I have the Yellow Spitfire and my Son has one too. Together we have over 130 logged flights in the past year. Here is the deal on flaps. Scale position is 85 degrees. That is what you build in. You dump them in right before your turn to final. Dump them all the way. It is wonderful. No perceptable trim change. None. Keep throttle at 25 - 30% and just drive the thing to the ground. A little flare and your down. Best landing Warbird I have ever had my hands on.