Hey everyone, new to DIYDrones.
I built myself a quad using a Pixhawk for my first drone this year, and apart from a few quirks, it seems to work quite well. I am a tech savvy person, so for the most part, it was fairly straightforward. I am using the T4 by Brendan22 (http://www.thingiverse.com/thing:261145) with jDrones 880Kv motors and 10x4.7 APC Slowflys, jDrones 20 Amp ESCs and a Multistar 5200mah lipo, carrying a Tarot 2d with a GoPro.
As mentioned before, I am using a Pixhawk with all the trimmings (GPS, and Telemetry radios, current monitor).
Everything has been working well, but this weekend I had an inexplicable crash that resulted in my poor little guy coming to rest 3 feet under the surface of Turtle Lake. Fortunately, the only damage is a burned out ESC (which may have been my fault, since I didn't bother to drain the water out of the heatshrink before trying to test it later that day). Everything else, including my Pixhawk, seems to be fine after some drying.
It happened as I was flying quite some height above the ground in Loiter. It was flying fine as it usually does, and I reduced throttle to bring it down a little bit. After setting mid throttle again, I applied a fairly strong roll to move the drone out in front of me, which seems to have triggered a pretty steep descent. I let off the roll and gave it full throttle, but it just didn't seem to recover, and I watched with horror as it splashed down into the lake.
At first I thought it was a Vortex Ring State since it occurred after a descent, but I've been looking over the logs and I'm not so sure, since it does stabilize after my initial descent, it only starts to lose altitude after I moved it laterally. After looking at the log, it looks like the Pixhawk didn't have any GPS glitches or funky Altitude readings, it just simply starts to fall from the sky. The Pixhawk applied full throttle long before I ever did, but it just simply didn't recover. There doesn't seem to be a voltage drop or change in current to indicate a battery problem, but there is quite a departure of Roll and Pitch from DesRoll and DesPitch which, to me, indicates that it did go into VRS shortly before hitting the water, but I still can't figure out what triggered the descent.
Anyway, I've pored over the log and I can't really figure what happened. I have attached it, and if anyone would have a look at it for me, it would be very much appreciated.
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