Mine did something similar the first time I used it. It passed range checks on the ground and then failed shortly after the start of a flight. I had it in a small rocket-launched glider with no esc, nor motor, nor other onboard interference source. The first flight, after I made one turn, the servo froze in one spot. Fortunately the model circled down with no damage. I checked all the connections, determined that the battery was still vigorous, and performed an extensive range check with transmitter antenna down, through which it worked fine. After launch, the servo again froze after I made one turn and remained in that position for about 30 seconds. Then, the servo suddenly went to an extreme position and the model spiralled in and destroyed itself. What are we supposed to do when a receiver can pass a range check but still not work in flight? How is that even possible? Is some signal that it can only pick up when aloft causing it to "automatically" reject the signal from the transmitter?
Robert Edmonds, Jr.
Herndon, VA