Theory and Practice of Aircraft Performance

CHAPTER 5Aircraft Load

5.1 Overview

An aircraft’s performance depends on its structural integrity to withstand the design load level. Aircraft structures must withstand the imposed load during operations; the extent depends on what is expected from the intended mission role. The higher the load, the heavier is the structure for its integrity; hence the maximum takeoff weight (MTOW) affecting aircraft performance. Aircraft designers must comply with the mandatory certification regulations to meet the minimum safety standards.

The information provided herein is essential for understanding performance considerations that affect aircraft mass (i.e. weight), and hence its performance. The V‐n diagram depicts the loading conditions and the limits of the aircraft flight envelope. Only the loads and associated V‐n diagram in symmetrical flight are discussed herein. Estimation of load is a specialized subject covered in focused courses and textbooks [1]. However, this chapter does outline the key elements of aircraft loads.

5.2 Introduction

Loads are the external forces applied to an aircraft in its static or dynamic state of existence, in flight or on the ground. In‐flight loads are due to symmetrical flight, unsymmetrical flight, or atmospheric gusts from any direction. On‐ground loads result from ground handling and field performance (e.g. in static, takeoff and landing). Aircraft designers must be aware of the applied aircraft loads, ensuring that configurations are capable ...