Here's a tip: Don't fly one into the side of your house.
Top rear motor failed, I think, but that doesn't explain it, exactly. I've test flown on 5 motors before, briefly, and this was not that. Anyway, all I really know is that in Stabilize mode and hovering the nose pitched up and I couldn't get it back before it flew about 60 ft backwards to find my house. I almost got it on the ground before it hit, but not quite. The top rear motor was stripped off of its mounting screws when I picked it back up, so maybe the motor came off in flight, but that doesn't seem likely. The prop on that motor doesn't even look damaged. It still should have flown alright instead of pitching uncontrollably. If the top motor hopped off and blocked the lower motor, it should have flipped instantly, not flown backwards at a 20degree pitch. Who knows.
I have been dealing with HDOP over 2, and so was only using Stabilize mode. Log confirms it was in stabilize the whole time, and the pitch wasn't requested. At least that's what I see from the log.
So, I'm going to order a new GPS, and mast, install some of my spare motors, order some more props, and resolder the antenna on the air side radio (vs. buy a RDF900 for ground use). Recalibrate ESC's, Compass, and Accelerometers, do some vibration testing to check the other motors out, pray, and then it will fly again!!!