Our first test flight was conducted at a local field commonly used for FPV flights; it’s large enough to accommodate X8 landings, which was a significant factor in determining where to fly.
As I forgot my Ethernet cable, we weren’t able log any data from the I/O boards to the ODROID-X2—but it’s unlikely the data would have been of much use as we were still tuning CoG and none of the flights lasted very long. Nevertheless, we left the electronics in place and powered up since at that point it would have been more work to shut it all down.
The first launch resulted in a tight loop, as the CoG was placed too far back. Since there was no damage, we shifted the main battery forward and tried again.
The second launch was successful, but the plane was almost uncontrollable and after less than a minute dived into a tree from about 30m AGL. The tree was one of the tallest of those adjacent to the oval, but fortunately recovery was accomplished with damage being limited to a few scratches in the fuselage and wings (less than 1cm deep).
After moving the main battery even further forward (wedged in front of the shorter carbonfibre bar running through the fuselage) we tried a third launch, which resulted in much more controllable flight lasting several minutes. At this point we noted the lack of roll control, as well as significant flex in the wings at higher speeds.
Landing took some time, as the approach needed to be lined up such that most of the oval could be used; after getting it on the ground, we then found out that the foam slides very well over wet grass, and the X8 didn’t stop moving until it ran into bushes at the north end of the oval. This broke the epoxy on one of the pitot tubes, detaching it from the fuselage, and given the light was fading we decided to end testing there.
Main learnings from the first three flights were: