588. The Determination of Center of Gravity Limits and Their Effect on Safety and Performance of Transport Aircraft

Paper

Abstract

The effect of center of gravity limits on the design of a typical jet transport, its structural weight and performance, and the design criteria and aerodynamic characteristics which establish the allowable center of gravity range are presented in qualitative terms.
Effects on aircraft safety and performance from inadvertently exceeding the center of gravity limits are briefly described.
Equations used in evaluating aircraft stability and control characteristics are presented with notations of the aerodynamic and geometric terms used. Certain aerodynamic characteristics have been neglected in the development of these equations to simplify the presentation. Some of the characteristics neglected are the type of control system, aeroelastic effects, power effects, and drag. In a more comprehensive study of stability and control, these characteristics would have to be considered.
Methods are given for improving performance capabilities of aircraft in service by altering the normal center of gravity limits for operations under special conditions.
The effects on an airplane configuration resulting from a design which imposes an excessive range in center of gravity loading limits, an example of how performance is penalized, and the effects of these penalties on the operational economics of a typical transport aircraft are shown.