Last Friday, I had my first training session. Fortunately, the club has a designated trainer and he has a Carbon Cub all decked out and has wireless trainer/student transmitters. For some reason (either not installed or not working) the SAFE feature was not available. My three flights during the day were without SAFE. He did take-off and land of course. I did the oval circuit around the field, with emphasis of maintaining altitude in the turns and then proceeded to do figure 8's. He said I did great, but these days, everyone gets a blue ribbon and of course these clubs seem to be dwindling away with old timers (like me). Getting fresh-meat is a priority.
Toward the end of the day after my last training flight, I asked him to take up my plane. He checked it out thoroughly for settings and balance. Of all the setting (limits, mixing, centering), he had me change only the exponential rate. The instructions with the plane suggested 80% on the first test flights, but he had me reduce it to 30%. He was also concerned that the CG was not forward enough even though the 2200 mAh battery was full forward and I had replaced the rudder with a backup that didn't have the tail wheel. He added about 1/2 ounce.
The new tires worked great on their grass landing strip, but the plastic landing gear is too flexible and the tires tended to toe-in or out causing ground loops. I blame my use of ABS for this as PLA is stiffer. Also, the stock landing gear location does not seem to be far enough forward. It is closer to the spar location instead of the leading edge. This also exacerbated the ground loop and nose plants. After the third attempt (no damage on the previous two) he got it in the air, but I could tell he was fighting the aft CG problem and it was VERY touchy trying to climb/dive. I wanted no part of piloting it! He did several circuits of the field and did improve quickly and did not need to adjust any trim settings. I felt he did a great job of getting it on the ground, but it ground looped almost immediately at full speed and nose planted hard.
The wing came off (rubber bands) but otherwise was unharmed. The landing gear broke right at one of the wheels... understandable as this is where it torques in/out when it ground loops. The fuselage cart-wheeled and broke the rudder off. Otherwise the plane is easily repairable.
As my primary interest is designing and building the airplanes and flying them is really only to validate the desired design or improvement to a design, I'm debating about doing a total blank sheet design. I'd like to explore using the FT foam-board technique / 3D printing design like I'm doing on the F22 Raptor project. Since I'm also tutoring a student who wants to learn aeronautical design concepts AND learn to fly also, it seems like the perfect opportunity.
I may come back to this plane, but I've learned what I need from it and there are lots of things to explore.
