Went to fly this morning and had a weird event occur.

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This morning, like most, I set up at a local field. It is located behind a middle school and this was my last chance to use this location before school starts up again.

I first flew my Radian for three batteries worth and had no unexpected results. Successful launches and recoveries.

With my P2V+, I did all that I usually do. I had my Phantom well away from everything. I had recently pulled the cover off and checked the condition of some mods I had made to ensure wires weren't chaffed by their original placement. All was pretty good. None of the foam materiel I had utilized had degraded. I have the newest motors and ESC's. I also did the DJI dance and used my wood table properly balanced and laptop to compare the various values and all were well within limits. Since my wife had placed my DJI case within 1' of our sub-woofer here in the house for our home theater setup, I felt the need to ensure the compass calibration and IMU Advanced Calibration was good. Both were. The IMU here in the house where I've always done it and the DJI dance in this field where I've cleared of all metal with my metal detector. As I said, NO metal was anywhere near where I did the DJI dance this morning.

The moment I took off, with authority to get the bird off the ground and into my 10' hover for a HL point to be set, the P2V+ V3 suddenly went into RTH mode. How did I know this? It went to the preset 150' altitude I use for clearing the tall pine trees in my area. It then moved roughly 10m North and 25m West which was the LAST place I had set a good home lock point just two days ago.

I'm quite confused since I had done a BTU reset and complete IMU calibration. Then the DJI dance within minutes of this flight. I did, of course, power down everything and restart after doing the last dance this morning.

As the Quad went off to the previous HL point, I placed the TX into ATTI mode and flew it back. I did allow it to go to the last HL point first, where it came to a 150' hover since there was nothing at that altitude that would interfere with the flight path. As soon as it stabilized, I switched to ATTI mode and brought it right back to me despite the 20mph winds. I had plenty of battery power by the time I brought her back to me. Over 80%.

This is the first time I've had an un-commanded flight occur. I'll have to keep looking into this, but wanted to know if anyone had experienced something of this type in the meantime. I flew her out of my backyard just 45 minutes ago and everything works just fine. I'm just confused as to what happened this morning a mere 750 meters from my home in this field.
 
Two suggestions:

- You should always make sure your home point has been marked before takeoff. Check the map to ensure the home point is at your current location.

- Don't dance just to dance. There is no need to obsessively calibrate your compass before each flight. Do it per this guide:
http://www.phantompilots.com/threads/compass-calibration-a-complete-primer.32829

The only reason I did the dance was because I had done an IMU Advanced Calibration. I typically do not do a dance unless I've moved a good distance and the Axis numbers are off.

I had gotten the second set of green flashes almost as soon as I came to my 10' hover. I get GPS lock VERY quickly here. Usually have 7 Sats within a minute and 12 within two.

Thank you VERY much for your insight though. The more I think about it, the more I think something outside of my control came into play. I'm looking into it now with the County Sheriff's office. I've flown from this field so many times in the last two months I've had this bird that I'm thinking SOMETHING must have changed outside of my control.
 
I'm looking into it now with the County Sheriff's office.
Work must be slow where you are if they have time to troubleshoot Phantom issues ;)
 
Work must be slow where you are if they have time to troubleshoot Phantom issues ;)

I do a lot of metal detecting for them. So I know a few of the deputies. I put my name out there for them to call when vacationers lose stuff like keys and such. I've recovered quite a few things for them making the deputies look good. So they give me good deeds in return. ;)
 
Yes, did the whole power cycle dance as well as the DJI dance.

I may have my issues figured out. Once school resumes, which is less than 48 hours here now, the County initializes the cell tower right out side of the school.

After flying from this field all summer long, I'm left thinking certain security measures being enacted caused my malfunction. The follow on flights, I've done two since this morning once batteries were recharged, leads me to believe I've got it figured out.

Thanks for the input!
 
I'm confused here but sometimes that's not hard to do.

I didn't think it would remember a previous home point after being powered off. Is that not the case?
 
my flight log shows HL gps coordinates 0,0 before it is set. my phone app DOES remember last HL, but that has nothing to do with next flight...

you said you got 2nd set of green blinks, so a NEW HL was set, so no chance of prev one being used too.

you said it went to 150ft AND STAYED THERE? my rth goes to height, to HL, then immediately begins o decnd.... i doubt this was rth?

Do you have a flight log?

did you try to bring it back IN GPS mode BEFORE switching to ATTI? What happened?

It would be GREAT if you could figure out what happened and share it!
 
I'm not sure it went towards the previous home point now. When I switched to ATTI to try and bring it down and towards me, the wind must have pushed it.

I've flown in another area close to my home and had no such issues at all. Was up early this morning and flew in a construction site where all the land has been cleared but no workers.

Evidently, the repeater station was activated over the last couple of days and that tower was within 150m of where I took off. I'm not sure why the Quad went to RTH altitude and moved over the way it did but I'm assuming it was wind push. In thinking the events through, I believe I went to ATTI mode as it rose to roughly 150', then switched back to GPS and when I couldn't get it to come back, hit ATTI again as it stabilized at altitude. I'm just glad I was able to get it under control.
 
yes, glad you got it back. Does not sound like a likely or single culprit will be found for the bizarre behaviour that day. Live and learn and gain more experience as we go and hopefully our bag of tricks will save us when that day comes. I think if it was me I would have switched from GPS to ATTI then right back to GPS just AS SOON AS IT STARTED TO RISE WITHOUT MY SPECIFIC COMMAND. That might have cancelled any RTH or other something taking over right away. Just a thought.
 
yes, glad you got it back. Does not sound like a likely or single culprit will be found for the bizarre behaviour that day. Live and learn and gain more experience as we go and hopefully our bag of tricks will save us when that day comes. I think if it was me I would have switched from GPS to ATTI then right back to GPS just AS SOON AS IT STARTED TO RISE WITHOUT MY SPECIFIC COMMAND. That might have cancelled any RTH or other something taking over right away. Just a thought.

Yep, I should have switched to ATTI sooner and left it there. Live and learn.
 
Quick question what does the BTU do what's its purpose on the phantom thanks
 
Quick question what does the BTU do what's its purpose on the phantom thanks


You can complete a total Compass re-calibration using the BTU reset. This will allow you to complete a reset of the compass that then allows you to reset the entire system. I don't know why it does this, I only know it does.

Once you do this reset, on a completely level surface as described, your Quad will be required to also do a reset in the filed. As in, you'll be required to do a new DJI dance.

If you've been having issues with your quad hovering around more than a few meters, this will help you reset the quad to a more exacting area. Look to my other posts concerning how to do this.
 

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