R/C Pattern

摘要

Welcome back, friends. At last month's end we had exploded the myth of the broomstick Pattern plane (I'll bet you never even knew that there was such a myth, but then again anything can happen; after all, we're talking about flying broomsticks!). As it turns out, that myth was simply an invention used to explain the basic rules of pitch trim for an idealized airplane. It is idealized in the sense that only the effects of flying surface alignment, e.g. location and downthrust contribute to its pitch trim in all flight regimes, including the vertical lines and knife edges. This does not necessarily make for a perfect airplane.rnSo we have this idealized plane, but it still has idiosyncrasies. As long as the center of gravity is forward of the neutral point, the plane will rely on some sort of up trim to fly level. The up trim can be reduced but not entirely eliminated by moving the e.g. back closer to the neutral point (NP).