I flew my Falcon EPO FPV for the first time, its done many normal flights before on that aircraft. I had a co-pilot/spotter that was maintaining direct visual contact with the aircraft. The aircraft was only 700m away, One minute I had control, the next minute I didn't, the plane glided away into someone's backyard never to be seen again. I was using a Spektrum DX and AR8000 receiver. I suspect that failsafe kicked in when the receiver got interference.
This brings up some interesting points in relation to the policy of the modelling association in Australia. Firstly my flight was in accordance with its policy on FPV, there were two pilots and one had direct visual on the aircraft. Unfortunately that doesn't stop the aircraft from getting interference and crashing.
Ok, so why didn't the aircraft's failsafe engage RTL mode on my APM? Because I forgot to set it, my bad. Unlike the Futaba which I use for my Skywalker where you see the failsafe on the radio and even if you rebind it remembers it, on the Spektrum the failsafe position is the position of the radio at binding, I had rebinded the receiver the day before and its failsafe was to close the throttle and sticks at the neutral position.
But here is the interesting bit, the model aircraft association in Australia's policy (MOP44) rules out the use of internal navigation systems, RTL/RTH is a form of internal navigation that provides autonomous flight.
RTL/RTH activating on failsafe would have prevented the crash. Buddy box and co-pilot/spotter did nothing to keep aircraft from flying away and crashing.
Well I wasn't flying a modelling association airfield anyway, so their policies don't apply, it was my bad for forgetting to set RTH/RTL on failsafe.
Flight one - excellent, waypoint navigation was really good. Loiter motor power was a bit low.
Flight two - wind really picked up suddenly, but plane handled it well. Then my 2.4ghz booster failed. I list RC even though plane was right overhead. I struggled to take extra antenna cable off, but too late, plane was blown out if range. At same time my buddy was sending RTH command by mission planner, but xbees disconnected at less than 500m. There after I watched my fpv for 15 min helplessly as the ardu tried to loiter while being pushed further and further down wind.
Like you my receiver failsafe triggered loiter instead of RTH.
Despite, multiple safety precautions, a series of bad luck and incorrect failsafe setting made for a helpless situation