Theory and Practice of Aircraft Performance

CHAPTER 16Aircraft Sizing and Engine Matching

16.1 Overview

Aircraft sizing and engine matching is a necessary procedure for a new aircraft project, starting early at the conceptual design stage (Phase 1, see Section 1.7). This is to freeze the aircraft configuration to obtain the project go‐ahead decision. The exercise is to ensure the best configuration to satisfy customer specifications and mandatory airworthiness requirements. The procedure does not require full aircraft performance analyses. Only the airworthiness requirements and customer specification requirements are checked out in a parametric search, as will be shown in this chapter. The aircraft sizing and engine matching exercise does not guarantee overall aircraft performance in detail, but makes certain that the new project is capable of meeting the necessary specifications and requirements. The exercise makes use of the aircraft performance analyses, and therefore has to wait until all the related equations are derived as in Chapters 10–15. If required, a family of derivative aircraft can be offered to cover a wider market at a lower development cost by retaining component commonality.

It is assumed here that preliminary aircraft geometry and its component weights are available for the analyses. Engine performance details are given in Chapter 8. Methods for aircraft drag estimation are given Chapter 9. From these building blocks, finally, the aircraft size can be fine‐tuned to a satisfactory configuration offering ...