Document Type: Engine Operations Manual

Document Number: PWA109702

From the FOREWORD: The aircraft engine is designed to power aircraft in flight. Its construction, installation, servicing, and repair present many interesting and important problems; but its actual operation is, naturally, of more immediate concern to the pilot. A number of texts, handbooks, and manuals are available which discuss the principles of engine design and installation, and describe the procedures of maintenance and overhaul. As a supplement to this material, it is the purpose of this book to discuss the powerplant as a functioning unit and an integral part of the aircraft in which it is installed, and so to provide a basis for an understanding of sound operating practice.

The first part of the book is devoted to a description of the basic engine sections and "systems" which together make up the powerplant, and discusses them in relation to the different instruments and controls by means of which the pilot regulates the performance of his engine. The second part deals with the fundamental concepts of power and its measurement, bmep, and ratings, with particular reference to the principles of engine operation. The last part of the book consists of a set of general operating instructions in which the material treated in the first two parts is applied to the specific problems of engine operation encountered in flight and on the ground. It is assumed that the reader is generally familiar with the main features of conventional engine design, with the names and functions of the more important units of the powerplant, and with the principles of the four-stroke cycle. Many of the numerical values quoted are for the purposes of illustration and may not apply to all engines. Various temperatures are usually given in both Fahrenheit and Centigrade. For easy remembrance most of the temperature values are rounded out, rather than being exact equivalents, except those limits dictated by specification requirements. For specific values for any particular engine consult the applicable Specific Operating Instructions for the engine in question.

The material in the book and its supplements relates principally to the radial, air-cooled engines manufactured by Pratt & Whitney Aircraft, and is based on the experience of more than a quarter of a century in operating these engines.