Spoiler Design

1. Introduction Two primary prerequisites for a safe flight are stability and controllability. In addition, pilot and occupant's comfort is of significant importance which is often referred to as handling qualities. These three aircraft design objectives will influence the design of control surfaces and create variety of design constraints. Flight stability is defined as the inherent tendency of an aircraft to oppose any input and return to original trim condition if disturbed. When the summation of all forces along each three axes, and summation of all moments about each three axes are zero, an aircraft is said to be in trim or equilibrium. In this case, aircraft will have a constant linear speed and/or a constant angular speed. Control is the process to change the aircraft flight condition from an initial trim point to a final or new trim point. This is performed mainly by pilot through moving the control surfaces/engine throttle. The desired change is basically expressed with a reference to the time that takes to move from initial trim point to the final trim point (e.g., pitch rate and roll rate).