Conceptual Aircraft Design

18Stability Considerations Affecting Aircraft Design

18.1 Overview

Aircraft performance depends on aircraft stability characteristics. Aircraft stability analyses are subjects of their own but it is necessary to explain some of the pertinent points that affect aircraft performance. Substantiation of aircraft performance by itself would not prove sufficient if the aircraft stability characteristics do not offer satisfactory handling qualities and safety. These characteristics concern aircraft flying qualities (National Aeronautics and Space Administration (NASA) has codified the main flying qualities). Many good designs have had to go through considerable modifications to substantiate aircraft performance and handling criteria. The position of the aircraft centre of gravity (CG) plays an important role in inherent aircraft motion characteristics, which can be seen in how an aircraft performs. This chapter gives a qualitative understanding of the geometrical arrangements of aircraft components affecting aircraft performance associated with stability. Only the equations governing static stability are given to explain some of the important roles in aircraft performance.

This book is not on aircraft stability and control analyses. More details on the subject are given in [1–5]. New generation aircraft incorporate artificial stability technologies – for example, the use of fly‐by‐wire (FBW) technology that are seen as control‐configured vehicles (CCVs) – is not dealt with in this book. ...