<< Page 14 Page 15: Page 16 >>   Controls The next three pages will go over airplane control systems, i.e. the mechanisms used by engineers and pilots to make an airplane fly in a desired direction, with a desired orentation. First we'll go over the basics: The three axes (roll, pitch, and yaw), the controls used to fly an airplane (stick and rudder), and the devices that translate inputs on those controls into changes in those axes (elevators, ailerons, and rudders). Then, we'll go into exceptions regarding those devices. Not every airplane has elevators, ailerons, and rudders; Some have elevons, all-moving tailplanes, wing-warping, thrust-vectoring, etc. (The page about this stuff has a really nice thrust-vectoring video which I think is one of the highlights of this website). We will then talk about trim. Trim are the mechanisms that automatically keep an airplane from turning if it is off-balance, e.g. if there is more weight on one side than on the other side, if some damage causes an assymetry in drag, or - most often - while the center of lift of a wing changes as the airplane speed changes. We will then go over stability, which is absolutely key in aircraft design. Stability is an airplane's natural tendency to return to (and stay at) smooth horizontal level flight. Airplanes whose designs are not stable can be very hard to fly (the equivalent of a unicycle, versus a tricycle). And then we'll move on to other performance-related topics like how an airplane's design affects its climbing and turning abilities.