My copter fell from the sky today.  Not sure what happened.  I think it's like a guy who posted a crash log a day or so ago, it looks like power failed suddenly. 

I don't know how the power plug could have come loose (xt60), but that's my best guess.
The smashed battery still works. 

If anyone has a minute, could you review my log and let me know if you notice anything?  This is my first crash analysis, but I didn't see anything odd before it lost power.   Some things are logged for some milliseconds longer than others, but I'm guessing that's normal.   There was a small increase in current draw, right as it stopped, but I think it looks w/in the normal range..

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Look's what I tell you in the other post, your log is interrumped so something happens to your board that stop logging, probably a brown -owt, read here, perhaps help you http://copter.ardupilot.com/wiki/common-diagnosing-problems-using-l...

Hi I'm the one who just posted the same issue yesterday and it happened also this day.

I had a very similar issue. My Flip FPV worked with the same config for many flights, some aggressive, without any issues. I just changed the receiver config a bit to make it cleaner but nothing seems wrong and it works fine (even after the crash). I still cannot find the real cause :o(

My Flip is supposed to be "indestructible" but a 38m fall on grass and mud broke all 3 frame plates, bent a standoff, crushed the GPS module (still works!) and bent my brand new Feiyu G3 gimbal. Plus some mud everywhere...

Firmware issue!!?? (this will create some debate ;o)

oh I forgot, as I said in my post, I was flying FPV and saw the minimosd display reboot just before the crash. This thing is quite sensitive so I thought it was just a normal glitch but maybe it was due to an APM reboot ???

A log?

I don't know if it will work but: http://diydrones.com/xn/detail/705844:Topic:2053548?xg_source=activity

Otherwise just check my latest posts

Hi, I really don't know what could have happened in my case.  
The battery was firmly plugged in when I took off.  All the other power and motor connections are directly soldered, so nothing disconnected or shorted there.  The battery didn't fall before the copter.  The battery is very smashed, but still tests properly, so it didn't suddenly die. 
I was hovering, not moving.  I had recently slowly spun around the yaw axis, but nothing that should have pulled anything loose. 

But......  I haven't seen a lot of other people with the same issue.  It's hopefully just a coincidence that it happened to us around the same time. 
I'm thinking about installing a small backup battery taped directly to the pixhawk, so if it happens again, I'll either get a log or know it's an issue w/ the flight controller itself. 

My copter didn't survive the crash either.. 25 meters onto concrete. Lost a brushless gimbal, a motor, the entire frame, a small pan/tilt servo gimbal..  The gopro, sony ccd, and pixhawk all appear to have survived.

If anyone has any ideas about what could have caused it, I'd appreciate hearing them.

Look at my post in my discussion thread. Found link with sband radar station, at least in my case.

Typically radars broadcast at relatively high wattage's, any of the weather radars could easily knock you out at even greater distance.

S band is the obvious one, but harmonics and just plane signal amplitude could still take you out on the higher frequency ones as well.

On the SF Bay bridge there is a large weather radar and it is at least somewhat notorious for "possibly" producing cataracts in the eyes of the operators.

Not really good to spend that much time around that much power.

And certainly not a good thing to fly anywhere close to.

Best,

Gary

Wow, glad you found something. 

I don't think that's the issue in my case.. I hope not, because I was flying in my yard, and hope I'm not being blasted by high power radio waves here. 
Weather radars are large, right?  I'd know if I lived by one?

I do live by a communications tower..  I've seen them knock out wifi, but this wasn't signal loss.. it was a reboot, which I would expect would take more power.  And, I hover in this same spot all the time.. My yard is small, so I don't have many options for taking the thing up for a test flight.. It's always this same spot. 

It's really a horrible way to lose my craft.  I was sure some day I'd crash it and learn from the experience.  But for it to just fall from the sky w/out any logs or clues as to what happened is devastating.  (not to mention the $$$ and month of work it will take to repair.. she was a large bird!). 

Yes it would take serious power to cause a hardware reboot, so it probably isn't that.

Although it is somewhat possible that the RF could interfere enough with your own RC enough to cause some kind of illegal condition that could cause the firmware to crash.

And yes weather radars are large, you'd be aware of one near by.

Frankly I wouldn't want to live to close to the sweep of one of those things with or without a multicopter.

More likely it was caused by a temporary loss of conductivity in one of the many connectors.

This happens most likely from vibration or shock on a somewhat loose connector terminal.

All connectors are problematic, but some are better than others, some people go to a lot of trouble to hard wire everything, but of course that makes it's own problems (like maintainability).

Temporary shorts can also cause a reset as can the firmware performing an illegal operation (crashing).

Best,

Gary 

OK, thanks everyone. 
I guess I will not worry about a flight controller glitch, and will assume it was my battery connection or a short...  I'm rebuilding it w/ cleaner, secured wiring, and will definitely tape my battery connector together before take-off. 

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