Weird flight... Could use some advice

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Hey everyone. Been reading these forums for over a month, but this is the first thread I've started. I have a P3P and close to 30 flights under my belt. My history is with fixed wing aircraft, so P-mode was never an option. That being said, ive only flown the phantom in P mode and it's amazing.

That brings me to today. I took my first two long range flights out over farm land. The first flight I went out 2 miles, turned around and came back just to realize the record video button didn't "take" so it didn't record.

I went home, charged back up and did the same flight again. Though this time, I had a considerably stronger headwind (10 mph or so.). I took the phantom out and hit the 2 mile mark and began to turn around.

I did not let off the throttle (50%) and simply started a slow turn around. About half way through the turn, the iPhone started screaming "ATTI mode" at me. I saw "compass error, switch to ATTI mode" flashing across the screen. I switched off of the map view and back to fpV to see that the bird was flying at about a 45% horizon. I self corrected this and toggled the switch in a panic all the way to F mode. It yelled at me for not having multi flight mode enabled, and I switched it back to P-mode. After I switched back to P-mode, everything was apparently back to normal. No more issues. The bird was still 1.5 miles out, but flew back normally.

My question for you brilliant folks is, could my turn that I initiated at around 20-25mph combined with a strong headwind have caused the compass error? I did a very similar flight with a very similar turn speed an hour before, the only difference being the stronger headwind. I also calibrated the compass in the same spot before each flight.

Thanks in advance folks!


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My question for you brilliant folks is, could my turn that I initiated at around 20-25mph combined with a strong headwind have caused the compass error?

I doubt it. I've flown in high winds doing circles, figure 8s, etc. without a compass error.

Did you calibrate the compass before flight. Did you go near any cell or radio towers?
 
Yep. Calibrated before each flight. I didn't see any cell towers or power lines close to the bird in the video when I turned around.


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To note, wind speed was probably 10 on the ground. Phantom was at 300 feet. So undoubtedly much strong winds.


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Upload to Healthy Drones.com and look at the flight records and see if compass turn was within spec. or if the issue even coincided with the turn towards home.

It will display the wind vector also.
 
If you don't move more than 100 miles from the last compass calibration it's best not to recalibrate. Stick with a field calibration that works for you. If you have an issue with compass, recalibrate and leave it alone unless you have an issue.

I've recently had the same issue about 30 seconds into my 3rd flight from the same spot. Unexplainable.
 
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Sounds like some type of interference. I had the same thing happen once in a location that I've flown many times before.
 
Thanks for the advice so far guys! I will download the dat file tomorrow and upload it... First time doing that. I guess my biggest worry is, now that this has happened to me should I have any worry about the health of my quad?


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I don't believe that the turning or wind to be an issue, I have been caught in 40 MPH wind with no issues but moving slow as hell. I only do my compass one time, even though DJI says to do it every flight, it is the general consensus here that the more you do it the the more something can go wrong. Always do it away from any metal, out in an open field. Unless I go 50 /100 miles than I will redo the compass calibration. Always good to check your compass mod valve on the Go app before each flight, it should read around 1500, if it doesn't then you should recalibrate the compass. Sounds like some kind of interference, I would take a relook at that area just to see if you see anything that could have possibly cause it.

Also learn to fly in ATTI so if and when something comes up you can fly it back manually, does take quit a bit of practice in the wind to master.

Out of over 400 miles of flight time, I had a compass error a couple of times, one was electrical interference and the other I never figured it out, so just be careful flying in that area in case it comes up again.
 
Thanks folks - went through the effort of downloading the .dat file from the Phantom, only to realize that isn't what Healthy Drones wants :) Would you please take a look at the following flight log and see if you can help me figure out what happened?

HealthyDrones.com - Innovative flight data analysis that matters
I don't see anything weird, it was changing a lot from Atti GPS and Atti. Out at 9K feet, and to change your settings to multi flight, which I would go ahead and change that setting in the Go app. Just case it happens again. You were sure bookin it at 57 MPH [emoji4] Maybe someone that uses Dashware can get more information on what may have happened here. Didn't see any towers or anything, just some double power line poles quite a way back in the middle of the flight, which could b a possibility?
 
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I don't see anything weird, it was changing a lot from Atti GPS and Atti. Out at 9K feet, and to change your settings to multi flight, which I would go ahead and change that setting in the Go app. Just case it happens again. You were sure bookin it at 57 MPH [emoji4] Maybe someone that uses Dashware can get more information on what may have happened here. Didn't see any towers or anything, just some double power line poles quite a way back in the middle of the flight, which could b a possibility?

Haha - I was NOT booking it - curising around 25MPH. Then when it switched out of P-GPS and into ATTI, it started hauling butt! Didn't even know the thing could go that fast!
 
Haha - I was NOT booking it - curising around 25MPH. Then when it switched out of P-GPS and into ATTI, it started hauling butt! Didn't even know the thing could go that fast!
Yeah that crazy because you only show wind gusts of 14 MPH, I've flown in pretty high wind, like 40 and would hit like 47 MPH with a tail wind. Hey you may have a photo type model with a turbo [emoji15]LOL
 
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Thanks folks - went through the effort of downloading the .dat file from the Phantom, only to realize that isn't what Healthy Drones wants :) Would you please take a look at the following flight log and see if you can help me figure out what happened?

HealthyDrones.com - Innovative flight data analysis that matters
The .DAT file will tell you a lot more about the flight. In particular, the compass X, Y, Z, and MOD numbers can be seen. Since you've already retrieved the .DAT can you post it via DropBox. If that doesn't work for you then upload it to FLYXXX.DAT and tell me the name of the file and I'll retrieve it and DropBox it.
 
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The .DAT file will tell you a lot more about the flight. In particular, the compass X, Y, Z, and MOD numbers can be seen. Since you've already retrieved the .DAT can you post it via DropBox. If that doesn't work for you then upload it to FLYXXX.DAT and tell me the name of the file and I'll retrieve it and DropBox it.

Thanks Bud! I uploaded FLY046.DAT to FLYXXX.DAT - please let me know if that is all you need.
 
On a positive note, I would like to state that with no mods (not even windsurfer) I went out just over 2 miles and had video stream the whole time :)


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Nothing to do with the wind. Your last calibration was bad. Repeated calibrations are pointless and as you can see from this, dangerous. Read this to see where you might be going wrong: Compass Calibration, A Complete Primer | DJI Phantom Forum

Thanks Ian,

I have done the calibrations many times and ensured all items were out of my pockets, etc - and was away from even the controller when I did it. Was there anything in the logs that suggested the calibration was bad? And if it was bad, why was it only bad for for 30 seconds? Tracked in a pretty straight line other than the 30 seconds it "freaked out."
 
That's common in a bad calibration or bad take off point. The reaction is delayed typically until there is a big turn. Somehow that calibration didn't work well.
 
That's common in a bad calibration or bad take off point. The reaction is delayed typically until there is a big turn. Somehow that calibration didn't work well.

Well that is incredibly comforting news actually. A good re-calibration should fix this then?
 

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