Quest for Performance: The Evolution of Modern Aircraft
Chapter 11: Early Jet Fighters
[277] A little more than a quarter of a century separated the endings of World Wars I and II. During this time, the maximum speed of propeller-driven fighter aircraft increased from 134 miles per hour for the SPAD XIII to 437 miles per hour for the North American P-51D. Integration of the jet engine with an airframe incorporating selected design innovations such as discussed in chapter 10 resulted in a quantum increase in the capability and performance of fighter aircraft in the decade following the end of World War II. For example, maximum speeds had reached about 1500 miles per hour by 1955. Further increases in the capability of jet fighters and their engines have continued to the present, albeit at a slower pace than that which characterized the first 10 years following the end of World War II.
The missions of fighter aircraft have also changed drastically since they first appeared in World War I. In that conflict, the role of the fighter was described in chapter 2 as follows: "The primary purpose of fighter-type aircraft is to destroy other aircraft, either in offensive or defensive modes of operation, or to pose such a compelling threat that enemy air operations are effectively curtailed." In the 60-plus years since that great conflict, the role of the fighter has so expanded that today this class of aircraft might be described as an all-purpose combat machine. In addition to the air-superiority and interception roles defined above for the World War I time period, the modern fighter may be employed for ground-attack operations, long-range interdiction missions, and photoreconnaissance duties. Indeed, some modern fighter aircraft can carry a greater bomb load than the World War II Boeing B-17 Flying Fortress four-engine bomber. The fighter may be designed and equipped for daylight, clear-weather operations or for night, [278] all weather missions. Frequently, a fighter optimized for one particular type of mission is adapted for other types of operations through changes in design and alterations of armament and mission-oriented electronic gear; thus, for example, an aircraft initially intended as an air-superiority fighter may later be modified for ground-attack missions, and with other alterations, for interceptor use.
The fighter aircraft incorporating jet propulsion form the subject of the present chapter. Beginning in March 1942 with the first flight of the Messerschmitt Me 262 twin-engine jet fighter, the technical evolution of this class of aircraft is traced to the modern fighters of the early eighties. Described and illustrated are 19 jet fighters that show the progression of the state of the art for this type of aircraft over the past 35plus years. As with most successful aircraft, many versions of most of these fighters were developed and used over a period of years. Only one version of each aircraft is described. Works such as reference 200 give the characteristics of most versions of a particular aircraft. Finally, some design trends are discussed in the concluding section.
A number of the physical and performance characteristics of the 19 aircraft described are presented in table V in appendix A. The quantities given in the table are defined in the list of symbols given in appendix B and, in most cases, require no further explanation. Some further clarification of certain of the characteristics, however, seems desirable. Empty weight, normal gross weight, and maximum gross weight are given for many of the aircraft. The normal, or design, gross weight of the aircraft is the maximum weight at which the aircraft can be maneuvered to its design load factor. The maximum gross weight is limited by some design or performance characteristic other than the maximum design load factor. So many range-payload combinations are possible on modern fighter aircraft that no attempt has been made to delineate them in the table. The unrefueled ferry range, however, is given to provide some idea of the capability of the aircraft in this respect. Values of the subsonic minimum drag coefficient and maximum liftdrag ratio given in table V for some of the aircraft are based on information taken from various industrial sources. Finally, the first-flight dates given are for the first prototype of the entire series of aircraft, not necessarily for the particular version for which data are given in the table.