Quest for Performance: The Evolution of Modern Aircraft
Chapter 5: Design Refinement, 1939-45
[103] The years of World War II saw extensive manufacturing, engineering, and research and development activity in the aviation industry. A similar explosive growth in aeronautical activity occurred during World War I; yet, there was a difference. World War I, as discussed in chapter 2, was characterized by experimentation of all types; different configurations, different materials and types of construction, and radically different types of engines were investigated and tested under actual combat conditions.
The definitive form of the propeller-driven aircraft had crystallized by the beginning of World War II, as discussed in chapter 4. All high-performance military aircraft used in World War II were designed to the same basic formula: internally braced, all-metal monoplane, equipped with retractable landing gear, wing flaps, controllable-pitch propeller, and enclosed compartment for the crew. This design concept was successfully applied to fighters, bombers, observation aircraft, and various other types of aircraft utilized during the war. The emphasis on research, development, and engineering was on achieving higher performance with this standard design formula. The quest was for higher speeds and altitudes, more maneuverability, longer range, better handling characteristics, and means for maintaining the landing speed within acceptable limits. These demands called for lighter weight, stronger structures, higher powered engines, and detailed aerodynamic refinement. The following section briefly describes a few representative areas of aerodynamic refinement.