Quest for Performance: The Evolution of Modern Aircraft
[ix] More than 75 years have passed since the Wright brothers' historic first flight of a powered, heavier-than-air aircraft at Kitty Hawk, North Carolina, on December 17, 1903. During this relatively brief period, the airplane has developed from a useless freak to a highly significant force in modern society. The transformation of the airplane during this period must be ranked as one of the great engineering accomplishments of all time. The magnitude of the achievement is emphasized by the nature of the vehicle and the rigorous requirements for precise design of every element. In no other type of machine, with the possible exception of space vehicles, do the often conflicting requirements of performance, safety, reliability, and economic viability place such a high premium on detailed design optimization, based on quantitative data and analysis.
The evolution of the airplane since 1903 rests on technological advances in such fields as aerodynamics, stability and control, propulsion systems, structures, materials, internal systems, and manufacturing technology. Advancements in all these areas have been made possible by millions of man-hours spent by highly motivated people. Private individuals, research laboratories operated by civil and military elements of the government, and universities-as well as industrial design, research, engineering, and manufacturing teams-have all contributed to the development of the airplane. The evolution of the modern airplane has been characterized by a series of technological levels, or plateaus, that extend over a period of years. Each level has been exemplified by an aircraft configuration type that is gradually improved by a series of relatively small refinements, without any major conceptual change. Under the stimulus of some form of competition, new technology in a number of disciplines has occasionally been combined synergistically in a new design to produce an aircraft of a new and higher level of technology. The Douglas DC-3 transport is a good example of this type of advancement. In a few rare instances, a revolutionary breakthrough or [x] new concept has dramatically altered the course of aeronautical development and established a new and higher technical plateau. The advent of the jet engine and the concept of the swept wing for high-speed flight fall into this category.
Although some further refinement was possible, the technology of the propeller-driven airplane equipped with a reciprocating engine was, at the end of World War II, on a plateau with little expectation of major improvement. In the face of this depressing prospect, aircraft equipped with a new and revolutionary type of propulsion system, the jet engine, appeared on the scene in the closing months of the war. This innovative propulsion system introduced an entirely new level of technology in aircraft design. The subsequent advances in aircraft performance and capability made possible by the turbine engine have perhaps been even more spectacular than those characterized by the first 40 years of powered flight. The initial applications of jet propulsion were to military aircraft of various types. Indeed, the military airplane and the concepts of its various missions went through a complete metamorphosis as a result of this new type of propulsion system. The first jet-powered transport entered commercial operations in 1952. This event heralded the beginning of a revolution in domestic and international air transportation that has accompanied the development and refinement of this type of transport. The entire concept of common-carrier transportation has been radically altered by the jet transport.
This volume traces the technical development of the airplane from a curiosity at the beginning of World War I to the highly useful machine of today. Included are significant aircraft that incorporated important technical innovations and served to shape the future course aeronautical development, as well as aircraft that represented the state of the art of aeronautical technology in a particular time frame or that were very popular and produced in great numbers. In order to reduce the scope of material under consideration, primary emphasis has been placed on aircraft originating in the United States (except in chapter 2). No adverse reflection on the quality of the many fine foreign designs developed over the years is intended by their exclusion. The aircraft described certainly do not include all the significant types designed in the time period 1914-80, but they do illustrate the primary features of the technical evolution of the airplane. If the reader's favorite aircraft is not included, the reference lists at the end of this volume include publications that catalog data and photographs for a wide variety of aircraft.
[xi] The discussion is related primarily to aircraft configuration evolution and associated aerodynamic characteristics and, to a lesser extent, to developments in aircraft construction and propulsion. The book is divided into two parts. Part I deals with the development of propeller-driven aircraft, and part II is devoted to subsonic jet-powered aircraft designed for civil and military use. Some of the jet aircraft described are capable of brief excursions into the realm of supersonic flight; however, long-range supersonic-cruising aircraft are an entirely different class of vehicle and are not discussed in the present volume.
The material is presented in a manner designed to appeal to the nontechnical reader who is interested in the evolution of the airplane, as well as to students of aeronautical engineering or others with an aeronautical background. The use of engineering terminology has been kept at a minimum, consistent with accuracy and the intent of the text; where unavoidable, suitable physical explanations have been included.