I remember reading about something similar. I could be wrong though.


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Electrical wires under a deck can cause a compass error. That happened to me yesterday.

Unfortunately no obstacle avoidance, set that RTH altitude high!
 
I believe that the aircraft going into a spin will show as a compass error. I remember reading about something similar. I could be wrong though.


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I looked it up and youre right. My bad. but it only happens if its spinning really fast. This is from the healthydrones.com compass analysis.
"Looking for rate of change in the compass of 25 degrees or more per 0.1 seconds. That's about a 90 degree turn in a third of a second, which is not normal.

Most aircraft don't turn faster than 15-16 degrees per 0.1 seconds.

Faster turns can be a result of extremly strong winds, a crash into an object (example of a crash), magnetic interference, or a bad compass."
Running some quick numbers shows your phantom would have to be spinning at 40ish rpm to throw the compass off. (I think. Im not super good at math)
 
I looked it up and youre right. My bad. but it only happens if its spinning really fast. This is from the healthydrones.com compass analysis.
"Looking for rate of change in the compass of 25 degrees or more per 0.1 seconds. That's about a 90 degree turn in a third of a second, which is not normal.

Most aircraft don't turn faster than 15-16 degrees per 0.1 seconds.

Faster turns can be a result of extremly strong winds, a crash into an object (example of a crash), magnetic interference, or a bad compass."
Running some quick numbers shows your phantom would have to be spinning at 40ish rpm to throw the compass off. (I think. Im not super good at math)
Loosing a prop in the crash could cause that spin though.


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Thank you all for the assistance, i foolish thought i remembered seeing that there was an obstacle avoidance feature on the RTH setting, but obviously i was wrong. Ill admit i made many errors that day when flying. My home point was probably a mile from my camp and had an altitude change of -100 feet or so at least. I set the RTH height at 375 feet but i think i will raise it even higher. Screw the FAA, right?? I opened a support line with DJI about the compass issue because it wont even calibrate now that i am home.
 
Thank you all for the assistance, i foolish thought i remembered seeing that there was an obstacle avoidance feature on the RTH setting, but obviously i was wrong. Ill admit i made many errors that day when flying. My home point was probably a mile from my camp and had an altitude change of -100 feet or so at least. I set the RTH height at 375 feet but i think i will raise it even higher. Screw the FAA, right?? I opened a support line with DJI about the compass issue because it wont even calibrate now that i am home.

I don't know if I'd "screw the FAA." If you have to go to such an extreme, you may want to set a different home point closer to where you are flying.


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Not that you would need this for a broken prop, but it may come in handy if your P3 sustains a bit more damage in a crash.
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Thank you sir, I'll consider it, so far my flying experience went from good, to bad, to really bad today. I think i messed up the remote during a firmware update...
 
"Screw the FAA, right??"

You are not going to screw the government by flying into airspace that is reserved for aircraft that have people in it.

Besides, setting a RTH height that is excessive will consume power that may be needed for the safe return of your aircraft.

T
 
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Thank you all for the assistance, i foolish thought i remembered seeing that there was an obstacle avoidance feature on the RTH setting, but obviously i was wrong. Ill admit i made many errors that day when flying. My home point was probably a mile from my camp and had an altitude change of -100 feet or so at least. I set the RTH height at 375 feet but i think i will raise it even higher. Screw the FAA, right?? I opened a support line with DJI about the compass issue because it wont even calibrate now that i am home.


I think you may have read that you should set the RTH altitude high enough to avoid all obstacles, it may also be of help to set the home point in an area where there are no trees or other obstacles anywhere near that position as I think you are pretty safe with the RTH altitude set to 375' unless you have some giant trees or skyscrapers near your cabin. Typically I have my RTH altitude at the default 30M (90') and I'm pretty safe where I live/fly... Good luck with future flights!
 

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