Trivia Teaser: Keeping it centered

True or false: NASA and the USAF designed tailless aircraft. In such aircraft, would it be correct to say that as far as the turn coordinator is concerned, there would be minimal ball movement during all phases of flight?

True. The cause is aerodynamics. A tailless aircraft (in this case the X-36) had no vertical tail. In a conventional aircraft these vertical areas generate some pounds of side force when the aircraft is in uncoordinated flight conditions. This side force is what drives the turn coordinator ball away from its centered position. Minimal vertical area means minimal side force, which means minimal ball movement.