Flyaway with crash: What happened? What to check before next flight?

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My Phantom2 with FPV did suddenly crash:

It was a bit windy, but not too strong. I did fly a few minutes then landed again to switch on my GPS tracker, which I had forgotten.
Then I took off again and did fly a small normal pattern in my vicinity. Everything was 100% under control until the drone did suddenly dive and crash. Everything happened pretty fast and I had no good chance to avoid it. I'm not sure but I think I tried to avoid the crash by steering against.
This is the live movie:
Accumulator was 70%, remote control was charged full. There is no WLAN in this area. Mobile phone was not with me.
After the crash all props were still attached or besides the drone. Akkumulator was thrown out by impact.

I was lucky: all 4 props damaged, H3-3D-Plate broken, GPS-Tracker-attachment broken and Immersion RC 5.8 Ghz 25mW transmitter broken.
My GoPro survived without scratch, gimbal is only a little bit bent but is still looking good. Engines seem to work properly. Drone is blinking green after a while and when I speed up the engines and try to turn with remote control, there are different noises to hear (all testing up to now without props attached!)

Now my questions:
What could be the reason for the crash? (I did not recalibrate the compass before flight)
How to avoid such a crash?

What to test now before next flight after repair?
What is normally also damaged which I could have overseen?
Thanks
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I'm not an expert but it looks to me there was a motor or esc failure on the back left side, this (I imagine) can explain the sudden forward and right side movement.
 
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Remember, straightening the 4 arms that mount to the dampers will not correct any leveling problems with the H3-3D.
If after the crash, the gimbal is not level, you need to straighten the "I-beam" shaped arm the supports the gopro camera
between the control electronics mounted in the black box and the camera mount.
 

ianwood

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Definitely not a motor failure. Looks like it was going into a big TBE which would indicate compass problems.
 
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Where did you take off from? Is there anything metal in the vicinity?
 
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Hey pingo, welcome to the forum. I wish it were under better circumstances. :)

I may be missing something, but there's not a whole lot of information in the video. I find that surprising.

Can you connect the Phantom to the NAZA assistant and check (NOT CHANGE) to see how well calibrated the controller is?

I'll bet those props did a number on the grape vines... :(. Good thing it wasn't a school yard.

There is a Google search link in my signature which may help, maybe not with this, but in the future. :)
 
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Looks the start of a TBE before it crashed.
You say you turned on the tracker.. then took off again.
Should have re-calibrated the compass with the tracker on...
 
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Looks the start of a TBE before it crashed.
You say you turned on the tracker.. then took off again.
Should have re-calibrated the compass with the tracker on...
That was a big bowl. But, yep that could have been the issue.

What kind of tracker do you have and what frequency does it transmit on.

I'm pretty stumped.
 
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Sorry to answer late. I did not get any mail that there are new answers.

Takeoff was from a green lawn. No metal around.

My tracker type is a GSM/GPRS RF-V16

What is TBE?

" There is a Google search link in my signature which may help, maybe not with this, but in the future."
Which link please? The advanced IMU calibration link?

I connected the Phantom 2 to the PT2. You mean this? How to check the calibration?
Here a screenshot, what seems to be it:
Bildschirmfoto 2015-06-21 um 14.52.34.JPG
 
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Your compass mod should be about 1400. Do the advanced IMU and check it again. Ignore if it says it's too hot.
 
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Your compass mod is way out.
 
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Sorry to answer late. I did not get any mail that there are new answers.
What is TBE?

" There is a Google search link in my signature which may help, maybe not with this, but in the future."
Which link please? The advanced IMU calibration link?

I connected the Phantom 2 to the PT2. You mean this? How to check the calibration?
Here a screenshot, what seems to be it:
You will have to go into your alert preferences to select email notification. SAVE is at the bottom of that page.

TBE = Toilet Bowl Effect

Here is the search link which is at the bottom of all my posts. It's the one with the word "google" in it.
Enter your text in the middle of the page, NOT at the top.
https://cse.google.com/cse/publicurl?cx=014775389315664725445:ejku2ysgyhi

Your Compass(RAW) numbers should be:
0 +- 300 for X, Y, and Z;
1600 +- 200 for the MOD.
 
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OK thanks.
I found the notification mails in my spam folder.

Good that we found the reason. I will do the advanced IMU.
Just one question: Do I have to put the phantom 2 outside or can I perform the IMU indoors?
 
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I had the exact same thing happen to my P2. Mine almost crashed on busy road as it went out of control. I was able to gain some altitude before it turned around, flew backwards and then finally crashed. Luckily, I had a GPS tracker as well (Trackimo) and was able to recover it. Contacted DJI and they authorized repair. Just got it back and they fixed it like new. May have been a compass issue. On the P2, unless you OSD, you don't know how many sats you have for sure. Lights turn green flashing when the minimum has been locked onto. Now I wait maybe 30 sec after green. Then I take off, hover about 4-6', check for stabilization, ascend to maybe 20', check for stabilization and then fly my mission. Takes maybe a minute or so more, but it pays off! I now have a P3 and do the same thing. Selling my repaired P2!
 
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I had a similar problem and i am not sure why, I got my P2 last fall and never once had a flyaway or any issue with M.C. and controller untill 3 flights ago, I had flown it all winter in the cold in NJ and it is not summer so im wondering if maybe its not used to the head as I get the M.C. is to hot to calibrate error everytime but calibrate it anyway but even before and after I lost communication with the R.C. and the unit about 5 minutes or so into every flight and Ive been flying it everywhere from near my home to the middle of the mountains in up state NY and everytime about 5min into the flight it starts flashing yellow, I lose control and it goes into failsafe and auto lands? any idea what it can be? its very annoying and caused the gimbal to break which has been at dji for almost a month now but even after recalibrating over and over and flight with no gimbal just to see if the error is fixed it still is not? thinking about sending the whole unit back to dji and maybe just buying a solo.....
 
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I had a similar problem and i am not sure why, I got my P2 last fall and never once had a flyaway or any issue with M.C. and controller untill 3 flights ago, I had flown it all winter in the cold in NJ and it is not summer so im wondering if maybe its not used to the head as I get the M.C. is to hot to calibrate error everytime but calibrate it anyway but even before and after I lost communication with the R.C. and the unit about 5 minutes or so into every flight and Ive been flying it everywhere from near my home to the middle of the mountains in up state NY and everytime about 5min into the flight it starts flashing yellow, I lose control and it goes into failsafe and auto lands? any idea what it can be? its very annoying and caused the gimbal to break which has been at dji for almost a month now but even after recalibrating over and over and flight with no gimbal just to see if the error is fixed it still is not? thinking about sending the whole unit back to dji and maybe just buying a solo.....
Here's one of a number of threads on proper IMU calibration.
The IMU must be cool to calibrate properly.

http://www.phantompilots.com/threads/imu-calibration-and-warming-up.44925/
 
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After advanced IMU calibration my drone is flying again nice. Thanks.
Do I have to repeat the IMU calibration from time to time?
 
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