I had my first loss of control crash today, I'm running 2.91 on an APM2.5 quad.
I'm using a frsky module in a turnigy 9x radio running er9x, and the receiver is a D8RII+ running the new 27ms firmware in PPM mode. I have had about 10 hours of trouble free flight with this rig until now.
I was in alt hold mode, when I noticed that it had stopped responding to my yaw input, so I tried switching back into stab mode, but it didn't do anything. I then tried flipping the RTL switch, and that didn't work, so I finally turned the radio off, which put the rx into failsafe mode and output a throttle value of 990us which triggered the throttle failsafe and initiated RTL. The tlog shows that at 74.7% basically all of the channels stopped updating, and it switched me into loiter mode. At 82.1% the throttle failsafe RTL was enabled by the TX being powered off.
Unfortunately when I powered it on, I was about two metres from the house, and so when it RTLd, it ended up coming down very close to the house and hitting a wooden beam on the way down, which bumped it into the side of the house and broke all the props. Luckily it seems like that's the only damage!
I have my tlog uploaded here: http://www.droneshare.com/view/dobyrdz
My suspicion is that the tx stopped sending valid data somehow, but I'm not 100% sure. Can someone in the know please take a quick look at the tlog. I'm grounding this quad until I can get to the bottom of it.