RE: RCM Ultra Sport 60 mods
Flight Report ... After arriving and assembling the plane, I proceeded to tune the LSN for idle and transition of the engine. After a few minutes tuning the LSN, it was ready for maiden flight.
Takeoff was smooth and the plane took off after rolling about 30 feet. I set it for a shallow ascending rate while watching for any unexpected tendencies. Made first turn at about 100 feet of altitude and kept the model climbing. I had to change ailerons from low to high rate because it needed more aileron throws. After turning, I started to cut throttle when passing in front of me. Then I let it fly level and kept watching any tendencies while the US was going away from me. Then a second turn to the left for another pass. Again, straight level passes. At this time, I could not say anything more than WOW, NO TRIMMING (left, right, up, or down) NEEDED. Then, I started to continue circling around while cruising at half throttle. I notice the model is still a tad nose heavy for my liking. C.G. was within range while empty. But, at maiden, it had full 14-oz tank. A big adder to nose weight. After a few circles, I gained attitude for flap testing. After applying flaps, I had another WOW. The plane just went UP and UP to almost 60° vertical. Then, I set flaps to normal and resumed normal flight.
Then, landing for checkup...I announced LANDING, first attempt ... it was a surprise seeing the model floating forever. I had to abort landing because ran out of runway at 3-feet from ground. Second attempt...slowed airplane down and set for lower altitude. Again, floated for half runway but it touched ground at 3/4 of runway and slowed down quickly. While taxing back to the pits, the left tire found a small rock on its way and after seeing the small bump, the left block that holds the retract broke and the wing went down; one BIG disappointment for me. So, this was the end of the day for the Ultra Sport.
So, after about seven minutes of flight, information collected pointed to the following changes: move C.G. 1/8" aft, increase aileron throw, lean engine a bit more.
Lesson learned: I need to redo and improve the blocks that hold the retracts. This is my first retract installation. So, I have learned a big lesson about forces that affect retracts.
Overall, it is an amazing model!!!