RE: DD Questions
The trim issue is easy. You are trimming the plane to fly straight when at less than full throttle. This is when the motor torque is causing left roll and since the airflow over the airplane is low it allows the airplane to roll and you are correcting it with right trim. Then when you are at full throttle the apparent engine torque disapears and you still have right trim in and it goes to the right. Prop.... well books have been written about props, the best thing to do as long as you have money is to try as many as you can. What's working for one airplane/ engine/ fuel/ weather combo won't work for another. Slightest things make a difference and the only way to find out is to try it yourself. Airframe noise.... EVERY fast DD that I know of makes this noise, seems to happen with Monokote at about 145mph, sometimes less, sometimes more dependent on weather more than anything. I have the leading edges sheeted on my current version of the Dust and it still does it, seems to come from the large open area towards the rear near the vertical stabs, could be disrupted air coming around the engine???